People often question me about why I stress the importance of reading Charles Darwin's writings rather than relying on modern textbook presentations of evolutionary biology. After all, hasn't there been great progress in biological science since the publication of Darwin's Origin of Species a 150 years ago? This is certainly true. But it is also true that in many respects Darwin's original understanding of evolution is superior to the prevailing views of today's "Neo-Darwinians." Contemporary proponents of Darwinism like Richard Dawkins tell us that biological evolution is ultimately reducible to the natural selection of random genetic mutations. More and more critics are pointing out the flaws in such a genetic reductionist view of evolution, and they are arguing that we need to explain the complex interaction of multiple levels of evolution that cannot be reduced to the gene-centered view of Neo-Darwinism. But if one studies Darwin's writings, one notices that what these critics are proposing is actually a return to Darwin's original theory.
Consider Darwin's summary of his theory in the last paragraph of the Origin:
"It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing a Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."
Notice that Darwin states his "laws" of evolution in a very general and abstract way--the laws of reproduction, inheritance, variability, and struggle for life. If some entities can reproduce themselves, if these entities show heritable variation, and if some of this heritable variation affects their chances of surviving and reproducing in the competitive struggle for existence, then evolution by natural selection will occur. Stated in such a general way, these laws could apply as well to the evolution of human culture as to the evolution of animal anatomy. And, in fact, much of Darwin's Descent of Man is a study of the cultural evolution of human morality.
Notice also that Darwin thinks that heritable variation can arise from "the indirect and direct action of the external conditions of life, and from use and disuse." This means that Darwin embraces Lamarck's idea of the inheritance of acquired characters. So the common story that Darwin overthrew Lamarckianism is false.
In the 1930s, the "Modern Synthesis" of evolutionary biology combined a Neo-Darwinism that rejected all Lamarckianism with Mendelian genetics. It was assumed that genes were the only units of heredity, that variations in genes are random and not affected by the developmental history of the individual, and that selection favors individuals with genes that make them more adapted to their environment than others. Consequently, evolution was understood as some change in the genetic composition of some group of organisms.
In recent decades, empirical research and theoretical arguments have thrown this Modern Synthesis of Neo-Darwinism into doubt, because it seems that a gene-centered theory cannot fully account for the evolution of life. Some people are even saying that this is an intellectual revolution that will destroy Darwinism.
One of the best critiques of Neo-Darwinism is by Eva Jablonka and Marion Lamb, Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life (MIT Press, 2005). But rather than overturning Darwinism, Jablonka and Lamb see their critique as a renewal of Darwin's Darwinism.
The argument of Jablonka and Lamb is that in evolution the genetic system of inheritance is only one of four dimensions of evolutionary inheritance, and that these multiple dimensions of inheritance show a Lamarkian evolution of acquired characters, just as Darwin believed.
To illuminate their general point, Jablonka and Lamb use an analogy to show how different systems of heredity can work along with the genetic system. We can think of a piece of music that is represented by a score, the notes written on paper. This score can be copied as it is passed on through the generations. Although a few mistakes in copying might occur over time, generally the score will be accurately transmitted. We might then see the relationship between the musical score and the musical performance as analogous to the relationship between a genotype and a phenotype in biology. Although mutations in the genotype will be transmitted to future generations, changes in the phenotype will not be transmitted, and so the Lamarckian inheritance of acquired characters does not occur.
But with the invention of new means of transmitting music--such as musical recordings and broadcasts--it becomes possible to transmit the musical performance (the "phenotype") by inheritance. It is also possible that popular performative interpretations of the music might bring notational changes in the score, and in this way the musical "phenotype" would change the musical "genotype."
In a similar way, Jablonka and Lamb argue, there are systems of inheritance beyond the genetic system that allow phenotypic variations to be transmitted across generations. All organisms have two systems of inheritance--the genetic system and the epigenetic system. Many animals have a third system--the behavioral system. Human beings are unique in that they have not only these three systems, but also a fourth--the symbolic system. The full complexity of evolution arises from the intricate interaction of these four dimensions of evolutionary inheritance, which correspond to various levels of complexity from the genome to cells to organisms to groups.
The genetic inheritance system is the foundation for the Neo-Darwinian theory of evolution. Jablonka and Lamb accept this as true, but they also criticize genetic reductionism and determinism for failing to see how gene action depends on the complexity of interacting causes within the genome, within cells, within organisms, within groups of organisms, and within ecological circumstances. Except for a few single-gene genetic disorders, "genetic astrology"--the idea that genes directly control specific traits--must be dismissed as foolish.
The epigenetic inheritance system is evident in the differences between specialized cells. Brain cells, liver cells, and skin cells are very different, although the nucleus of each cell has the same genome. Their differences are epigenetic, rather than genetic, because they have arisen through their developmental history in which there were different patterns of gene activation and interaction within the cell. This developmental information is passed on as these cells divide to produce more cells of the same kind. It is possible for evolution to occur through heritable epigenetic variation even without genetic variation. Just as a musical recording transmits interpretations in musical performances of a musical score, so does an epigenetic inheritance system transmit interpretations of the information in DNA, so that there is a Lamarkian inheritance of phenotypes instead of genotypes. One version of such inheritance that is now under active study is DNA methylation: strands of DNA are chemically modified during development, and these modifications can be transmitted through reproduction.
The behavioral inheritance system is the transmission of information among animals through social learning. For example, among some animals (including human beings) mothers transmit food preferences to their offspring, because information about what mother is eating is transmitted either in the womb or through suckling, so that the offspring inherits a preference for that food. More complex forms of social learning come through animal culture. For example, some chimpanzees can discover how to open nuts with a stone, and then pass on this practice within their group so that it becomes a social tradition. Different communities of chimps in Africa have different cultures based on distinctive profiles of traditional practices transmitted by social learning. As opposed to genetic evolution, cultural evolution is not blind but targeted to functional change.
The symbolic inheritance system is uniquely human because it shows the qualitative leap that defines our humanity as based on our capacity for symbolic thought and communication. Other animals can communicate through signs. But only human beings can communicate through symbols. The evolution of human language was probably crucial for the evolution of symbolism. Symbolic systems allow us to think about abstractions that have little to do with concrete, immediate experiences. Symbolic systems allow human beings to construct a shared imagined reality. These symbolic constructions are often fictional and future-oriented. Art, religion, science, and philosophy are all manifestations of human symbolic evolution. What Karl Jaspers called the Axial Age (600-200 B.C.) would be an example of a turning point in the symbolic evolution of humanity, in which Confucius, the Buddha, the Hebrew prophets, and Plato acted as agents of symbolic innovation that has been inherited across the generations for the last two thousand years.
Neo-Darwinian theorists can hardly deny the reality of symbolic or cultural evolution. So they have developed their own theories of how this works. Dawkins is famous for his theory of "memetics"--the idea that "memes" (units of cultural replication) can evolve as "viruses of the brain." The evolutionary psychologists (like John Tooby and Leda Cosmides) explain cultural evolution as a historical process of social learning constrained by the genetically evolved biases of the brain. Although Jablonka and Lamb see some partial truth in these approaches, they also see them as inadequate for explaining the uniqueness of symbolic evolution as shaped through the constructive activities of individual and social agents in history.
The four-leveled account of evolution could explain Aristotle's biological studies of political animals. Human beings are not the only political animals, Aristotle observed, but human beings are more political than the other political animals because the human capacity for logos--speech or conceptual reasoning--allows human beings to organize their political life around shared conceptions of the good and the just. Jablonka and Lamb might say that while human beings share with other animals a capacity for political culture based on behavioral inheritance, only human beings have a capacity for political symbolism that creates a shared symbolic meaning for political life.
I will be writing more posts on these four dimensions of evolution.
Showing posts sorted by relevance for query evolution in four dimensions. Sort by date Show all posts
Showing posts sorted by relevance for query evolution in four dimensions. Sort by date Show all posts
Saturday, February 20, 2010
Monday, December 15, 2025
If Humans and Chimps Are 15 Percent Genetically Different, What Difference Does That Make?
Think about how often you've heard it said that the genetic difference between human beings and chimpanzees is only slightly more than 1 percent, and therefore humans are 99 percent similar to chimps. It is also said that this proves that chimps--and also bonobos--are our closest living evolutionary relatives. This seems to be confirmed by the fact that chimpanzees and bonobos are more genetically similar to humans than to gorillas. This 1 percent difference between humans and chimps fits the evolutionary timeline of five to eight million years since humans and chimps diverged from their last common ancestor.
But now an article published last May in Nature (Yoo et al., 2025) reports that a complete sequencing of ape genomes shows that the genetic difference between humans and chimps is a lot greater than 1 percent--more like 15 percent! And yet perhaps I shouldn't say this article "reports" this because if you read the main article, you won't see this claim of a 15 percent difference. You have to go to the Nature website and print out the "Supplementary Data" for the article, and even then, you have to work through the technical jargon to find the 15 percent difference. Casey Luskin has posted a helpful article at the Discovery Institute website that digs deep into the "Supplementary Data" to uncover this remarkable finding. You would think that such a surprising discovery would be prominently announced in Nature and in press releases: "The Chimp-Human Genetic Difference Is Not 1% But 15%!" I think Luskin is right to suggest that the editors at Nature must have worked hard to hide this finding because it refutes the popular claim about "only a 1% difference" separating humans and chimps.
Luskin says this refutes one of the "icons of evolution," as Jonathan Wells called them--that is, widely believed assertions about evolution that the proponents of "intelligent design theory" and "young-Earth creationism" deny. It's not surprising, therefore, that creationists like Ken Ham have cited Luskin's article as proving that the creationists are right to deny that there is any common evolutionary ancestry linking humans and apes. Ham explains that Bible teaches us that God created the "ape kind" and the "humankind" separately and created humans as a unique kind made in the image of God.
And yet I don't see that this newly discovered "15% difference" provides any support for the intelligent design theorists or the creationists in their denial of evolutionary science.
But first we need to understand how this new research allows us to calculate genetic difference and similarity. The title of the article in Nature is "Complete Sequency of Ape Genomes." The emphasis is on "complete," because the first human and ape genome sequences were incomplete. They excluded extremely repetitive sequences and large-scale structural differences such as inversions and duplications of genomic sequences. So the first reports of only 1% differences between human and chimp genomes were based on incomplete drafts of the genomes. But now the complete sequency in this article allows for a fuller comparison of similarities and differences in the sequences.
The authors found two kinds of differences--"gap divergence" and "single nucleotide variation" (SNV).
Luskin prepared this figure to illustrate the difference between "SNVs" and "Gaps" between two genomes. Gaps represent nucleotides or segments of nucleotides that don't exist in one of the genomes. SNVs represent places where the nucleotides are different for the two genomes. In this illustration, we have 30 nucleotides of the target genome with 3 SNVs and 9 gaps relative to the query genome. So SNV divergence is 10%, and gap divergence is 30%, which means a total divergence of 40%.
If you go to the Supplemental Data for the Yoo et al. article, you will see that Figure III.12 shows the SNVs in comparing the genomes for humans, chimpanzees, bonobos, and orangutans--the four "great ape" species who belong to the Hominidae family. When the human genome is the "target" genome, the "gap divergence" for the gorilla genome is 27.3 percent, for the Sumatran orangutan it's 16.5 percent, for the bonobo it's 14.4 percent, and for the chimpanzee it's 13.3 percent.
Figure III.11 shows the SNV divergences, which are 2 percent for the gorilla, 3.6 percent for the Sumatran orangutan, 1.6 percent for the bonobo, and 1.6 percent for the chimpanzee.
If we add the gap divergences to the SNV differences, we get these total degrees of difference between human and ape genomes: 29.3 percent for the gorilla, 20.1 percent for the Sumatran orangutan, 16 percent for the bonobo, and 14.9 percent for the chimpanzee. That's how we get the estimate of almost 15 percent difference between the chimp and human genomes, which is a lot higher than the purported 1 percent difference.
It should be noted that these comparisons are for the 44 non-sex chromosomes in the human genome--that is, excluding the X and Y chromosomes. As compared with chimps, the human X chromosome has a 4.4 percent gap divergence and 1.1 percent SNV divergence, while the human Y chromosome has an amazing 56.6 percent gap divergence and 3.9 percent SNV divergence.
Although this new research shows that the genetic differences between humans and apes are greater than had been previously reported, this does not deny the evolutionary story of the common evolutionary ancestry of humans and apes. The genetic similarity between humans and apes is still very great--85 percent! And humans are more genetically similar to chimps and bonobos than they are to orangutans and gorillas, which supports the claim that chimps and bonobos really are our closest living evolutionary relatives.
ALL IN THE GENES? OR FOUR DIMENSIONS OF EVOLUTION?
There is an obvious problem here, however. All of us have seen chimpanzees in zoos. And many of us have seen bonobos if we have gone to zoos in San Diego, Milwaukee, or Cincinnati that have bonobos. Those zoos often have displays that say something about the 1 percent difference between humans and chimpanzees. Now those displays might have to be changed to read 15 percent. But even so, when we look at those apes and compare them with humans, it's very hard to believe that the difference is only 1 to 15 percent. It's simply not true that humans and apes are 85 percent the same. The gap between the mental achievements of human beings and those of the apes is staggering.
