Wednesday, January 25, 2017

Back to the Galapagos!

                                                                 The Cormorant

Today, my wife and I leave for our second cruise on The Cormorant around the Galapagos Islands (January 28 to February 4).  As I did for the first cruise in 2013, I will write a series of posts on our tour after we return.  The posts on the first cruise begin here.  The Cormorant is a yacht that is about the same size as the Beagle on which Darwin sailed.

After our 8-day cruise in 2013, we spent a week in Puerto Baquerizo Moreno, on the island of San Cristobal, where I participated in a special meeting of the Mont Pelerin Society at the Galapagos campus of the Universidad San Francisco de Quito.  The theme of the meeting was "Evolution, the Human Sciences, and Liberty."  I was one of the speakers--speaking on "The Evolution of Darwinian Liberalism."  I wrote a series of posts on all of the lectures and discussions, which begins here. 

This was a wonderful way to think about Darwinian evolution--first following Darwin's steps through the Galapagos as the natural laboratory of evolution, and then thinking about the implications of evolutionary science for classical liberalism at the MPS conference.  On this second trip, I want to continue thinking about how evolutionary science might support liberal social thought.

I realized that one 8-day cruise was not enough time to see the full range of life in the Galapagos.  That first cruise took us to the central, western, and northern islands (Santa Cruz, Isabela, Fernandina, Marchena, and Genovesa) during the cool and dry season of the year.  This second cruise will take us to the central and southern islands (Santa Cruz, Santiago, Santa Fe, San Cristobal, Espanola, and Floreana) during the warm and wet season of the year.

The ecological circumstances of the Galapagos are fundamentally shaped by the geological and climactic conditions.  The geological features of the Galapagos arise fundamentally from the islands being products of volcanic eruptions.  The volcanoes on the western islands of Fernandina and Isabela remain active.  The Wolf volcano in northern Isabela erupted as recently as May 25, 2015.  The volcanoes on the eastern and southern islands are inactive.

Darwin noticed that the volcanoes seem to lie along parallel straight lines.  He inferred that there were rifts on the ocean floor from which lava had been blurted and formed the islands. He spoke of "fissures of eruption."  Today, geologists agree with this, but their story is a bit more complicated.  They see the western islands as sitting on a deep-seated "hotspot" of volcanic activity that periodically sends volcanoes bubbling to the surface of the Nazca plate, which is moving to the south-east. As the Nazca plate moves, it carries each island away from the hotspot like a conveyor belt.

                                             Wolf Volcano Erupting in May of 2015

                                              Plate Tectonics of the Galapagos Islands

The Creation and Movement of Volcanoes in the Galapagos

As the islands move away from the hotspot over millions of years, they eventually sink under the sea.  The newest islands--Fernandina and Isabela--are rugged and inhospitable to life.  The older islands have had time for soil and vegetation to grow on what originally was pure lava, and thus they are somewhat more hospitable to life.

The other fundamental ecological factor for the Galapagos is climactic fluctuations due to ocean currents.

Between June and November, the cold Humboldt Current flowing up from the south lowers the temperature in the islands and causes some moisture in the warmer air to condense into a drizzling mist.  Beginning in December, the warm Panama Current flowing down from the northeast becomes more powerful, which raises the temperature of the water, creates a hot season, and with evaporation from the warmer water, clouds form and rain falls.  During an El Nino year, the Panama Current is particularly warm, which creates heavy rains.

So while in my first tour, I saw the youngest and most volcanically active islands during the cool and dry season of the year; in this tour, I will see the older and volcanically inactive islands during the warm and wet season.  Even in the wet season, however, the rain is confined mostly to the higher elevations, and so those of us who are hiking mostly at lower levels can be comfortable.

For anyone who is thinking about touring the Galapagos, I can recommend The Cormorant and the other two yachts of Haugan Cruises.  It's a luxury cruise with 16 passengers and 11 crew members.  Each stateroom has a balcony.  The food is good. The experienced naturalist guides are intelligent and engaging.  And as I indicated in my previous series of posts on the first trip, the guides offer a well-informed commentary on the evolutionary science of the Galapagos.