Most human beings don't believe that evolutionary genetics can fully explain that gap, and that's why so many people reject the science of evolution, and why so many believe that the superiority of the human mind over the ape mind can only be explained by the supernatural work of an Intelligent Designer or Divine Creator.
They are right to believe that evolutionary genetics cannot fully explain the achievements of the human mind. But that's because genetics is only a small part of evolutionary science. As I have indicated in some previous posts, there are four levels of evolutionary inheritance--genetics, epigenetics, culture, and symbolism (Jablonka and Lamb, 2005).
The genetic inheritance system is the foundation for the Neo-Darwinian theory of evolution. But genetic reductionism and determinism fail to see how gene action depends on the complexity of interacting causes within the genome, within cells, within organisms, within groups of organisms, and within ecological circumstances. Except for a few single-gene genetic disorders, "genetic astrology"--the idea that genes directly control specific traits--must be dismissed as foolish.
The epigenetic inheritance system is evident in the differences between specialized cells. Brain cells, liver cells, and skin cells are very different, although the nucleus of each cell has the same genome. Their differences are epigenetic, rather than genetic, because they have arisen through their developmental history in which there were different patterns of gene activation and interaction within the cell. This developmental information is passed on as these cells divide to produce more cells of the same kind. It is possible for evolution to occur through heritable epigenetic variation even without genetic variation. Just as a musical recording transmits interpretations in musical performances of a musical score, so does an epigenetic inheritance system transmit interpretations of the information in DNA, so that there is a Lamarkian inheritance of phenotypes instead of genotypes. One version of such inheritance that is now under active study is DNA methylation: strands of DNA are chemically modified during development, and these modifications can be transmitted through reproduction. The chemical modification in epimutation is not in the DNA itself but in the chromatin marking. Methylated DNA has a small methyl group attached to some of its bases. The pattern of methylation influences which regions of DNA are expressed. The different kinds of cells in the human body have the same DNA, but the different patterns of methylation regulate the expression of DNA.
The behavioral inheritance system is the transmission of information among animals through social learning. For example, among some animals (including human beings) mothers transmit food preferences to their offspring, because information about what mother is eating is transmitted either in the womb or through suckling, so that the offspring inherits a preference for that food. More complex forms of social learning come through animal culture. For example, some chimpanzees can discover how to open nuts with a stone and then pass on this practice within their group so that it becomes a social tradition. Different communities of chimps in Africa have different cultures based on distinctive profiles of traditional practices transmitted by social learning. As opposed to genetic evolution, cultural evolution is not blind but targeted to functional change.
The symbolic inheritance system is uniquely human because it shows the qualitative leap that defines our humanity as based on our capacity for symbolic thought and communication. Other animals can communicate through signs. But only human beings can communicate through symbols. The evolution of human language was probably crucial for the evolution of symbolism. Symbolic systems allow us to think about abstractions that have little to do with concrete, immediate experiences. Symbolic systems allow human beings to construct a shared imagined reality. These symbolic constructions are often fictional and future-oriented. Art, religion, science, and philosophy are all manifestations of human symbolic evolution.
To explain why humans are somewhat similar to the great apes and yet radically different from them, we have understand how all four levels of human evolution have shaped human beings to be the unique animals that they are.
COMMON DESCENT OR INTELLIGENT DESIGN? OR BOTH?
Although Casey Luskin is an advocate of intelligent design theory as the best alternative to evolutionary science, he stresses that he is not pointing to the new estimate of 15 percent difference between humans and chimps as evidence that refutes evolution. As long as the five to eight million years since humans and chimps diverged from their last common ancestor is enough time for this 15 percent difference to evolve, then the evolutionary story of common ancestry is still defensible.
But still, Luskin suggests, intelligent design theory has a better explanation for this genetic similarity--85 percent--between chimps and humans: "Functional genetic similarities between humans and chimps could be explained by common ancestry or by common design. Common ancestry is not the only way to explain genetic similarities. Intelligent agents can re-use functional code in different designs. Common design can explain shared functional genetic similarities just as well as common descent can."
There are two mistakes in Luskin's reasoning, however. First, he mistakenly assumes a dichotomy between common descent and common design, as if they were mutually exclusive. As I have noted previously, one of the leading advocates of intelligent design theory--Michael Behe--argues (in The Edge of Evolution) that the genetic similarity between humans and chimps is evidence that human beings evolved from primate ancestors shared with chimpanzees. He explains that intelligent design is required to explain the emergence of the higher taxonomic levels of life (kingdoms, phyla, classes) but not the lower levels (orders, families, genera, species). This means that the evolution of species could be fully Darwinian.
Behe is an intelligent-design evolutionist, because he insists: "The possibility of intelligent design is quite compatible with common descent, which some religious people disdain. What's more, although some religious thinkers envision active, continuing intervention in nature, intelligent design is quite compatible with the view that the universe operates by unbroken natural law, with the design of life perhaps packed into its initial set-up" (166). Luskin refuses to recognize Behe's position.
Luskin is also mistaken, however, in assuming the plausibility of the arguments for intelligent design. He thus ignores my objection that the arguments for intelligent design are fallacious in two respects. First, intelligent design reasoning depends completely on the fallacy of negative argumentation from ignorance, in which intelligent design proponents argue that if evolutionary scientists cannot fully explain the step-by-step evolutionary process by which complex living forms arise, then this proves that these complex forms of life must be caused by the intelligent designer. This is purely negative reasoning because the proponents of intelligent design can offer no positive explanation of their own as to exactly when, where, and how the intelligent designer caused these forms of life.
The second fallacy is the subtle use of the fallacy of equivocation--in the equivocation between human intelligent design and supernatural intelligent design. We have all had the experience of seeing how human intelligent agents create artificial products by intelligent design. But it does not follow logically from this that we have all had the experience of seeing how supernatural intelligent agents create artificial products by intelligent design.
CREATED BY GOD IN HIS IMAGE? OR EVOLVED IN THE IMAGE OF PRIMATES? OR BOTH?
Ken Ham (2025) argues, on the contrary, that even if we have not seen with our own eyes God creating everything out of nothing, this has been revealed to us through the Bible; and part of that revelation is that God created all the "kinds" of plants and animals separately, and He created the "chimp kind" to be utterly different from the "humankind," which was created in His image.
But as I have said in my previous posts on Ham and his two museums in Kentucky--the Creation Museum and the Ark Encounter--he mistakenly assumes that he is conveying the clear meaning of the Bible and that the Bible's clear teaching is incompatible with Darwinian evolution.
The Bible says nothing about God creating apes and humans as separate "kinds." The Book of Genesis never mentions apes. Actually, in the whole Bible, the Hebrew word for "ape" appears only twice (I Kings 10:22, 2 Chronicles 9:21), and never in the context of creation. And while Genesis speaks of God creating plants and animals "after their kind," it never identifies human beings as a "kind." Consider Genesis 1:26--"And God said, Let us make man in our image, after our likeness." The phrase "after our likeness" takes the place of "after their kind," suggesting that in being created in the likeness of God, man is not bound by a "kind." So there is no Biblical basis for Ham to speak of "humankind."
Moreover, the Hebrew word min that is translated as kind in the King James Bible is ambiguous. In the Latin translation of the Bible, min is translated as the Latin word species. Consequently, for almost two thousand years, Biblical believers assumed that God's creating "kinds" meant that God created each "species" separately, and that each species was eternally fixed. But then after Darwin published his Origin of Species in 1859, in which he argued against the "theory of special creation" that God had created each species separating, some Christians began to believe that the created "kinds" in the Bible referred not to "species" but to some higher level of taxonomy. Then, in 1941, the Christian biologist Frank Marsh coined the word baramin (combining the Hebrew words for "created" and "kind") as the best term for "created kind." He argued that a "created kind" was not at the taxonomic level of "species" but at or near the level of "family." This allowed Biblical believers to accept Darwin's theory of the origin of "species" by natural selection while also believing that God had created the "families" of plants and animals to be fixed and separate. So, for example, we could say that God originally created the "family" of the finches, but within the limits of that "family," the separate species of finches endemic to the Galapagos Islands evolved by natural selection to be adaptive to those islands.
Notice what this means for the taxonomic classification of human beings. If the "kind" of human beings refers to their taxonomic "family," then in modern taxonomy, human beings belong to the "family" of Hominidae, which includes chimps, bonobos, gorillas, and orangutan. Even the young-earth creationist Todd Wood (2010) accepts this Hominidae classification of humans with the great apes, although he identifies the "human holobaramin" as the genus Homo.
This idea of "created kinds" was crucial for Ham in solving an old problem with Noah's Ark. If the Ark carried all the "kinds" of land-based plants and animals, how could the Ark be big enough to hold all of the land-based species--which could be numbered in the millions?
Ham's creationist researchers have solved this problem by calculating that among these land-dependent vertebrate species, there are fewer than 1,400 known living and extinct kinds (that is, families). This allows them to estimate that Noah had to have fewer than 6,744 individual animals on the Ark. Once these animals left the Ark, speciation by natural selection within kinds could create all the living and extinct species that we know today. The Ham's Ark Encounter is designed to show how as many as 6,744 animals and 8 human beings (Noah and his extended family) could survive on the Ark for almost a year. But notice that this is a speculative reading of the Bible that never defines "kind" in this way. This is not the clear meaning of the Bible, as Ham claims. Indeed, if you go to the Ark Encounter in Kentucky, you might notice one display that speaks of the need for "Arktistic license" in making up details in the story of the Ark that have no basis in the Bible.
Since the Bible is so obscure in its creation story, and since so much of that story sounds like a figurative folk tale that was not meant to be a literal account of natural history, many Christians (like C. S. Lewis, Francis Collins, and Deborah Haarsma) have decided that the Bible could be read as allowing for theistic evolution or evolutionary creation. According to this conception, God created the universal laws of nature at the beginning of the Universe, but then He allowed all the forms of life to emerge by natural evolution. God is the "primary cause" of everything. But the evolutionary process unfolds through the "secondary causes" of nature. Even Darwin himself accepted this metaphysical conception of "dual causality" that reconciles belief in God as First Cause with acceptance of evolutionary science. At various points in the Creation Museum and the Ark Encounter, there are displays that acknowledge that many if not most Christians accept some version of this theistic evolution.
But what about the creation of human beings in the image of God? If the "image of God" refers to the God-like intellect of man, then we might argue that the extraordinary mental capacities of human beings could have evolved through the evolution of the primate brain. I have argued that the evolution in the size and complexity of the primate brain passed over a critical threshold so that now there are 86 billion neurons in the human brain, and of that total, 16 billion are in the cerebral cortex, which includes 1.3 billion neurons in the prefrontal cortex. That emergent evolution of the brain created the uniquely powerful human mind. We were created in the image of the primate brain.
Even if we are only 15 percent genetically different from chimps, we are different in kind from chimps because we have the mental capacities for language, morality, and symbolic abstraction that they do not have at all. That's the difference that makes all the difference.
REFERENCES
Behe, Michael. 2007. The Edge of Evolution: The Search for the Limits of Darwinism. New York: The Free Press.
Ham, Ken. 2025. "Study Finds Chimp DNA Is Not '99% Identical' to Ours." Answers in Genesis. Ken Ham Blog. May 27. Online.
Jablonka, Eva, and Marion J. Lamb. 2014. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Revised edition. Cambridge: MIT Press.
Luskin, Casey. 2025. "Fact Check: New 'Complete' Chimp Genome Shows 14.9 Percent Difference from Human Genome." Science and Culture Today, May 21, online.
Wood, Todd Charles. 2010. "Baraminological Analysis Places Homo habilis, Homo rudolfensis, and Australopithecus sediba in the Human Holobaramin." Answers Research Journal 3: 71-90.
Yoo, Dong Ahn, et al. 2025. "Complete Sequencing of Ape Genomes." Nature 641: 401-418.
Wednesday, April 15, 2009
Does Evolution Explain Human Nature?
Does evolution explain human nature?
That's the question posed by the John Templeton Foundation to a dozen scholars of biology--Francisco Ayala, Francis Collins, Eva Jablonka, Lynn Margulis, Geoffrey Miller, Simon Conway Morris, Martin Nowak, Joan Roughgarden, Jeffrey Schloss, Frans de Waal, David Sloan Wilson, and Robert Wright. Each wrote a brief essay in response. All of the essays can be found on the Templeton website.
These essays challenge four of the major misconceptions about evolutionary explanations of human nature. It is often said that such evolutionary reasoning (1)promotes atheism, (2) assumes genetic determinism, (3) subverts morality, and (4)denies the wondrous mysteries of life.
All of these authors accept the truth of evolutionary reasoning in explaining--either partly or entirely--the complexity of human nature. Some of them are religious believers, and two of them (Collins and Nowak) write about their Christian beliefs. Some of the others speak about the importance of explaining the evolutionary origins of religiosity.
That genetic determinism is insufficient for explaining human nature is a major theme for nine of the authors (Ayala, Collins, Jablonka, Margulis, Miller, Morris, Nowak, Schloss, and Wilson). Margulis speaks about "symbiogenesis, the evolution of new species from the coming together of members of different species," and this goes beyond random genetic mutations. Many of these authors stress the importance of cultural evolution, particularly through the human capacity for symbolism. An evolutionary explanation of human nature requires an account of the complex interaction of genetic evolution and cultural evolution.
The most interesting essay on the multi-leveled character of human evolution is Jablonka's. She suggests that an evolutionary explanation of human nature would have to reformulate Aristotle's biological psychology in an evolutionary framework. Aristotle explained human nature--particularly in the De Anima--as manifesting three levels: goal-directed living systems, animal mentality, and human thought. She argues that evolutionary explanations must move through these levels. We need to define evolution as "the set of processes that lead to changes in the nature and frequency of heritable types in populations over time." These "heritable types" include "genotypes, types of transmissible epigenetic (that is, developmentally acquired) variations, types of socially learned animal behavior, and types of symbol-based transmitted information." Jablonka's reasoning is elaborated in her book Evolution in Four Dimensions, which supports the same complex view of human evolution that I will develop in my new book.
Against the claim that a Darwinian view of human nature denies the importance of morality, six of the authors (Ayala, Collins, Jablonka, Margulis, de Waal, Wilson, Wright) emphasize the importance of morality for human evolution. Although the capacity for human morality is rooted in human genetic evolution, the development of moral experience depends on human cultural evolution.
Here is where I would say that we need to move through three levels of analysis--natural order, customary order, and deliberate judgment. The evolutionary history of human morality shows the universality of moral sentiments, the variability of moral traditions, and the individuality of moral judgments.
Many people think that evolutionary explanations of human nature gloss over the deep mysteries of the human condition. But some of these authors (especially, Collins, Nowak, and Wright) insist that evolutionary science forces us to confront the inescapable mysteries of human life. Collins writes: "We see science as the way to understand the awesome nature of God's creation and as a powerful method for answering the 'how' questions about the universe. But we also see that science is powerless to answer the fundamental 'why' questions, such as 'Why is there something instead of nothing?,''Why am I here?,' and 'Why should good and evil matter?'" Nowak speaks of "the mystery and purpose of life, which cannot be answered by natural science alone." And Wright points to two "awe-inspiring mysteries"--the mystery of the cosmic First Cause and the mystery of consciousness.
Nowak thinks another kind of mystery is manifested in mathematics: "the great theorems of mathematics are statements of an eternal truth that comes from another world, a world that seems to be entirely independent of the particular trajectory that biological evolution has taken on earth." We must wonder how "evolution has led to a human brain that can gain access to a Platonic world of forms and ideas."
The conclusion I draw from all these essays is that an evolutionary explanation of human nature requires a combination of all the traditional intellectual disciplines--in the natural sciences, the social sciences, and the humanities--as we strive for a Darwinian liberal education in pondering the deepest questions of human existence.
That's the question posed by the John Templeton Foundation to a dozen scholars of biology--Francisco Ayala, Francis Collins, Eva Jablonka, Lynn Margulis, Geoffrey Miller, Simon Conway Morris, Martin Nowak, Joan Roughgarden, Jeffrey Schloss, Frans de Waal, David Sloan Wilson, and Robert Wright. Each wrote a brief essay in response. All of the essays can be found on the Templeton website.
These essays challenge four of the major misconceptions about evolutionary explanations of human nature. It is often said that such evolutionary reasoning (1)promotes atheism, (2) assumes genetic determinism, (3) subverts morality, and (4)denies the wondrous mysteries of life.
All of these authors accept the truth of evolutionary reasoning in explaining--either partly or entirely--the complexity of human nature. Some of them are religious believers, and two of them (Collins and Nowak) write about their Christian beliefs. Some of the others speak about the importance of explaining the evolutionary origins of religiosity.
That genetic determinism is insufficient for explaining human nature is a major theme for nine of the authors (Ayala, Collins, Jablonka, Margulis, Miller, Morris, Nowak, Schloss, and Wilson). Margulis speaks about "symbiogenesis, the evolution of new species from the coming together of members of different species," and this goes beyond random genetic mutations. Many of these authors stress the importance of cultural evolution, particularly through the human capacity for symbolism. An evolutionary explanation of human nature requires an account of the complex interaction of genetic evolution and cultural evolution.
The most interesting essay on the multi-leveled character of human evolution is Jablonka's. She suggests that an evolutionary explanation of human nature would have to reformulate Aristotle's biological psychology in an evolutionary framework. Aristotle explained human nature--particularly in the De Anima--as manifesting three levels: goal-directed living systems, animal mentality, and human thought. She argues that evolutionary explanations must move through these levels. We need to define evolution as "the set of processes that lead to changes in the nature and frequency of heritable types in populations over time." These "heritable types" include "genotypes, types of transmissible epigenetic (that is, developmentally acquired) variations, types of socially learned animal behavior, and types of symbol-based transmitted information." Jablonka's reasoning is elaborated in her book Evolution in Four Dimensions, which supports the same complex view of human evolution that I will develop in my new book.
Against the claim that a Darwinian view of human nature denies the importance of morality, six of the authors (Ayala, Collins, Jablonka, Margulis, de Waal, Wilson, Wright) emphasize the importance of morality for human evolution. Although the capacity for human morality is rooted in human genetic evolution, the development of moral experience depends on human cultural evolution.
Here is where I would say that we need to move through three levels of analysis--natural order, customary order, and deliberate judgment. The evolutionary history of human morality shows the universality of moral sentiments, the variability of moral traditions, and the individuality of moral judgments.
Many people think that evolutionary explanations of human nature gloss over the deep mysteries of the human condition. But some of these authors (especially, Collins, Nowak, and Wright) insist that evolutionary science forces us to confront the inescapable mysteries of human life. Collins writes: "We see science as the way to understand the awesome nature of God's creation and as a powerful method for answering the 'how' questions about the universe. But we also see that science is powerless to answer the fundamental 'why' questions, such as 'Why is there something instead of nothing?,''Why am I here?,' and 'Why should good and evil matter?'" Nowak speaks of "the mystery and purpose of life, which cannot be answered by natural science alone." And Wright points to two "awe-inspiring mysteries"--the mystery of the cosmic First Cause and the mystery of consciousness.
Nowak thinks another kind of mystery is manifested in mathematics: "the great theorems of mathematics are statements of an eternal truth that comes from another world, a world that seems to be entirely independent of the particular trajectory that biological evolution has taken on earth." We must wonder how "evolution has led to a human brain that can gain access to a Platonic world of forms and ideas."
The conclusion I draw from all these essays is that an evolutionary explanation of human nature requires a combination of all the traditional intellectual disciplines--in the natural sciences, the social sciences, and the humanities--as we strive for a Darwinian liberal education in pondering the deepest questions of human existence.
Thursday, July 21, 2016
Lucretius in the Evolution/Creation Debate
From ancient Greece and Rome to the present, one of the fundamental debates in human history has been over a deep question: Is our universe mindful and purposive or mindless and material? Do we live in a cosmos that was intentionally created by a divinely intelligent designer who cares for us and judges us by his moral law? Or do we live in a cosmos that arose unintentionally by natural evolution through chance and necessity with no concern for us or any moral law?
Today, this debate is between the creationists or intelligent design theorists, on the one side, and the Darwinian evolutionists, on the other side. Some theistic evolutionists (like Francis Collins or Owen Gingerich, for example) have tried to take a third position: that the Creator has designed the parameters of certain natural constants so that cosmic evolution is fine-tuned for producing intelligent human life as the fulfillment of the Creator's purposes.
In ancient Greece, some of the pre-Socratic natural philosophers (like Empedocles and Democritus) developed materialist or mechanist explanations for how the world and all living beings in it could have emerged by natural causes without any divine design or purpose. In some of Plato's dialogues--particularly in book 10 of the Laws and in the Timaeus--this anti-teleological cosmology was rejected as a dangerous atheism that would subvert the moral and political order of human life. Plato's Athenian Stranger (in the Laws) argues that everyone in the political order he proposes must believe that the gods exist, that the gods think about and care for human beings, and that the gods enforce justice by rewarding the good and punishing the bad. Those people who openly question this cosmic theology should be imprisoned, and if they cannot be persuaded to accept this theology, they will be punished with death. Plato's Timaeus argued that people should be taught that everything was created by a divine Demiurge or Craftsman assisted by other gods according to a model of an eternally enduring nature, so that the cosmos could be seen as the best of all possible worlds.
Later, Epicurus challenged this Platonic cosmic teleology by developing his own anti-teleological cosmology based on the atomistic science of Democritus. Everything could be understood as the patterns of order arising from the combining and dissolving of atoms moving in a void, so that all possible combinations of these atoms would arise as worlds coming into being and passing away. All life is mortal, so there is no afterlife, and no divine judgment of human beings after death. The gods exist, but they live outside the world of human experience, and they do not care for or intervene in human affairs. All of the organized religions that teach that the gods have created the world and judge human beings both in this life and in the afterlife deprive human beings of happiness by promoting a fear of death and of divine judgment that creates unnecessary and unreasonable anxiety.
Epicureans can be happy because they don't fear god, they don't worry about death, they know that the goodness of pleasure is usually easy to get, and they know that the badness of pain is usually easy to endure. This is possible because their freedom from religious fears and their understanding of how everything is ultimately explained by natural causes allows them to live out their mortal lives with tranquil minds.
Although Epicurus wrote many books, most of his writing has been lost, and we now have only fragments quoted by other writers. The most extensive text of Epicurean philosophy is the Latin philosophical poem of Lucretius--De Rerum Natura (On the Nature of Things)--which he wrote sometime before his death in 55 B.C. Although he does not mention Plato by name, Lucretius can be seen as defending the Epicurean anti-teleological cosmology against the Platonic teleological cosmology, particularly as it was reformulated by the Stoics.
Christian theologians were able to accept modified forms of the Platonic and Stoic cosmology of divine creation as compatible with Biblical creationist theology, which became the predominant model of the cosmos in Christendom for over 1,500 years. But Christians had to scorn the Epicurean/Lucretian cosmology of materialist atomism as promoting a dangerously atheistic view of the universe.
The texts of Lucretius' book were either destroyed or hidden away, until a text was rediscovered in 1417 by Poggio Bracciolini. Many early modern philosophers and scientists could then see the Lucretian materialist and anti-teleological model of the cosmos as the alternative to the creationist and teleological model of Christian cosmology.
Finally, with the publication in 1859 of Charles Darwin's On the Origin of the Species, the Darwinian theory of the evolution of species by natural selection in the struggle for survival seemed to provide a modern scientific version of Lucretian cosmology as an alternative to Christian creationism. If so, then the debate between evolutionists and creationists today continues the debate between Platonists and Epicureans over whether the cosmos has been intelligently and purposefully designed or not.
As I have indicated in some previous posts, this cosmological debate is also a moral and political debate, because while the Platonic/Christian cosmology of order as a top-down imposition of intentional planning seems to support moral and political authoritarianism, the Epicurean/Darwinian cosmology of order as a bottom-up emergence of spontaneous order seems to support moral and political liberalism.
But is it really true that the Epicurean cosmology of Lurcretius' book conforms to a Darwinian evolutionary conception of the universe? Gordon Campbell (a classics scholar) has helped me to think about this through one of his papers--"Zoogony and Evolution in Plato's Timaeus: The Presocratics, Lucretius, and Darwin" (2000)--and one of his books--Lucretius on Creation and Evolution (2003). Campbell's writing illuminates Lucretius' place in the evolution/creation debate from ancient Greece to the present.
And yet I do disagree with Campbell on four points. First, I disagree with his claim that the only "fully evolutionary theory" of the cosmos in the ancient world is in Plato's Timaeus (Campbell 2003, 2). He distinguishes between two kinds of evolution (Campbell 2000, 14). "Inter-specific evolution" is "the Darwinian model of the origin of species by the gradual accumulation of variation over time leading to the formation of new species." "Intra-specific evolution" is "the accumulation of variation within a species that stops short of crossing species boundaries." He claims that Plato is the only ancient proponent of Darwinian inter-specific evolution, because Plato's Timaeus describes an evolutionary process in which the Demiurge first creates human beings and then morally degenerate human beings evolve into four kinds of animals--birds, footed land animals, footless land animals, and fish--with the animals ranked from the more thoughtful animals to the thoughtless animals.
The first problem with Campbell's claim is that what Timaeus describes is not a natural evolutionary process at all, because he asserts it to be the work of divine creation by the Demiurge and the other gods (Timaeus 41a-d, 92c).
The second problem is that it's not clear that Plato or Plato's Socrates endorses Timaeus's story of cosmic creation. Timaeus's story is so utterly ridiculous that many readers have doubted that Plato takes it seriously. A. E. Taylor, for example, made this point, but Campbell casually dismisses this and insists that Timaeus's story must be seen as a serious teaching of Plato (2000, 158). But Campbell doesn't explain the many strange features of this dialogue. First of all, it's not much of a dialogue. After some brief exchanges between Socrates and Timaeus, Timaeus launches into a long lecture that takes up most of the book. Socrates remains silent, which suggests that Timaeus's story cannot withstand any Socratic questioning. Timaeus says that his story will be a "likely myth." Socrates says that it will be a nomos--a song, a custom, or a law (Timaeus 29d). So Timaeus's story is not a reasoned account of the cosmos.