Of course, to speak of the evolutionary science of the Galapagos points to the deepest questions raised by any visit to the Galapagos: Does the variety of wildlife in the Galapagos provide evidence for the evolution of species by natural selection and other Darwinian mechanisms?  Or does it rather show the work of a Divine Creator or Intelligent Designer?

How do we explain the origin of those many species of life that are endemic to the Galapagos--species found here and nowhere else in the world?  There are over 4,000 species that are native to the Galapagos.  And of these about 1,600 species (40%) are endemic.  How exactly were so many species produced in these islands?

Those Biblical believers who read the first chapters of Genesis as a textbook of science say that God specially created these 1,600 species for the Galapagos, just as He created all other species.  The proponents of Intelligent Design Theory don't follow this literal reading of Genesis, but they do argue that all species must have been originally designed by some intelligent mind.

Doesn't it seem a little strange that the Creator chose to specially create these 1,600 species for the Galapagos and no where else?

Both the Creationists and the Intelligent Design proponents argue that the failure of Darwinian biologists to explain exactly when, where, and how a process of evolution created these species shows that we must assume that this requires a Divine Creator or Intelligent Designer.

But notice the rhetoric of negative argumentation here.  The Creationists and Intelligent Design proponents challenge the Darwinians to explain the step-by-step pathway by which the species endemic to Galapagos evolved by purely natural causes.  If the Darwinians cannot do this, then it's assumed that this failure proves the truth of Creationism or Intelligent Design. 

The sophistical fallacy in such argumentation becomes clear as soon as one notices that the Creationists and Intelligent Design proponents do not explain exactly when, where, and how the Creator or Intelligent Designer created the species for the Galapagos.  So they don't satisfy the standards of proof that they apply to the Darwinians.

So, for  example, the Creationists and Intelligent Design proponents have conceded that Peter and Rosemary Grant have observed evolutionary change in Darwin's finches in the Galapagos, particularly in the size and shape of their beaks.  But they argue that this is only microevolution--evolutionary change within a species--and not macroevolution--the evolutionary emergence of new species from ancestral species.  And yet, these proponents of Creationism and Intelligent Design have not provided any explanation of exactly when, where, and how God or the Intelligent Designer created the finches and other species endemic to the Galapagos.

The Grants have spent over 40 years of their life carefully studying the finches in the Galapagos as they empirically test hypotheses about evolution.  Have any creationist scientists made the same effort to test their hypotheses about how the Creator did His work in the Galapagos?

There is  another possibility--theistic evolution.  In the beginning, God might have created the laws of nature, but then allowed the natural laws of evolution to create all the species of life, including those endemic to the Galapagos. 

Darwin suggests this in the last paragraph of The Origin of Species:
"It is interesting to contemplate a tangled 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 upon 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 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 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."
The Galapagos  Islands are perhaps the best place in the world to feel the grandeur in this view of life.

Saturday, January 21, 2017

Is Monogamy for the Birds?


If monogamy is the pairing of a single male and a single female to cooperate in the generation and rearing of offspring, this looks like monogamy.  A male and a female penguin have given birth to a chick that they are now rearing.

If this is so, then it might seem that Thomas Aquinas was right in arguing that birds show that monogamy is natural, and thus part of natural law, for those animals who require the cooperative parental care of both mother and father to secure the generation, feeding, and education of their offspring.  Thus, natural law dictates monogamous marriage for human beings insofar as they are like these birds in needing biparental care for children.  I have written previously about Aquinas's biological argument for the natural law of monogamy (here and here).

Across most groups of animals, monogamy is rare.  But over 90% of birds are monogamous, in that pairs of males and females form partnerships in the breeding season to generate and rear offspring.  The male can contribute in many ways--by helping to build and maintain the nest, by helping to incubate the eggs, by feeding the chicks and the mother, by guarding the nest, and by protecting the offspring from predators.  The importance of male parental care has been demonstrated experimentally: if male parental care is reduced or eliminated, reproductive success (measured as the number of fledged young per brood) is reduced (Alcock 2013, 224-25).  This seems to confirm Aquinas's argument.