Moreover, what Timaeus says is often self-contradictory. For example, Timaeus says that the best account of astronomy depends on sight--looking at the stars and the Sun--and this shows the primacy of our eyes for our knowledge of the world (47a-c). But then he condemns as "light-minded" the empirical astronomers who believe that our knowledge of astronomy must begin with what we can see with our own eyes. Such people are punished by being turned into birds (91d-e).
My point here is that Campbell does not consider the possibility that while Plato might have thought that a teleological cosmology of divinely intelligent design could be a salutary belief for many people, it could not be a rational account of the cosmos for natural philosophers. Aristotle suggested this in observing that such cosmic myths were little more than traditional folk tales (On the Heavens, 270b1-25, 283b26-284b5, 291b24-292a20, 298b6-299a2; The Movement of Animals, 699b12-31; Metaphysics, 1050b20-25, 1074b1-14).
Not only do I think Campbell is wrong in identifying Plato as an evolutionist, I also think he is wrong in denying that Lucretius was an evolutionist. This is my second point of disagreement. Although Campbell is right in noting that Lucretius never explicitly affirms the "inter-specific evolution" of a new species from an ancestral species, Lucretius does at least implicitly suggest that human beings have evolved from an earlier species that was human-like but not fully human, because it did not have the human digestive system that requires food cooked with fire. Lucretius could not explicitly elaborate this idea, because he lacked the evidence for human evolution that is available today--including the fossil record, the archaeological record, human physiology, and comparative primatology.
In Book 5 of De Rerum Natura, Lucretius explains the origin of all living beings as the spontaneous generation of life from the Earth (5.785-1012). Just as today we can see the spontaneous generation of worms and cicadas from the Earth, Lucretius claims, we can imagine that at the beginning the Earth was so fertile that it could generate all forms of plant and animal life (2.871-72, 898-901, 928-29, 3.719-36, 5.797-98). For this reason, Lucretius observes, the Earth has rightly been called the Mother of all life.
At first, the Earth experimented with many monstrous animal bodies with grotesque appearance--such as animals that were both male and female, animals without feet or hands or mouths. These forms of life "were created in vain," because nature extinguished them. They died from starvation. Or they could not reproduce. Or they could not compete with other animals. Only those species adapted for survival, reproduction, and competition were naturally selected for preservation. Those human beings who lived in these early days were tougher and larger than human beings today. They lived as solitary foragers and like savage beasts, with no families, no farming, no customs or laws, no use of fire or clothing. Men and women came together for sexual copulation and then separated with no enduring attachment. (Here is where Rousseau found his first "state of nature" of "nascent man" for his Discourse on the Origin of Equality.)
Some modern commentators have argued that this Lucretian account of the origin life is refuted by modern science. One criticism is that Lucretius speaks mythically of Mother Earth as a teleological creator. Another criticism is that the belief in the spontaneous generation of life was refuted by Louis Pasteur's famous experiments showing that living organisms cannot arise spontaneously from lifeless material. A third criticism is that the modern fossil and archaeological record shows an evolution from simple forms of life to more complex forms, including a human fossil record showing human evolution over millions of years, which denies Lucretius's claim that all forms of life originated simultaneously and his claim that the first human beings lived as utterly solitary animals who lived on raw food without fire for cooking.
Campbell rightly defends Lucretius against the first two criticisms. But he cannot defend Lucretius against the third criticism. Against the first criticism, Campbell can point to clear statements from Lucretius that he uses teleological metaphors--like Mother Earth--to aid his anti-teleological message (2.655-60). In doing this, Lucretius is like Darwin, who explained that in personifying "survival of the fittest" as "natural selection," he was employing a metaphorical expression that was not to be interpreted literally as suggesting some intentional agency or deity (see Chapter 4 of the second edition of The Origin of Species). For Darwin, nature "selects" only in the sense that those traits that impede survival, reproduction, and competition tend to go extinct. Similarly, for Lucretius, those forms of life that cannot survive, reproduce, or compete successfully tend to go extinct. There is no teleological cosmic plan guiding this evolutionary process.
To answer the second criticism--that Pasteur refuted the belief in the spontaneous generation of life--Campbell rightly points out that while Pasteur's experiments showed that at present life cannot arise from lifeless material, this does not show that originally life could not have been spontaneously generated in the earlier conditions of the Earth. Indeed, any scientific account of the origin of life from non-life through natural evolution rather than intelligent design would have to be a spontaneous generation of life. There is today no generally accepted theory for explaining the natural origin of life, and so it remains one of the great mysteries in modern science. But there is general agreement among scientists that any successful theory for resolving this mystery will have to find a natural mechanism for the spontaneous generation of the most primitive form of life. For example, one popular theory today is that life originated from 3.2 billion to 3.8 billion years ago in very hot geothermal vents at the bottom of ancient oceans. Even if this does not prove to be the correct theory, it illustrates the search for a spontaneous generation of the first life forms like that sought by Lucretius.
Campbell does not defend Lucretius against the third criticism--that his assertion that all forms of life that we see today arose fully formed simultaneously at the beginning is contrary to the evidence for the evolutionary history of life as we know it today. Here, Campbell argues, we see why Lucretius is not truly an evolutionist in the modern Darwinian sense, because here we see that Lucretius believes in the fixity of species: although Lucretius allows for some evolutionary change within a species, he does not allow for evolutionary change by which one species evolves into another. Species can go extinct, but all of those species that have survived to the present are essentially the same species as they were at the beginning.
Although there is good evidence for this interpretation of Lucretius, there is some ambiguity here, particularly in what Lucretius says about the origins of fire and cooking (5.955-58, 1012-20, 1091-1104). Lucretius says that the first primitive human beings were tough enough to live on raw food like other animals. They had no knowledge of how to use fire for cooking. But then from observing the effects of wild fires and the warming of the Sun, they learned how to cook their food, which was part of a suite of changes that allowed them to live in family settlements that made them fully human for the first time. In his comments on this section of Lucretius's poem, Campbell observes: "Humans become truly human, and finally civilized when they have been mastered by fire, marriage, and love, and when they in turn master nature with new technologies. Fire and cooking were chief among these" (2003, 329). This shows the "process of becoming fully human" (2000, 154-55).
Doesn't this imply that those first primitive human beings who lived totally on raw food were not "truly human" at all, and so what we see here is evolution from a non-human but somewhat human-like animal species to a fully human species? If so, then this points to human evolution as inter-species evolution. Lucretius could not elaborate this idea explicitly because he did not have all of the empirical evidence available today for human evolutionary emergence from primate ancestral species.
That evidence--from fossils, archaeology, primatology, and evolutionary anthropology--confirms the truth of Lucretius's insight about the importance for human evolution of controlling fire for cooking. Richard Wrangham has surveyed this evidence in support of his "cooking hypothesis" for explaining human evolution (Wrangham 2009; Gowlett and Wrangham 2013). No human societies have ever relied on raw food for most of their diet. And no human beings have been known to survive for more than a few weeks by eating only wild raw food. Unlike every other animal, human beings need a large portion of their food to be cooked. Compared with the great apes, human beings have a reduced digestive system--small molars, mouth, stomach, and large intestine--that is adapted for digesting cooked food. Moreover, the brain is a metabolically expensive organ that requires lots of energy; and therefore the increase in the size of the brain that characterizes human evolution required a reduction in gut size and energy costs and the consumption of higher quality cooked foods to reduce the metabolic constraints on brain size by delivering increased energy to enlarged brains. The evidence of the hominin fossils indicates that Homo erectus had such enlarged brains that would have required digestive systems needing cooked food. There is also some archaeological evidence for the controlled use of fire appearing at around 1.5 million years ago, at the time of the first major increase in the brain size of early Homo. All of this evidence suggests that what Lucretius describes as a transition from primitive humans living "in a manner like wild animals" (more ferarum) (5.932) without fire and cooking to fully human beings living with fire and cooking was actually an evolutionary transformation from a pre-human species to a truly human species.
According to Campbell, "Lucretius' early humans evolve in response to their changing environment, but they are still unable to cross the species barrier imposed by the atomic laws of nature (foedera naturae); they evolve but remain within their own species" (2000, 155). Does this mean that there can be a major change in the physiology and anatomy of the digestive system without a change of species? Or should we say, in the terminology of modern taxonomy, that there has been a change of species but not of genus?
Campbell says that the evolution here in Lucretius is not Darwinian evolution but Lamarckian evolution, because it's the evolution of acquired characters. Contrary to what Campbell assumes, Darwin accepted Lamarckian evolution. Today, some evolutionary theorists would say that there are at least four levels of evolutionary inheritance--genetic, epigenetic, behavioral, and symbolic (Jablonka and Lamb 2014). Could we explain what Lucretius describes here as genetic/behavioral coevolution?
Oddly, while Campbell argues that Lucretius was not a Darwinian evolutionist, he also argues that Lucretius was a better evolutionist than was Darwin! This is my third point of disagreement with Campbell. According to Campbell, Lucretius suggests that evolutionary adaptation in the struggle for life can occur at five levels--survival, reproduction, competition, competition avoidance, and cooperation. Campbell thinks that Darwin recognizes the first three levels but not the last two (Campbell 2003, 119-23, 129, 252-61). I disagree. Lucretius claims that human beings could not have survived if they had not learned to cooperate: "It was then that neighbors, in their eagerness neither to harm nor be harmed, began to form mutual pacts of friendship, and claimed protection for their children and women, indicating by means of inarticulate cries and gestures that everyone ought to have compassion for the weak" (5.1019-23).
Campbell sees this idea as confirmed by recent work (by Robert Axelrod and others) on the evolution of cooperation, but he does not see this idea was first elaborated by Darwin in his account of the evolution of the "moral sense" in The Descent of Man. All of the recent thinking about the evolution of cooperation through kin selection, reciprocity (direct and indirect), and group selection is building on Darwin's thinking in Descent.
Lucretius also recognizes the human domestication of animals as mutually beneficial for the animals and human beings (5.862-78). Campbell identifies this as "extinction avoidance through symbiosis and the survival advantages of becoming tame" (2003, 129). This also was well studied by Darwin, particularly in his Variation of Animals and Plants Under Domestication (1868).
My final point of disagreement with Campbell concerns his understanding of teleology. He is right in seeing that modern Darwinian biology agrees with Lucretius and the Epicureans in their anti-teleological view of the cosmos as a spontaneous order that has not been designed to serve any purpose. But only obliquely does Campbell recognize that modern biology can affirm immanent teleology while denying cosmic teleology (Campbell 2000, 152, 170-71). Although the evolutionary process does not serve goals, the organisms emerging from that process do. Reproduction, growth, feeding, healing, courtship, parental care for offspring--these and many other activities of organisms are goal directed. Biologists cannot explain such phenomena unless they ask about ends or purposes immanent in the evolved nature of the species. This allows for a biological understanding of morality as natural right or natural law rooted in the immanent teleology of evolved human nature.
REFERENCES
Campbell, Gordon. 2000. "Zoogony and Evolution in Plato's Timaeus: The Presocratics, Lucretius, and Darwin." In M. R. Wright, ed., Reason and Necessity: Essays on Plato's Timaeus, 145-80. Swansea, UK: The Classical Press of Wales.
Campbell, Gordon. 2003. Lucretius on Creation and Evolution: A Commentary on De Rerum Natura, Book Five, Lines 772-1104. Oxford: Oxford University Press.
Gowlett, John A. J., and Richard W. Wrangham. 2013. "Earliest Fire in Africa: Towards the Convergence of Archaeological Evidence and the Cooking Hypothesis." Azania: Archaeological Research in Africa 48: 5-30.
Jablonka, Eva, and Marion J. Lamb. 2014. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Revised edition. Cambridge: MIT Press.
Wrangham, Richard W. 2009. Catching Fire: How Cooking Made Us Human. New York: Basic Books.
Some of these points are elaborated in other posts here, here, here, here, here, here, here, here, here, here, here, here, here, here., and here.
Today, this debate is between the creationists or intelligent design theorists, on the one side, and the Darwinian evolutionists, on the other side. Some theistic evolutionists (like Francis Collins or Owen Gingerich, for example) have tried to take a third position: that the Creator has designed the parameters of certain natural constants so that cosmic evolution is fine-tuned for producing intelligent human life as the fulfillment of the Creator's purposes.
In ancient Greece, some of the pre-Socratic natural philosophers (like Empedocles and Democritus) developed materialist or mechanist explanations for how the world and all living beings in it could have emerged by natural causes without any divine design or purpose. In some of Plato's dialogues--particularly in book 10 of the Laws and in the Timaeus--this anti-teleological cosmology was rejected as a dangerous atheism that would subvert the moral and political order of human life. Plato's Athenian Stranger (in the Laws) argues that everyone in the political order he proposes must believe that the gods exist, that the gods think about and care for human beings, and that the gods enforce justice by rewarding the good and punishing the bad. Those people who openly question this cosmic theology should be imprisoned, and if they cannot be persuaded to accept this theology, they will be punished with death. Plato's Timaeus argued that people should be taught that everything was created by a divine Demiurge or Craftsman assisted by other gods according to a model of an eternally enduring nature, so that the cosmos could be seen as the best of all possible worlds.