The emperor penguins show the intense devotion that bird parents can have for their offspring.  They nest on the ice in Antarctica in the middle of the winter, caring for one egg, and then chick, in total darkness with temperatures down to minus 80 degrees Fahrenheit and wind of up to 100 miles an hour.  Here is how biologist Bernd Heinrich describes it:
"The eggs are laid in May and June after the birds have walked far enough onto the ice so that the spring ice breakup will not reach the young until they are old enough to handle life in the water.  After the female has laid her egg, it is carefully transferred onto the male's feet and tucked up into his brood pouch.  he is then stuck with the egg (or vice versa) as she returns to the sea.  During his continuous care of the egg during her over two-month absence, he loses about 40 percent of h is body weight.  It is pitch black most of the time, except possibly for the southern lights shimmering in the skies.  He sleeps a great deal, but during the howling blizzards at the deep subzero temperatures the whole colony of thousands of males of which he is a part contracts and presses against each other to conserve heat.  Other penguins are highly territorial, but the emperors cannot be, or they would not survive the cold.  Without each other for protection against the lements, they would too quickly use up their fat reserves and then starve; they need to huddle during their long fast in the cold to conserve calories.  By July, when the eggs start to hatch, the males may feed the chicks with milklike secretions produced by glands in the esophagus.  But then the females start to return from the sea to bring predigested food that they can regurgitate.  In the crowds of hundreds, they all call for their mates, and somehow the mated pairs recognize each other, are attracted only to each other, and unite, transferring their young chick from the male's feet onto the female's and providing it with food that she has brought.  He, by now emaciated, then heads to the sea to feed himself and also collect food for his chick.  His return journey is made shorter by the receding ice edge, melting in the spring warmth." (Heinrich 2010, 83-84)
This story is now well-known from the hit documentary film of 2005--March of the Penguins, narrated by Morgan Freeman, who spoke of this as "a heartwarming story about family and the power of love."  Like Aquinas, some religious conservatives pointed to this film as showing that these birds could teach human beings about the virtues of monogamous love and parental care.

But some people protested that to speak of these birds as showing "love" was crudely anthropomorphizing these animals.  Similarly, some people have complained about Aquinas's "biologizing" of natural law as failing to see that nonhuman animals cannot provide any moral standards for human beings, because human morality has nothing to do with animal biology.

Heinrich was asked by the New York Times to write an article about this controversy as to whether it was proper for Freeman to speak of these penguins as showing "love."  Heinrich wrote:
"The unspoken rule is that this four-letter word is to be applied only to one creature on earth, Homo sapiens.  But why?  A look at the larger picture shows this presumption of exclusivity is utterly unproved.  In a broad physiological sense, we are practically identical not only with other mammals but also with birds--muscle for muscle, eye for eye, nerve for nerve, lung for lung, brain for brain, hormone for hormone--except for difference of detail of particular design specifications.  Functionally, I suspect love is an often temporary chemical imbalance of the brain induced by sensory stimuli that causes us to maintain focus on something that carries an adaptive agenda. Love is an adaptive feeling or emotion--like hate, jealousy, hunger, thirst--necessary where rationality alone would not suffice to carry the day.  Could rationality alone induce a penguin to trek 70 miles over the ice in order to mate and then balance an egg on his toes while fasting for four months in total darkness and enduring temperatures of minus 80 degrees Fahrenheit and gusts of wind of up to 100 miles an hour?  And bear in mind that this 5-year-old penguin has just returned to the place of its birth from the open sea, and thus has never seen an egg in his life, and could not possibly have any idea what it is or why it must be kept warm.  Any rational penguin would eventually say, 'To heck with this thing, I'm going back for a swim and eat my fill of fish.'" (Heinrich 2010, 80-81)
Although Heinrich was expecting criticism from his fellow biologists, those who wrote to him praised him for recognizing the evolutionary biology of emotions.  The criticism came from everyone else, who said that it was degrading to human dignity to speak of love as a chemically induced state of mind serving the same reproductive function as it does for other animals.