Later, Epicurus challenged this Platonic cosmic teleology by developing his own anti-teleological cosmology based on the atomistic science of Democritus. Everything could be understood as the patterns of order arising from the combining and dissolving of atoms moving in a void, so that all possible combinations of these atoms would arise as worlds coming into being and passing away. All life is mortal, so there is no afterlife, and no divine judgment of human beings after death. The gods exist, but they live outside the world of human experience, and they do not care for or intervene in human affairs. All of the organized religions that teach that the gods have created the world and judge human beings both in this life and in the afterlife deprive human beings of happiness by promoting a fear of death and of divine judgment that creates unnecessary and unreasonable anxiety.
Epicureans can be happy because they don't fear god, they don't worry about death, they know that the goodness of pleasure is usually easy to get, and they know that the badness of pain is usually easy to endure. This is possible because their freedom from religious fears and their understanding of how everything is ultimately explained by natural causes allows them to live out their mortal lives with tranquil minds.
Although Epicurus wrote many books, most of his writing has been lost, and we now have only fragments quoted by other writers. The most extensive text of Epicurean philosophy is the Latin philosophical poem of Lucretius--De Rerum Natura (On the Nature of Things)--which he wrote sometime before his death in 55 B.C. Although he does not mention Plato by name, Lucretius can be seen as defending the Epicurean anti-teleological cosmology against the Platonic teleological cosmology, particularly as it was reformulated by the Stoics.
Christian theologians were able to accept modified forms of the Platonic and Stoic cosmology of divine creation as compatible with Biblical creationist theology, which became the predominant model of the cosmos in Christendom for over 1,500 years. But Christians had to scorn the Epicurean/Lucretian cosmology of materialist atomism as promoting a dangerously atheistic view of the universe.
The texts of Lucretius' book were either destroyed or hidden away, until a text was rediscovered in 1417 by Poggio Bracciolini. Many early modern philosophers and scientists could then see the Lucretian materialist and anti-teleological model of the cosmos as the alternative to the creationist and teleological model of Christian cosmology.
Finally, with the publication in 1859 of Charles Darwin's On the Origin of the Species, the Darwinian theory of the evolution of species by natural selection in the struggle for survival seemed to provide a modern scientific version of Lucretian cosmology as an alternative to Christian creationism. If so, then the debate between evolutionists and creationists today continues the debate between Platonists and Epicureans over whether the cosmos has been intelligently and purposefully designed or not.
As I have indicated in some previous posts, this cosmological debate is also a moral and political debate, because while the Platonic/Christian cosmology of order as a top-down imposition of intentional planning seems to support moral and political authoritarianism, the Epicurean/Darwinian cosmology of order as a bottom-up emergence of spontaneous order seems to support moral and political liberalism.
But is it really true that the Epicurean cosmology of Lurcretius' book conforms to a Darwinian evolutionary conception of the universe? Gordon Campbell (a classics scholar) has helped me to think about this through one of his papers--"Zoogony and Evolution in Plato's Timaeus: The Presocratics, Lucretius, and Darwin" (2000)--and one of his books--Lucretius on Creation and Evolution (2003). Campbell's writing illuminates Lucretius' place in the evolution/creation debate from ancient Greece to the present.
And yet I do disagree with Campbell on four points. First, I disagree with his claim that the only "fully evolutionary theory" of the cosmos in the ancient world is in Plato's Timaeus (Campbell 2003, 2). He distinguishes between two kinds of evolution (Campbell 2000, 14). "Inter-specific evolution" is "the Darwinian model of the origin of species by the gradual accumulation of variation over time leading to the formation of new species." "Intra-specific evolution" is "the accumulation of variation within a species that stops short of crossing species boundaries." He claims that Plato is the only ancient proponent of Darwinian inter-specific evolution, because Plato's Timaeus describes an evolutionary process in which the Demiurge first creates human beings and then morally degenerate human beings evolve into four kinds of animals--birds, footed land animals, footless land animals, and fish--with the animals ranked from the more thoughtful animals to the thoughtless animals.
The first problem with Campbell's claim is that what Timaeus describes is not a natural evolutionary process at all, because he asserts it to be the work of divine creation by the Demiurge and the other gods (Timaeus 41a-d, 92c).
The second problem is that it's not clear that Plato or Plato's Socrates endorses Timaeus's story of cosmic creation. Timaeus's story is so utterly ridiculous that many readers have doubted that Plato takes it seriously. A. E. Taylor, for example, made this point, but Campbell casually dismisses this and insists that Timaeus's story must be seen as a serious teaching of Plato (2000, 158). But Campbell doesn't explain the many strange features of this dialogue. First of all, it's not much of a dialogue. After some brief exchanges between Socrates and Timaeus, Timaeus launches into a long lecture that takes up most of the book. Socrates remains silent, which suggests that Timaeus's story cannot withstand any Socratic questioning. Timaeus says that his story will be a "likely myth." Socrates says that it will be a nomos--a song, a custom, or a law (Timaeus 29d). So Timaeus's story is not a reasoned account of the cosmos.
Moreover, what Timaeus says is often self-contradictory. For example, Timaeus says that the best account of astronomy depends on sight--looking at the stars and the Sun--and this shows the primacy of our eyes for our knowledge of the world (47a-c). But then he condemns as "light-minded" the empirical astronomers who believe that our knowledge of astronomy must begin with what we can see with our own eyes. Such people are punished by being turned into birds (91d-e).
My point here is that Campbell does not consider the possibility that while Plato might have thought that a teleological cosmology of divinely intelligent design could be a salutary belief for many people, it could not be a rational account of the cosmos for natural philosophers. Aristotle suggested this in observing that such cosmic myths were little more than traditional folk tales (On the Heavens, 270b1-25, 283b26-284b5, 291b24-292a20, 298b6-299a2; The Movement of Animals, 699b12-31; Metaphysics, 1050b20-25, 1074b1-14).
Not only do I think Campbell is wrong in identifying Plato as an evolutionist, I also think he is wrong in denying that Lucretius was an evolutionist. This is my second point of disagreement. Although Campbell is right in noting that Lucretius never explicitly affirms the "inter-specific evolution" of a new species from an ancestral species, Lucretius does at least implicitly suggest that human beings have evolved from an earlier species that was human-like but not fully human, because it did not have the human digestive system that requires food cooked with fire. Lucretius could not explicitly elaborate this idea, because he lacked the evidence for human evolution that is available today--including the fossil record, the archaeological record, human physiology, and comparative primatology.
In Book 5 of De Rerum Natura, Lucretius explains the origin of all living beings as the spontaneous generation of life from the Earth (5.785-1012). Just as today we can see the spontaneous generation of worms and cicadas from the Earth, Lucretius claims, we can imagine that at the beginning the Earth was so fertile that it could generate all forms of plant and animal life (2.871-72, 898-901, 928-29, 3.719-36, 5.797-98). For this reason, Lucretius observes, the Earth has rightly been called the Mother of all life.
At first, the Earth experimented with many monstrous animal bodies with grotesque appearance--such as animals that were both male and female, animals without feet or hands or mouths. These forms of life "were created in vain," because nature extinguished them. They died from starvation. Or they could not reproduce. Or they could not compete with other animals. Only those species adapted for survival, reproduction, and competition were naturally selected for preservation. Those human beings who lived in these early days were tougher and larger than human beings today. They lived as solitary foragers and like savage beasts, with no families, no farming, no customs or laws, no use of fire or clothing. Men and women came together for sexual copulation and then separated with no enduring attachment. (Here is where Rousseau found his first "state of nature" of "nascent man" for his Discourse on the Origin of Equality.)
Some modern commentators have argued that this Lucretian account of the origin life is refuted by modern science. One criticism is that Lucretius speaks mythically of Mother Earth as a teleological creator. Another criticism is that the belief in the spontaneous generation of life was refuted by Louis Pasteur's famous experiments showing that living organisms cannot arise spontaneously from lifeless material. A third criticism is that the modern fossil and archaeological record shows an evolution from simple forms of life to more complex forms, including a human fossil record showing human evolution over millions of years, which denies Lucretius's claim that all forms of life originated simultaneously and his claim that the first human beings lived as utterly solitary animals who lived on raw food without fire for cooking.
Campbell rightly defends Lucretius against the first two criticisms. But he cannot defend Lucretius against the third criticism. Against the first criticism, Campbell can point to clear statements from Lucretius that he uses teleological metaphors--like Mother Earth--to aid his anti-teleological message (2.655-60). In doing this, Lucretius is like Darwin, who explained that in personifying "survival of the fittest" as "natural selection," he was employing a metaphorical expression that was not to be interpreted literally as suggesting some intentional agency or deity (see Chapter 4 of the second edition of The Origin of Species). For Darwin, nature "selects" only in the sense that those traits that impede survival, reproduction, and competition tend to go extinct. Similarly, for Lucretius, those forms of life that cannot survive, reproduce, or compete successfully tend to go extinct. There is no teleological cosmic plan guiding this evolutionary process.
To answer the second criticism--that Pasteur refuted the belief in the spontaneous generation of life--Campbell rightly points out that while Pasteur's experiments showed that at present life cannot arise from lifeless material, this does not show that originally life could not have been spontaneously generated in the earlier conditions of the Earth. Indeed, any scientific account of the origin of life from non-life through natural evolution rather than intelligent design would have to be a spontaneous generation of life. There is today no generally accepted theory for explaining the natural origin of life, and so it remains one of the great mysteries in modern science. But there is general agreement among scientists that any successful theory for resolving this mystery will have to find a natural mechanism for the spontaneous generation of the most primitive form of life. For example, one popular theory today is that life originated from 3.2 billion to 3.8 billion years ago in very hot geothermal vents at the bottom of ancient oceans. Even if this does not prove to be the correct theory, it illustrates the search for a spontaneous generation of the first life forms like that sought by Lucretius.
Campbell does not defend Lucretius against the third criticism--that his assertion that all forms of life that we see today arose fully formed simultaneously at the beginning is contrary to the evidence for the evolutionary history of life as we know it today. Here, Campbell argues, we see why Lucretius is not truly an evolutionist in the modern Darwinian sense, because here we see that Lucretius believes in the fixity of species: although Lucretius allows for some evolutionary change within a species, he does not allow for evolutionary change by which one species evolves into another. Species can go extinct, but all of those species that have survived to the present are essentially the same species as they were at the beginning.
Although there is good evidence for this interpretation of Lucretius, there is some ambiguity here, particularly in what Lucretius says about the origins of fire and cooking (5.955-58, 1012-20, 1091-1104). Lucretius says that the first primitive human beings were tough enough to live on raw food like other animals. They had no knowledge of how to use fire for cooking. But then from observing the effects of wild fires and the warming of the Sun, they learned how to cook their food, which was part of a suite of changes that allowed them to live in family settlements that made them fully human for the first time. In his comments on this section of Lucretius's poem, Campbell observes: "Humans become truly human, and finally civilized when they have been mastered by fire, marriage, and love, and when they in turn master nature with new technologies. Fire and cooking were chief among these" (2003, 329). This shows the "process of becoming fully human" (2000, 154-55).
Doesn't this imply that those first primitive human beings who lived totally on raw food were not "truly human" at all, and so what we see here is evolution from a non-human but somewhat human-like animal species to a fully human species? If so, then this points to human evolution as inter-species evolution. Lucretius could not elaborate this idea explicitly because he did not have all of the empirical evidence available today for human evolutionary emergence from primate ancestral species.
That evidence--from fossils, archaeology, primatology, and evolutionary anthropology--confirms the truth of Lucretius's insight about the importance for human evolution of controlling fire for cooking. Richard Wrangham has surveyed this evidence in support of his "cooking hypothesis" for explaining human evolution (Wrangham 2009; Gowlett and Wrangham 2013). No human societies have ever relied on raw food for most of their diet. And no human beings have been known to survive for more than a few weeks by eating only wild raw food. Unlike every other animal, human beings need a large portion of their food to be cooked. Compared with the great apes, human beings have a reduced digestive system--small molars, mouth, stomach, and large intestine--that is adapted for digesting cooked food. Moreover, the brain is a metabolically expensive organ that requires lots of energy; and therefore the increase in the size of the brain that characterizes human evolution required a reduction in gut size and energy costs and the consumption of higher quality cooked foods to reduce the metabolic constraints on brain size by delivering increased energy to enlarged brains. The evidence of the hominin fossils indicates that Homo erectus had such enlarged brains that would have required digestive systems needing cooked food. There is also some archaeological evidence for the controlled use of fire appearing at around 1.5 million years ago, at the time of the first major increase in the brain size of early Homo. All of this evidence suggests that what Lucretius describes as a transition from primitive humans living "in a manner like wild animals" (more ferarum) (5.932) without fire and cooking to fully human beings living with fire and cooking was actually an evolutionary transformation from a pre-human species to a truly human species.
According to Campbell, "Lucretius' early humans evolve in response to their changing environment, but they are still unable to cross the species barrier imposed by the atomic laws of nature (foedera naturae); they evolve but remain within their own species" (2000, 155). Does this mean that there can be a major change in the physiology and anatomy of the digestive system without a change of species? Or should we say, in the terminology of modern taxonomy, that there has been a change of species but not of genus?