While Aquinas insisted on the uniqueness of human beings as the only animals capable of conceptual thought and speech and of morality in the strict sense, he would have agreed with Henrich that nonhuman animals do have emotions, that these emotions are what motivate animal movement, and that they do have "a certain likeness of moral good [similitudo boni moralis] in them, in regard to the soul's passions" (ST, I-II, q. 24, a. 4, ad 3).  We can know that they have such emotions, because "the internal passions of animals can be gathered from their outward movements: from which it is clear that hope is in dumb animals" (I-II, q. 40, a. 3).

It is not clear, however, that the modern evolutionary understanding of mating among penguins and other birds fully supports Aquinas's claim that birds show a monogamous bonding of male and female in the generation and care of offspring that manifests the natural law of monogamy for human beings.

For Aquinas, natural monogamy requires a pair-bonding of male and female over their entire life that excludes any sexual mating with anyone else outside the pair.  What scientists now know about birds suggests that they depart from this standard in three ways.  First, the monogamous pair-bonding of birds almost never lasts longer than one or two breeding seasons.  Second, even while the pair-bond lasts, there is often copulation with others outside the pair.  Third, the pair-bonding is sometimes between birds of the same sex.

While many people found the March of the Penguins to be an endearing display of "family values," some people pointed out that the bonding between the mated pair of penguin parents and the bonding of the parents with their offspring almost never last beyond one breeding season.  Emperor penguins can live up to 50 years.  And once a mated pair has reared one chick, the male and the female must forage independently for several years; and when they return to the colony for another breeding season, they find different mates.  So once the kid is out of the nest, the parents are free to divorce and find new mates. 

This is true for most birds, although a few, such as ravens, seem to pair for life.  Ravens form a lifelong attachment to their mates.  This has various benefits for them.  Raven young require a longer period of rearing than is the case for other birds.  If a raven pair holds a territory throughout the year, they don't have to look for a new nesting site every spring.  A raven pair also hunts and forages together, so that their strong and enduring bond makes them a coordinated team.

But even with raven couples, it is unclear as to whether they might occasionally engage in sexual mating with birds outside the pair.  In the 1980s, new techniques in molecular genetics allowed scientists for the first time to determine the genetic parentage of birds, and they were surprised to discover that many of the offspring being reared by pair-living individuals were genetically related to the female but not the male, and thus they were products of what came to be called extra-pair copulations (EPCs) (Reichard 2003; Alcock 2013, 224-41).  Ornithologists had always assumed that monogamous male birds were advancing their reproductive success by helping their female partners in caring for their genetic offspring.  But now it seemed that some monogamous males were being cuckolded, because they were caring for the offspring of another male.

So it seems that social monogamy is not necessarily the same as genetic monogamy or sexual monogamy.  Pair-living birds who cooperate in caring for offspring are in a monogamous social partnership.  But if some of the offspring are genetically related to the female but not the male, then we could say that the mating system here is not genetic monogamy, but either genetic polyandry (a female mating with multiple males) or genetic polygyny (a male mating with multiple females), although the system for caring for offspring is socially monogamous. 

This creates two puzzling questions for the Darwinian scientist.  What do males gain from being socially monogamous but genetically polygynous, when this means that some males will be cuckolded?  And what do females gain from being socially monogamous but genetically polyandrous, when this means that they have to trick their social partner into caring for another male's offspring?  Evolutionary biologists have offered various hypotheses as to how the benefits of these mating strategies outweigh the costs, with costs and benefits measured in terms of reproductive fitness.  But there is no general agreement on which hypothesis is correct.