Campbell says that the evolution here in Lucretius is not Darwinian evolution but Lamarckian evolution, because it's the evolution of acquired characters. Contrary to what Campbell assumes, Darwin accepted Lamarckian evolution. Today, some evolutionary theorists would say that there are at least four levels of evolutionary inheritance--genetic, epigenetic, behavioral, and symbolic (Jablonka and Lamb 2014). Could we explain what Lucretius describes here as genetic/behavioral coevolution?
Oddly, while Campbell argues that Lucretius was not a Darwinian evolutionist, he also argues that Lucretius was a better evolutionist than was Darwin! This is my third point of disagreement with Campbell. According to Campbell, Lucretius suggests that evolutionary adaptation in the struggle for life can occur at five levels--survival, reproduction, competition, competition avoidance, and cooperation. Campbell thinks that Darwin recognizes the first three levels but not the last two (Campbell 2003, 119-23, 129, 252-61). I disagree. Lucretius claims that human beings could not have survived if they had not learned to cooperate: "It was then that neighbors, in their eagerness neither to harm nor be harmed, began to form mutual pacts of friendship, and claimed protection for their children and women, indicating by means of inarticulate cries and gestures that everyone ought to have compassion for the weak" (5.1019-23).
Campbell sees this idea as confirmed by recent work (by Robert Axelrod and others) on the evolution of cooperation, but he does not see this idea was first elaborated by Darwin in his account of the evolution of the "moral sense" in The Descent of Man. All of the recent thinking about the evolution of cooperation through kin selection, reciprocity (direct and indirect), and group selection is building on Darwin's thinking in Descent.
Lucretius also recognizes the human domestication of animals as mutually beneficial for the animals and human beings (5.862-78). Campbell identifies this as "extinction avoidance through symbiosis and the survival advantages of becoming tame" (2003, 129). This also was well studied by Darwin, particularly in his Variation of Animals and Plants Under Domestication (1868).
My final point of disagreement with Campbell concerns his understanding of teleology. He is right in seeing that modern Darwinian biology agrees with Lucretius and the Epicureans in their anti-teleological view of the cosmos as a spontaneous order that has not been designed to serve any purpose. But only obliquely does Campbell recognize that modern biology can affirm immanent teleology while denying cosmic teleology (Campbell 2000, 152, 170-71). Although the evolutionary process does not serve goals, the organisms emerging from that process do. Reproduction, growth, feeding, healing, courtship, parental care for offspring--these and many other activities of organisms are goal directed. Biologists cannot explain such phenomena unless they ask about ends or purposes immanent in the evolved nature of the species. This allows for a biological understanding of morality as natural right or natural law rooted in the immanent teleology of evolved human nature.
REFERENCES
Campbell, Gordon. 2000. "Zoogony and Evolution in Plato's Timaeus: The Presocratics, Lucretius, and Darwin." In M. R. Wright, ed., Reason and Necessity: Essays on Plato's Timaeus, 145-80. Swansea, UK: The Classical Press of Wales.
Campbell, Gordon. 2003. Lucretius on Creation and Evolution: A Commentary on De Rerum Natura, Book Five, Lines 772-1104. Oxford: Oxford University Press.
Gowlett, John A. J., and Richard W. Wrangham. 2013. "Earliest Fire in Africa: Towards the Convergence of Archaeological Evidence and the Cooking Hypothesis." Azania: Archaeological Research in Africa 48: 5-30.
Jablonka, Eva, and Marion J. Lamb. 2014. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Revised edition. Cambridge: MIT Press.
Wrangham, Richard W. 2009. Catching Fire: How Cooking Made Us Human. New York: Basic Books.
Some of these points are elaborated in other posts here, here, here, here, here, here, here, here, here, here, here, here, here, here., and here.
Friday, December 14, 2018
Flies Are Cultural Conformists in Their Sexual Preferences: The Biology of Cultural and Biographical History
Fruitflies Show Social Learning of Mating Preferences
Unlike Hobbes, Aristotle saw no unbridgeable gulf between animal instinct and human learning. In his biological research, he observed that almost all animals have some natural instincts for social learning, and some are intelligent enough to live as social and political animals. What distinguishes human beings is that they are more political than other political animals because of the human capacities for language, conceptual abstraction, and shared intentionality that allow human beings to organize their collective life around shared symbolic norms of authority and justice.
Over the past two hundred years, it has been common for scholars to assume that Hobbes was right in claiming that human beings are unique in being the only cultural animals, and therefore that the "human sciences" (Geisteswissenschaften) as the study of cultural history must be separated from the "natural sciences" (Naturwissenschaften) as the study of natural phenomena. If this is so, then the evolutionary biology of human nature has no application to human social and political life.
But over the past fifty years, evolutionary scientists have gathered ever increasing evidence--from both observational and experimental studies of animal behavior--that many animal species show social learning and cultural traditions, and therefore Aristotle was right.
CULTURAL FLIES
Recently, for example, researchers have shown that even fruitflies are cultural animals (Danchin et al. 2018; Whiten 2018). Female fruitflies tend to conform to the mating preferences they observe in other females, which generates cultural traditions that are passed on to others through social learning. The researchers placed virgin female fruitflies in a hexagonal chamber, surrounded by six compartments in each of which they could see a female fly mating with a male dusted by either pink or green coloring, with another male of the alternative color standing nearby. Some females saw that all six of the mating males were pink. Others saw that all were green. Others saw different proportions of pink versus green males mating.
Two Females Watch a Copulating Green Male, While a Pink Male Is Rejected
So now fruitflies are added to a long and growing list of animals identified by scientists today as showing cultural behavior. The list includes many mammalian, avian, fish, and insect species (Galef and Whiten 2017; Whiten et al. 2017). Actually, however, this is only a rediscovery of what Aristotle reported long ago in his biological writings.
GENE-CULTURE COEVOLUTION
The advance beyond Aristotle has been in developing an evolutionary science of animal culture based on Charles Darwin's theory. Darwin understood that his principles of organic evolution--variation, selection, and inheritance--could be applied to cultural evolution, such as the cultural evolution of languages (Mesoudi, Whiten, and Laland 2004). Darwin did not understand, however, the genetic mechanisms of organic evolution. With their modern understanding of genetics, evolutionary scientists today see genes and culture as two distinct forms of evolutionary inheritance. Some evolutionary theorists argue that there are really four dimensions of evolution: genetic inheritance, epigenetic inheritance, behavioral inheritance, and symbolic inheritance (Jablonka and Lamb 2014).
Evolutionary science needs to explain the complex interaction of these systems of inheritance. This is hard to do, as indicated by the recent work on gene-culture coevolution. It's hard to define and identity the units of culture. Richard Dawkins suggested that we might speak of cultural "memes" as analogous to organic "genes," but there is little agreement as to what should count as memes.
It's also hard to discern the connections between genes and memes, because little is known about how exactly genes influence behavior, or how exactly behavior might influence gene expression and transmission.
There are only a few examples of well-understood gene-culture coevolution. One of the most famous cases is the evolution of lactase persistence. The production of the enzyme lactase in the gut is necessary for the digestion of the milk sugar lactose. This enzyme is produced in human infants so that they can digest the lactose in their mother's milk. But in most human adults, the production of lactase is shut down, and so they suffer severe indigestion from the consumption of milk. And yet lactase persistence--the production of lactase in adulthood--is common among those human beings with a northern and western European ancestry and those from some pastoralist groups in Africa, the Middle East, and southern Asia. The likely explanation for this is that lactase persistence evolved among dairying farmers around 7,500 years ago as a genetic adaptation to dairying culture (Itan et al. 2009). Geneticists have identified a particular genetic variation that supports lactase persistence, and they can see that this genetic variation correlates with the cultural evolution of dairying. So here is a clear case of where a cultural tradition created an environment that favored genetic change that would be adaptive.
It's unfortunate that Darwin did not understand this, because the mysterious intestinal illness from which he suffered throughout his life was probably a result of his being lactose intolerant. Medical researchers studying Darwin's records of his illness have noticed that it always arose a few hours after eating dairy foods (Campbell and Matthews 2005). All of his symptoms--vomiting, gut pain, headaches, tiredness, and depression--match the effects of lactose intolerance.
There are very few studies of nonhuman animal culture that can show this same clarity in the mechanism of gene-culture evolution. One case that comes close is the study of animal culture among the killer whales or orcas. Orcas stretch from the Arctic to the Antarctic, and they diets range over birds, fish, mammals, and reptiles. But as individuals, they belong to groups with different specialized diets and hunting traditions that are passed down over generations. These groups also show variations in their cultural traditions for vocal displays, habitat use, play, and migration routes. Some of the scientists studying them have seen stable genetic variation in each group that correlates with their cultural traditions, which suggests gene-culture coevolution (Foote et al. 2016; Whitehead 2017).
BIOLOGY INCLUDES CULTURAL HISTORY AND BIOGRAPHICAL HISTORY
Notice how this recognition of animal culture expands the range of biology to include cultural history and biographical history. The biological study of animal behavior must go beyond the natural history of a species--the universal species-specific patterns of behavior--to include the distinctive cultural history of each group of animals.
Moreover, the study of animal culture shows that cultural traditions originate from innovations initiated by particular individuals that have been so successful that they have been passed on by social learning to other individuals and to subsequent generations. Consequently, the study of animal behavior must include the study of the individual personalities of the animals responsible for cultural innovations. For example, scientists have observed that among wild capuchin monkeys some individuals are better than others at social invention and innovation (Perry et al. 2017). In fact, most of the detailed histories of particular animal groups--such as Jane Goodall's The Chimpanzees of Gombe--include biographical histories of the individual animals that have shaped the history of the group.
This supports my argument that a biopolitical science would have to move through three levels of political history--the natural history of the species, the cultural history of the group, and the biographical history of prominent individuals in the group.
Some of these points are elaborated in other posts here, here, here, here, here, here, and here,
REFERENCES
Campbell, Anthony, and Stephanie B. Matthews. 2005. "Darwin's Illness Revealed." Postgraduate Medical Journal 81: 248-51.
Danchin, Etienne, et al. 2018. "Cultural Flies: Conformist Social Leaning in Fruitflies Predicts Long-Lasting Mate-Choice Traditions." Science 362: 1025-1030.
Foote, Andrew D. et al. 2016. "Genome-Culture Coevolution Promotes Rapid Divergence of Killer Whale Ecotypes." Nature Communications 7:11693.
Galef, Bennett G., and Andrew Whiten. 2017. "The Comparative Psychology of Social Learning." In Joseph Call, et al., eds., APA Handbook of Comparative Psychology, 411-439. Washington, DC: American Psychological Association.
Itan, Yuval, et al. 2009. "The Origins of Lactase Persistence in Europe." PLoS Computational Biology 5 (8): e1000491.
Jablonka, Eva, and Marion Lamb. 2014. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Revised ed. Cambridge: MIT Press.
Mesoudi, Alex, Andrew Whiten, and Kevin N. Laland. 2004. "Is Human Cultural Evolution Darwinian? Evidence Reviewed From the Perspective of The Origin of Species." Evolution 58 (1): 1-11.
Perry, Susan E., Brendan J. Barrett, and Irene Godoy. 2017. "Older, Sociable Capuchins (Cebus caucinus) Invent More Social Behaviors, But Younger Monkeys Innovate More in Other Contexts." Proceedings of the National Academy of Sciences 114 (30): 7806-7813.
Whitehead, Hal. 2017. "Gene-Culture Coevolution in Whales and Dolphins." Proceedings of the National Academy of Sciences 114 (30): 7814-7821.
Whiten, Andrew. 2018. "Culture and Conformity Shape Fruitfly Mating." Science 362: 998-1000.
Whiten, Andrew. et al. 2017. "The Extension of Biology Through Culture." Proceedings of the National Academy of Sciences 114 (30): 7775-7781.
Saturday, August 20, 2016
Deirdre McCloskey and the Evolutionary Science of Liberalism as Symbolic Niche Construction
The most momentous event in the evolutionary history of Homo sapiens over the past 200,000 years was the emergence of the Bourgeois Era through the Industrial Revolution (beginning around 1800) followed by the Great Enrichment (beginning around 1860). The only other equally momentous event was the emergence of the Agrarian Era, when human beings moved from foraging (hunting wild animals and gathering wild plants) to farming (herding domesticated animals and cultivating domesticated plants), which began about 10,000 years ago.
We all recognize the importance of the Industrial Revolution, but few of us recognize that economic historians have uncovered other industrial revolutions at other times and places in history. Those other industrial revolutions did not bring a Great Enrichment--the explosive growth in wealth sustaining an explosive growth in population over the past two centuries, beginning in northwestern Europe and then spreading around the world. One of the deepest questions for all of the intellectual disciplines--the natural sciences, the social sciences, and the humanities--is how to explain why this has happened. Or, in other words, why is our world in the Bourgeois Era so very different from the world of all of our ancestors?
Bourgeois Equality (2016) is the third big book in a trilogy of big books that Deirdre McCloskey has written to answer this question. The previous two are The Bourgeois Virtues (2006) and Bourgeois Dignity (2010). All three books elaborate arguments that were first set forth in 1994 in an article--"Bourgeois Virtue"--in the American Scholar, written by Donald McCloskey before he became Deirdre. Every main idea, and sometimes even the exact wording, in the books comes from the article.
The plan for this intellectual project came to McCloskey while she was on an airplane and reading John Casey's book Pagan Virtue (1990). As suggested by Friedrich Nietzsche, Casey contrasts the pagan aristocratic virtues of Achilles, for whom courage is the primary virtue, and the plebeian Christian virtues of Saint Paul, for whom charity is the primary virtue. Today, McCloskey thought, most of us are bourgeois, and we are neither pagan aristocrats nor Christian plebeians. We are neither heroes nor saints. What are our bourgeois virtues? Or must we admit, as Gustav Flaubert and other bohemian critics of the bourgeois have declared, that the only way for the bourgeois to become good is to stop being bourgeois? Bourgeois liberalism has allowed more human beings to enjoy individual liberty, equal dignity, and economic prosperity than ever before in the history of the world. Prior to 1800, most people everywhere lived in grinding poverty. Now, few people live in such poverty. Surely, there must be something good in that, something virtuous.
The greatness of the Great Enrichment is evident in the economic data. McCloskey summarizes some of the data from economic historians (like Angus Maddison) and from the World Bank, the International Monetary Fund, and the Penn Tables (put together by scholars at the University of Pennsylvania) (Bourgeois Equality, 5-13). Expressed in present-day U.S. prices, corrected for exchange rates and inflation, the average human being prior to 1800 lived on $3 a day, which is the average today for Haitians and Afghans. Today, the world average, which includes the poorest people like the Haitians and Afghans, is $33 a day, which is about the level of present-day Brazil or of the United States in 1941. So average per person income has increased over the past two centuries by a favor of 10. And since the world population has increased over that same period from under one billion to over seven billion, we can say that the production and consumption of goods and services has increased worldwide by a factor of 70 (7 X 10). In the wealthier countries today, the average real income per person per day is well over $100, which means an income growth from 1800 to the present of 2,900%.
Prior to 1800, periods of increasing economic growth could double or triple average daily income--from $3 a day to $6 or $9 a day--but inevitably these periods of growth were followed by a decline back to subsistence levels. So, prior to 1800, real income per person could increase by 100% or 200% in times of great economic growth, but never by 2,900%, as has happened in the past two centuries.
McCloskey contends that the greatest transformation in human history was not the 450 years of sustained economic growth in England, 1348-1750, at a growth rate of one-tenth or two-tenths of 1 percent per year. And it was not the Industrial Revolution in Great Britain, 1760-1860, with growth over a hundred years of a factor of 2. The great transformation was the Great Enrichment, with growth of 5.87% per year and a factor of 100 over two centuries (BE, 532). There had been major growth phases in earlier history elsewhere in the world--early Song China and early Tokugawa Japan, for example--but these were periods in which growth rose by factors of 2 or 3, not factors of 10 or 30 or 100 (BE, 534-35).
Moreover, other measures of improving human conditions of life show the same Great Enrichment. Average life expectancies have doubled since 1800, for example, and literacy has increased from less than 10% in 1850 to almost 90% today. The increase in literacy indicates not just material enrichment, but also intellectual and spiritual enrichment.
Social scientists have offered many different kinds of explanations for this unprecedented turn in human history, beginning first in northwestern Europe and North America, and then spreading around the world. One explanation popular with many economists (such as Douglass North, Daron Acemoglu, and James Robinson) emphasizes the importance of economic, legal, and political institutions that favor economic growth--particularly, property rights, the rule of law, free trade, and general incorporation laws for forming economic corporations, which provided the incentives for economic exchange and innovation.
But while such institutional rules are necessary conditions for economic growth, McCloskey argues, they are hardly sufficient to explain the historically unique explosion in economic development that began after 1800. Good institutions are necessary, but only quick changes in good ideas can explain the quick move to the Great Enrichment. Ideas matter, McCloskey insists, particularly ethical ideas about the bourgeois life. What changed in the eighteenth century in Great Britain (preceded by the same change in the seventeenth century in the Dutch Republic) was that for the first time in human history the bourgeois life of trade-tested betterment--buying low and selling high--was judged not as morally corrupting, as it had been throughout history, but as morally virtuous and thus honorable.
For hundreds of thousands of years, human beings have expressed the bourgeois "propensity to truck, barter, and exchange," which has fostered economic growth. But it was not until the seventeenth and eighteenth centuries in northwestern Europe that philosophers like Adam Smith defended this as a virtuous activity that should be admired as protected by a system of natural liberty that would recognize the equal liberty and dignity of ordinary people in living their lives as they please. This change in the ethical rhetoric of ideas brought the Great Enrichment of the nineteenth century. This change was the move to liberalism, to Smith's liberal idea for "allowing every man to pursue his own interest his own way, upon the liberal plan of equality, liberty, and justice" (Wealth of Nations, Liberty Fund, 664, 687).
The institutions of property rights, the rule of law, and free trade can be found in many civilizations throughout human history. For example, as McCloskey points out, Genghis Khan's Pax Mongolia of the thirteenth century enforced property rights and the rule of law over a land empire stretching from Korea to Hungary, which protected global free trade throughout Central Asia. China had private property, extensive markets, and large firms many centuries before England had such institutions. Even ancient Mesopotamia had property rights and trade protected by law four thousand years ago. What all of these countries lacked, however, was the bourgeois ethics of Smithian liberalism that led to the Great Enrichment beginning in nineteenth century Great Britain.
Institutions without ideas are not enough to explain this. In fact, as McCloskey points out (BE, 518), even institutionalists like North will occasionally admit this. In Violence and Social Orders (2009) by North, John Wallis, and Barry Weingast, there is one passage (pp. 192-93) where the authors must fall back on ideational explanation for the transition to "open access societies": they speak of a "transformation in thinking," a "new understanding," "the language of rights," and "the logic of the argument." But then they fail to reflect on how this points to the primacy of liberal ideas advanced by people like John Locke and Adam Smith.
If McCloskey is right about the rhetorical appeal of liberal ideas promoting bourgeois ethics, as I think she is, then we must wonder what it is about evolved human nature that makes such ideas rhetorically appealing. Generally, McCloskey scorns evolutionary science in explaining social and economic history, because she fears that this falls into a crude social Darwinism, scientific racism, and eugenic materialism, which she sees, for example, in Gregory Clark's explanation of the British Industrial Revolution as arising from "survival of the richest" (Bourgeois Dignity, 266-95).
McCloskey also says, however, that her argument can be put into "evolutionary terms," because "I am arguing that the meme 'trade-tested-betterments are good' had reproductive success, and further, that on the success of the idea depended the material success of the modern world" (BE, 521-22). This would be a case of cultural evolution, of the sort studied by evolutionary scientists like Robert Boyd, Peter Richerson, and Joseph Henrich. Eva Jablonka and Marion Lamb have shown that in evolutionary history there are four systems of inheritance: genetic, epigenetic, behavioral, and symbolic. Of these four, the first three are manifest among nonhuman animals. Symbolic evolution is the one uniquely human line of evolutionary inheritance, which includes the whole realm of conceptual ideas and rhetorical persuasion. What McCloskey identifies as the Bourgeois Revaluation in liberalism belongs to human symbolic evolution.
McCloskey (BE, 631-39) also embraces an evolutionary theory of liberalism set forth in a paper by Gerald Gaus (2015), who relies largely on ideas developed by Christopher Boehm (1999, 2012) and by Richerson and Boyd (2008). This is the same evolutionary account of liberalism that has been defended by Jonathan Turner, Alexandra Maryanski, Paul Rubin, and me (in various writings as well as on this blog).
The basic idea, as McCloskey says, is that bourgeois liberalism is "reinstating a pre-agricultural equality" by establishing an equal dignity and liberty for ordinary people--including an "equality of genuine comfort"--that restores the equal autonomy of individuals enjoyed in hunter-gatherer bands for hundreds of thousands of years until the establishment of rigid class hierarchies in agrarian societies.
As I have argued in some earlier posts, this is a restatement of John Locke's argument for liberalism as the restoration of the natural liberty and equality that hunter-gatherers had in the "state of nature." Locke's account of the state of nature depended on the reports of Europeans about the foraging life of native Americans. "In the beginning," Locke declared, "all the world was America." Now, after two centuries of scientific studies of the foraging way of life, we can confirm Locke's account of the state of nature as mostly right. And we can see that the modern liberal ideas of equality, liberty, and dignity can be understood as appealing to that evolved human nature as shaped in the hunter-gatherer bands of our evolutionary ancestors.
And yet, one might object that, as Friedrich Hayek pointed out in his evolutionary account of liberalism, the liberalism of the Great Society--of the extended order of exchange in which millions of people can cooperate anonymously for their mutual benefit--requires a repression of the natural instincts shaped by life in ancient families and small bands. In those families and foraging bands, our ancestors lived in primitive communism, just as Karl Marx and Friedrich Engels recognized, in which wealth was distributed equally for the common good according to some deliberate plan. By contrast to this, a modern free market society requires that goods and services be distributed through market prices, which does not conform to any standard of social justice. The socialist rejection of the market system of allocation in favor of a deliberately planned distribution for the common good appeals to our evolved instincts for the socialism of families and small bands.
In fact, McCloskey observes, our families "are little socialist economies," and the "instinctive basis" for wanting a centrally planned society is that central planning really does work in a family household, and perhaps also in small bands and small business firms (BE, 577, 624). Moreover, McCloskey notes, the family can rightly be seen as the original social insurance scheme to provide care for children, the sick, the unemployed, and the old (BE, 605). The problem, however, is that while it is natural for a family or a band to be centrally planned according to the communist principle of "from each according to his ability, to each according to his need," it is not natural for large societies of millions of individuals to be centrally planned; and in such large societies, we need life to be organized by trade.
According to Hayek, this means that in large liberal societies, we must live in two worlds at once that are based on conflicting principles of order. We must neither apply the rules of the market to family life, nor apply the rules of family life to the market. Hayek explained: "If we were to apply the unmodified, uncurbed, rules of the micro-cosmos (i.e., of the small band or troop, or of, say, our families) to the macro-cosmos (our wider civilization), as our instincts and sentimental yearnings often make us wish to do, we would destroy it. Yet if we were always to apply the rules of the extended order to our more intimate groupings, we would crush them. So we must learn to live in two sorts of world at once" (The Fatal Conceit, 18).
But as Gaus and I and a few others have argued, Hayek is mistaken in his belief that our hunter-gatherer ancestors lived in a completely socialist or collectivist order with no individual autonomy, and therefore our evolved human nature must be suppressed if we are to live in a free society of autonomous individuals who trade with one another for mutual benefit. In fact, as McCloskey indicates, there is plenty of evidence for long-distance trading networks among our ancient foraging ancestors (BE, 22, 106-107, 283, 376, 403, 543-59). Even Hayek himself sometimes concedes that there is evidence for ancient trading (Fatal Conceit, 11, 16-17, 29, 38-45, 60, 133).
Moreover, there is also evidence, as Boehm and others have shown, that foragers assert their individual autonomy and liberty in resisting the attempts of anyone to establish dominance over others. If this is so, then the liberal ideas of equal liberty and dignity for all individuals and resistance to the sort of dominance hierarchies established in agrarian states can be understood as appealing to the original liberalism of the state of nature.
REFERENCES
Arnhart, Larry. 2015. "The Evolution of Darwinian Liberalism." Journal of Bioeconomics 17:3-15.
Boehm, Christopher. 1999. Hierarchy in the Forest: The Evolution of Egalitarian Behavior Cambridge: Harvard University Press.
Boehm, Christopher. 2012. Moral Origins: The Evolution of Virtue, Altruism, and Shame. New York: Basic Books.
Gaus, Gerald. 2015. "The Egalitarian Species." Social Philosophy and Policy 31: 1-27.
Jablonka, Eva, and Marion Lamb. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Cambridge: MIT Press.
Maryanski, Alexandra, and Jonathan Turner. 1992. The Social Cage: Human Nature and the Evolution of Society. Stanford, CA: Stanford University Press.
Richerson, Peter J., and Robert Boyd. 2008. "The Evolution of Free Enterprise Values." In Paul J. Zak, ed., Moral Markets: The Critical Role of Values in the Economy, 107-41. Princeton, NJ: Princeton University Press.
Rubin, Paul H. 2002. Darwinian Politics: The Evolutionary Origins of Freedom. New Brunswick, NJ: Rutgers University Press.
Turner, Jonathan H., and Alexandra Maryanski. 2008. On the Origin of Societies by Natural Selection. Boulder, CO: Paradigm Publishers.
Elaboration of some of my points here can be found in other posts here, here, here, here, here, here, here., here, here, here, here., here., here., here, and here.
We all recognize the importance of the Industrial Revolution, but few of us recognize that economic historians have uncovered other industrial revolutions at other times and places in history. Those other industrial revolutions did not bring a Great Enrichment--the explosive growth in wealth sustaining an explosive growth in population over the past two centuries, beginning in northwestern Europe and then spreading around the world. One of the deepest questions for all of the intellectual disciplines--the natural sciences, the social sciences, and the humanities--is how to explain why this has happened. Or, in other words, why is our world in the Bourgeois Era so very different from the world of all of our ancestors?