This is a similar puzzle in explaining human monogamy.  Through much of human history and in some societies today, polygyny (men with multiple wives) has been permitted or even preferred.  This makes sense from an evolutionary perspective, because, as Robert Trivers (1972) argued, polygynous mating manifests the difference in mating effort and parental investment between males and females.  The most reproductively successful men have many more children than the most fertile women, because while a man can potentially impregnate thousands of women, a woman can give birth to no more than about 20 to 25 children at the outer limit.  So it seems that a man's reproductive fitness is promoted by investing his time and energy in mating with as many women as possible and investing very little in the parental care of his many offspring, while a woman's reproductive fitness is promoted by investing a little in mating and investing a lot in the parental care of her few offspring. 

If the successful rearing of human offspring typically requires parental care from both parents, then we might expect that women would want to mate with men who seem likely to be caregiving fathers.  A polygynous father will have to divide his paternal caregiving among his many offspring, and we can expect that the wives will have to compete with one another for the father's parental investment in their children.  But if the father controls great social resources (high status and great wealth), he can possibly provide those resources to his wives for the successful rearing of the children.

Aquinas says that polygyny is partly natural and partly unnatural (ST, suppl., q. 65, a. 1).  It is natural insofar as it is possible for one man with great resources to mate with multiple wives and provide for the successful generation, feeding, and education of their children.  But it is unnatural insofar as the jealousy of the multiple wives will drive them to fight amongst themselves in competing for the husband's attention and resources, and thus the conjugal bonding of husband and wife will not achieve the sort of marital friendship that is possible in a monogamous marriage.  In fact, the wives in polygynous marriages are often treated as almost the slaves of the husband.  The conflict among the co-wives can be softened somewhat by sororal polygyny--one man marrying sisters--because then each woman will be related to the children of the other women as t heir nieces or nephews.

By contrast, polyandry (one wife with multiple husbands), Aquinas says, is totally contrary to nature, because the wife can be impregnated by only one man at a time, and the men will be reluctant to invest parental care in children if they are uncertain as to whether the children are theirs (ST, suppl., q. 65, a. 1, ad 8).  The sexual jealousy of men is stronger than that of women, so that it is much harder for men to share a wife than it is for women to share a husband.  And yet the conflict among the co-husbands can  be softened somewhat by fraternal polyandry--one woman marrying brothers--because then each man will be related to the children of the other men as their nieces or nephews. 

Aquinas thought human polyandry was impossible, but actually there have been a few rare cases of polyandry, particularly in Tibet, Nepal, and adjacent areas.  And often these have been cases of brothers marrying one woman.  This seems to have been an adaptation to a harsh mountainous environment where farming is difficult, and arable land is scarce, and so brothers marry a single wife so that their land is held together rather than divided between the brothers, and this also maximizes the number of males for working the land (Durham 1991; Levine 1988; Sanderson 2014, 175-80).  The brothers often fight over this arrangement.  Clearly, they are making the best of a bad situation.  In showing the instability of polyandrous marriages, they confirm Aquinas's observation that polyandry is unnatural (Levine and Silk 1997).

So should we agree with Aquinas that we are left with monogamous marriage as the most natural form of marriage?  By the time Aquinas was born in the 13th century, the Catholic Church had abolished polygyny and made monogamy the only legal form of marriage across Europe.  Aquinas saw this as the fulfillment of natural law, because monogamous marriage best satisfies the two natural ends of marriage--the parental care of children and the marital friendship of men and women.

Notably, however, Aquinas admitted that there were exceptions to this norm of monogamy.  A wealthy woman might provide for the successful rearing of her children without need for the father's help (SCG, III, chap. 122, sec. 7).  And a wealthy man might generate a child through fornication and then help the unmarried mother in the rearing of their child (ST, II-II, q. 154, a. 2) .  But Aquinas claimed that marriage law must conform to what is generally best and not what works only in exceptional cases.