Bourgeois Equality (2016) is the third big book in a trilogy of big books that Deirdre McCloskey has written to answer this question. The previous two are The Bourgeois Virtues (2006) and Bourgeois Dignity (2010). All three books elaborate arguments that were first set forth in 1994 in an article--"Bourgeois Virtue"--in the American Scholar, written by Donald McCloskey before he became Deirdre. Every main idea, and sometimes even the exact wording, in the books comes from the article.
The plan for this intellectual project came to McCloskey while she was on an airplane and reading John Casey's book Pagan Virtue (1990). As suggested by Friedrich Nietzsche, Casey contrasts the pagan aristocratic virtues of Achilles, for whom courage is the primary virtue, and the plebeian Christian virtues of Saint Paul, for whom charity is the primary virtue. Today, McCloskey thought, most of us are bourgeois, and we are neither pagan aristocrats nor Christian plebeians. We are neither heroes nor saints. What are our bourgeois virtues? Or must we admit, as Gustav Flaubert and other bohemian critics of the bourgeois have declared, that the only way for the bourgeois to become good is to stop being bourgeois? Bourgeois liberalism has allowed more human beings to enjoy individual liberty, equal dignity, and economic prosperity than ever before in the history of the world. Prior to 1800, most people everywhere lived in grinding poverty. Now, few people live in such poverty. Surely, there must be something good in that, something virtuous.
The greatness of the Great Enrichment is evident in the economic data. McCloskey summarizes some of the data from economic historians (like Angus Maddison) and from the World Bank, the International Monetary Fund, and the Penn Tables (put together by scholars at the University of Pennsylvania) (Bourgeois Equality, 5-13). Expressed in present-day U.S. prices, corrected for exchange rates and inflation, the average human being prior to 1800 lived on $3 a day, which is the average today for Haitians and Afghans. Today, the world average, which includes the poorest people like the Haitians and Afghans, is $33 a day, which is about the level of present-day Brazil or of the United States in 1941. So average per person income has increased over the past two centuries by a favor of 10. And since the world population has increased over that same period from under one billion to over seven billion, we can say that the production and consumption of goods and services has increased worldwide by a factor of 70 (7 X 10). In the wealthier countries today, the average real income per person per day is well over $100, which means an income growth from 1800 to the present of 2,900%.
Prior to 1800, periods of increasing economic growth could double or triple average daily income--from $3 a day to $6 or $9 a day--but inevitably these periods of growth were followed by a decline back to subsistence levels. So, prior to 1800, real income per person could increase by 100% or 200% in times of great economic growth, but never by 2,900%, as has happened in the past two centuries.
McCloskey contends that the greatest transformation in human history was not the 450 years of sustained economic growth in England, 1348-1750, at a growth rate of one-tenth or two-tenths of 1 percent per year. And it was not the Industrial Revolution in Great Britain, 1760-1860, with growth over a hundred years of a factor of 2. The great transformation was the Great Enrichment, with growth of 5.87% per year and a factor of 100 over two centuries (BE, 532). There had been major growth phases in earlier history elsewhere in the world--early Song China and early Tokugawa Japan, for example--but these were periods in which growth rose by factors of 2 or 3, not factors of 10 or 30 or 100 (BE, 534-35).
Moreover, other measures of improving human conditions of life show the same Great Enrichment. Average life expectancies have doubled since 1800, for example, and literacy has increased from less than 10% in 1850 to almost 90% today. The increase in literacy indicates not just material enrichment, but also intellectual and spiritual enrichment.
Social scientists have offered many different kinds of explanations for this unprecedented turn in human history, beginning first in northwestern Europe and North America, and then spreading around the world. One explanation popular with many economists (such as Douglass North, Daron Acemoglu, and James Robinson) emphasizes the importance of economic, legal, and political institutions that favor economic growth--particularly, property rights, the rule of law, free trade, and general incorporation laws for forming economic corporations, which provided the incentives for economic exchange and innovation.
But while such institutional rules are necessary conditions for economic growth, McCloskey argues, they are hardly sufficient to explain the historically unique explosion in economic development that began after 1800. Good institutions are necessary, but only quick changes in good ideas can explain the quick move to the Great Enrichment. Ideas matter, McCloskey insists, particularly ethical ideas about the bourgeois life. What changed in the eighteenth century in Great Britain (preceded by the same change in the seventeenth century in the Dutch Republic) was that for the first time in human history the bourgeois life of trade-tested betterment--buying low and selling high--was judged not as morally corrupting, as it had been throughout history, but as morally virtuous and thus honorable.
For hundreds of thousands of years, human beings have expressed the bourgeois "propensity to truck, barter, and exchange," which has fostered economic growth. But it was not until the seventeenth and eighteenth centuries in northwestern Europe that philosophers like Adam Smith defended this as a virtuous activity that should be admired as protected by a system of natural liberty that would recognize the equal liberty and dignity of ordinary people in living their lives as they please. This change in the ethical rhetoric of ideas brought the Great Enrichment of the nineteenth century. This change was the move to liberalism, to Smith's liberal idea for "allowing every man to pursue his own interest his own way, upon the liberal plan of equality, liberty, and justice" (Wealth of Nations, Liberty Fund, 664, 687).
The institutions of property rights, the rule of law, and free trade can be found in many civilizations throughout human history. For example, as McCloskey points out, Genghis Khan's Pax Mongolia of the thirteenth century enforced property rights and the rule of law over a land empire stretching from Korea to Hungary, which protected global free trade throughout Central Asia. China had private property, extensive markets, and large firms many centuries before England had such institutions. Even ancient Mesopotamia had property rights and trade protected by law four thousand years ago. What all of these countries lacked, however, was the bourgeois ethics of Smithian liberalism that led to the Great Enrichment beginning in nineteenth century Great Britain.
Institutions without ideas are not enough to explain this. In fact, as McCloskey points out (BE, 518), even institutionalists like North will occasionally admit this. In Violence and Social Orders (2009) by North, John Wallis, and Barry Weingast, there is one passage (pp. 192-93) where the authors must fall back on ideational explanation for the transition to "open access societies": they speak of a "transformation in thinking," a "new understanding," "the language of rights," and "the logic of the argument." But then they fail to reflect on how this points to the primacy of liberal ideas advanced by people like John Locke and Adam Smith.
If McCloskey is right about the rhetorical appeal of liberal ideas promoting bourgeois ethics, as I think she is, then we must wonder what it is about evolved human nature that makes such ideas rhetorically appealing. Generally, McCloskey scorns evolutionary science in explaining social and economic history, because she fears that this falls into a crude social Darwinism, scientific racism, and eugenic materialism, which she sees, for example, in Gregory Clark's explanation of the British Industrial Revolution as arising from "survival of the richest" (Bourgeois Dignity, 266-95).
McCloskey also says, however, that her argument can be put into "evolutionary terms," because "I am arguing that the meme 'trade-tested-betterments are good' had reproductive success, and further, that on the success of the idea depended the material success of the modern world" (BE, 521-22). This would be a case of cultural evolution, of the sort studied by evolutionary scientists like Robert Boyd, Peter Richerson, and Joseph Henrich. Eva Jablonka and Marion Lamb have shown that in evolutionary history there are four systems of inheritance: genetic, epigenetic, behavioral, and symbolic. Of these four, the first three are manifest among nonhuman animals. Symbolic evolution is the one uniquely human line of evolutionary inheritance, which includes the whole realm of conceptual ideas and rhetorical persuasion. What McCloskey identifies as the Bourgeois Revaluation in liberalism belongs to human symbolic evolution.
McCloskey (BE, 631-39) also embraces an evolutionary theory of liberalism set forth in a paper by Gerald Gaus (2015), who relies largely on ideas developed by Christopher Boehm (1999, 2012) and by Richerson and Boyd (2008). This is the same evolutionary account of liberalism that has been defended by Jonathan Turner, Alexandra Maryanski, Paul Rubin, and me (in various writings as well as on this blog).
The basic idea, as McCloskey says, is that bourgeois liberalism is "reinstating a pre-agricultural equality" by establishing an equal dignity and liberty for ordinary people--including an "equality of genuine comfort"--that restores the equal autonomy of individuals enjoyed in hunter-gatherer bands for hundreds of thousands of years until the establishment of rigid class hierarchies in agrarian societies.
As I have argued in some earlier posts, this is a restatement of John Locke's argument for liberalism as the restoration of the natural liberty and equality that hunter-gatherers had in the "state of nature." Locke's account of the state of nature depended on the reports of Europeans about the foraging life of native Americans. "In the beginning," Locke declared, "all the world was America." Now, after two centuries of scientific studies of the foraging way of life, we can confirm Locke's account of the state of nature as mostly right. And we can see that the modern liberal ideas of equality, liberty, and dignity can be understood as appealing to that evolved human nature as shaped in the hunter-gatherer bands of our evolutionary ancestors.
And yet, one might object that, as Friedrich Hayek pointed out in his evolutionary account of liberalism, the liberalism of the Great Society--of the extended order of exchange in which millions of people can cooperate anonymously for their mutual benefit--requires a repression of the natural instincts shaped by life in ancient families and small bands. In those families and foraging bands, our ancestors lived in primitive communism, just as Karl Marx and Friedrich Engels recognized, in which wealth was distributed equally for the common good according to some deliberate plan. By contrast to this, a modern free market society requires that goods and services be distributed through market prices, which does not conform to any standard of social justice. The socialist rejection of the market system of allocation in favor of a deliberately planned distribution for the common good appeals to our evolved instincts for the socialism of families and small bands.
In fact, McCloskey observes, our families "are little socialist economies," and the "instinctive basis" for wanting a centrally planned society is that central planning really does work in a family household, and perhaps also in small bands and small business firms (BE, 577, 624). Moreover, McCloskey notes, the family can rightly be seen as the original social insurance scheme to provide care for children, the sick, the unemployed, and the old (BE, 605). The problem, however, is that while it is natural for a family or a band to be centrally planned according to the communist principle of "from each according to his ability, to each according to his need," it is not natural for large societies of millions of individuals to be centrally planned; and in such large societies, we need life to be organized by trade.
According to Hayek, this means that in large liberal societies, we must live in two worlds at once that are based on conflicting principles of order. We must neither apply the rules of the market to family life, nor apply the rules of family life to the market. Hayek explained: "If we were to apply the unmodified, uncurbed, rules of the micro-cosmos (i.e., of the small band or troop, or of, say, our families) to the macro-cosmos (our wider civilization), as our instincts and sentimental yearnings often make us wish to do, we would destroy it. Yet if we were always to apply the rules of the extended order to our more intimate groupings, we would crush them. So we must learn to live in two sorts of world at once" (The Fatal Conceit, 18).
But as Gaus and I and a few others have argued, Hayek is mistaken in his belief that our hunter-gatherer ancestors lived in a completely socialist or collectivist order with no individual autonomy, and therefore our evolved human nature must be suppressed if we are to live in a free society of autonomous individuals who trade with one another for mutual benefit. In fact, as McCloskey indicates, there is plenty of evidence for long-distance trading networks among our ancient foraging ancestors (BE, 22, 106-107, 283, 376, 403, 543-59). Even Hayek himself sometimes concedes that there is evidence for ancient trading (Fatal Conceit, 11, 16-17, 29, 38-45, 60, 133).
Moreover, there is also evidence, as Boehm and others have shown, that foragers assert their individual autonomy and liberty in resisting the attempts of anyone to establish dominance over others. If this is so, then the liberal ideas of equal liberty and dignity for all individuals and resistance to the sort of dominance hierarchies established in agrarian states can be understood as appealing to the original liberalism of the state of nature.
REFERENCES
Arnhart, Larry. 2015. "The Evolution of Darwinian Liberalism." Journal of Bioeconomics 17:3-15.
Boehm, Christopher. 1999. Hierarchy in the Forest: The Evolution of Egalitarian Behavior Cambridge: Harvard University Press.
Boehm, Christopher. 2012. Moral Origins: The Evolution of Virtue, Altruism, and Shame. New York: Basic Books.
Gaus, Gerald. 2015. "The Egalitarian Species." Social Philosophy and Policy 31: 1-27.
Jablonka, Eva, and Marion Lamb. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Cambridge: MIT Press.
Maryanski, Alexandra, and Jonathan Turner. 1992. The Social Cage: Human Nature and the Evolution of Society. Stanford, CA: Stanford University Press.
Richerson, Peter J., and Robert Boyd. 2008. "The Evolution of Free Enterprise Values." In Paul J. Zak, ed., Moral Markets: The Critical Role of Values in the Economy, 107-41. Princeton, NJ: Princeton University Press.
Rubin, Paul H. 2002. Darwinian Politics: The Evolutionary Origins of Freedom. New Brunswick, NJ: Rutgers University Press.
Turner, Jonathan H., and Alexandra Maryanski. 2008. On the Origin of Societies by Natural Selection. Boulder, CO: Paradigm Publishers.
Elaboration of some of my points here can be found in other posts here, here, here, here, here, here, here., here, here, here, here., here., here., here, and here.
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