Even if we agree with Aquinas about monogamous marriage as naturally normative, however, we might wonder whether his ignorance of how to trace genetic lineage blinded him to the distinction between social monogamy and genetic monogamy, or between marriage systems and mating systems.  Beginning in medieval Europe, monogamous marriage has spread around the world as the legal norm; and thus it seems that as Aquinas argued, human beings have followed the example of the monogamous birds.  But now that we see that even most of those monogamous birds are engaging in extra-pair copulations, we have to doubt that social monogamy coincides with genetic monogamy.  And isn't this often as true for human beings as for birds--that human beings who are socially monogamous are often genetically or sexually polygamous?  Or, in other words, monogamous marriage systems are not necessarily monogamous mating systems?  (See Low 2003.)  Doesn't this suggest that human beings are by nature a mildly polygamous species, and consequently that genetic monogamy is almost never fully attained across a society, although socially-imposed monogamous marriage systems are common?

If this is true, then perhaps Aquinas was unrealistic in upholding life-long heterosexual monogamy with extensive biparental care and absolutely no extra-pair copulation as the natural standard.  He might have been right that by nature this satisfies the fullest range of natural human desires--including sexual mating, parental care, conjugal bonding, familial bonding, and friendship.  But predictably many human beings will fail to achieve this.  It might, therefore, be prudent for marriage law to tolerate these human imperfections--by, for example, legalizing no-fault divorce and remarriage and by not punishing adultery and fornication as crimes.

This seems to follow from Aquinas's prudent observation that it does not rightly belong to human law to punish all vices:
"Human law is established for the collectivity of human beings, most of whom have imperfect virtue.  And so human law does not prohibit every kind of vice, from which the virtuous abstain.  Rather, human law prohibits only the more serious kinds of vice, from which most people can abstain, and especially those vices that inflict harm on others, without the prohibition of which human society could not be preserved.  For example, human laws prohibit murders, thefts, and the like" (ST, I-II, q. 96, a. 2).
Therefore, Aquinas argues, human law "permits some things because it is unable to direct them, not because it approves them" (ST,  I-II, q. 93, a. 3, ad 3; q. 96, a. 2).  If human law permits without approving what we know by nature to be vices, we can rely on social pressure in civil society to disapprove of those vices, but without the coercive punishment of law.  This is what some scholars have identified as the "permissive natural law" that supports the modern idea of natural rights (Tierney 1997, 2014).

Moreover, as I have argued (here), there is some empirical evidence that Aquinas was correct in claiming that by nature monogamous marriage supporting sexual partnership and parental care promotes human happiness

"Permissive natural law" might also permit without approving homosexuality.  Aquinas condemns homosexuality as clearly "contrary to nature" for two reasons.  First, nonhuman animals do not engage in homosexual conduct.  Second, homosexuality does not lead to procreation and parental care of children (Summa Theologica, I-II, q. 30, a. 3; q. 31, a. 7; q. 94, a. 3, ad 2, q. 94, a. 6; II-II, q. 154, aa. 11-12).. We now know, however, that Thomas was mistaken about both of these points (as I have argued in a previous post here).

Scientists have observed homosexual behavior in 471 animal species--167 species of mammals, 132 species of birds, 32 species of reptiles and amphibians, 15 species of fishes, and 125 species of insects and other invertebrates.  Scientists have also observed that same-sex pairs have successfully reared young in at least 20 species.  In some cases, one or both partners are the biological parent(s) of the young they raise together.  In other cases, the partners adopt and care for young without being the biological parents.  Moreover, in some cases, the same-sex couples seem to be more successful in their parenting than opposite-sex parents.

We also now know that homosexuality is biologically natural in that it arises through the interaction of many biological factors in the early development of fetuses and children--genes and sex hormones shape the body and the brain in early life so that people are naturally predisposed to become heterosexual, bisexual, or homosexual (LeVay 2011; Sanderson 2014, 144-52). 

Penguins are one of the birds that show homosexuality.  Penguins can mate with a same-sex partner, incubate a fertile egg, and then raise their chick for three months.  If Aquinas is right about birds providing us with models of the natural law of monogamy and parental care, does this show that homosexual monogamy and parental care is natural?  If so, does this suggest a Thomistic natural law argument for the Supreme Court's decision in Obergefell v. Hodges (2015) upholding the constitutionality of same-sex marriage (as I have argued here, and here,).


Alcock, John. 2013. Animal Behavior, 10th ed. Sunderland, MA: Sinauer Associates.

Durham, William H. 1991. Coevolution: Genes, Culture, and Human Diversity. Stanford, CA: Stanford University Press.

Heinrich, Bernd. 2010. The Nesting Season: Cuckoos, Cuckolds, and the Invention of Monogamy. Cambridge, MA: Harvard University Press.

LeVay, Simon. 2011. Gay, Straight, and the Reason Why: The Science of Sexual Orientation. New York: Oxford University Press.

Levine, Nancy. 1988. The Dynamics of Polyandry: Kinship, Domesticity, and Population on the Tibetan Border.  Chicago: University of Chicago Press.

Levine, Nancy, and Joan Silk. 1997. "Why Polyandry Fails: Sources of Instability in Polyandrous Marriages." Current Anthropology 38: 375-98.

Low, Bobbi S. 2003. "Ecological and Social Complexities in Human Monogamy." In Ulrich H. Reichard and Christophe Boesch, eds., Monogamy: Mating Strategies and Partnerships in Birds, Humans, and Other Mammals, 161-76. Cambridge: Cambridge University Press.

Reichard, Ulrich H. 2003. "Monogamy: Past and Present." In Reichard and Boesch, Monogamy, 3-25.

Sanderson, Stephen K. 2014. Human Nature and the Evolution of Society. Boulder, CO: Westview Press.

Tierney, Brian. 1997. The Idea of Natural Rights. Grand Rapids, MI: Eerdmans.

Tierney, Brian. 2014. Liberty & Law: The Idea of Permissive Natural Law, 1100-1800. Washington, DC: Catholic University of America Press.

Trivers, Robert. 1972. "Parental Investment and Sexual Selection." In Bernard Campbell, ed., Sexual Selection and the Descent of Man, 1871-1971. Chicago: Aldine.

Saturday, January 14, 2017

Does Ethnic Nationalism Have Greater Genetic Fitness than Classical Liberalism?

Both Friedrich Hayek and Paul Rubin have argued that the liberal social order has emerged through a process of evolution as more adaptive than any other social order.  Both Hayek and Rubin have been challenged by some critics who argue that classical liberalism is actually maladaptive in reducing genetic fitness, and that ethnic nationalism is more adaptive in maximizing genetic fitness.  This argument has become part of the new wave of ethnic nationalism that has recently been rising in various parts of the world.

Hayek’s argument is that through a process of selective cultural group evolution, the market order has shown its evolutionary superiority to the alternatives by producing the explosive growth in population and wealth of the past 200 years.  Some of his critics do not dispute the growth in wealth coming from the market order of expanding global trade and specialization.  But they do dispute the claim that market liberalism shows its adaptive superiority in producing growth in population.

The demographic transition—the drop in fertility rates among wealthy people in liberal societies that began to appear at the end of the 19th century—is said by Hayek's critics to show that market liberalism is maladaptive because it reduces reproductive fitness relative to those illiberal groups with higher fertility rates.

Hayek recognized that the demographic transition could slow the growth in population among wealthy people in liberal societies (The Fatal Conceit, 125, 128).  But he did not see this as weakening his argument for the adaptive superiority of market orders in producing population growth.  After all, population can still grow even if the rate of growth has slowed.  And even if the fertility rate of wealthy people in liberal societies declines, the population of those societies could still grow because those societies will attract immigrants (Law, Legislation, and Liberty, vol. 3, p. 159).

The response of the critics has been to argue that there are two reasons why the mass immigration of outside groups into liberal societies is evolutionarily harmful to those liberal societies:

One is that, as ethologist Frank Salter (2004, 2007) explained, in his critique of Rubin, the mass migration from groups into other groups reduces the relative fitness of the receiving population.  Second, differential birth rates potentially biased in favour of newcomers can itself constitute a form of group selection against the original group. Ultimately, if reproductive fitness is the measure of success in the evolutionary process, there is no equally suitable replacement for sheer reproduction.

According to ethnic nationalists like Salter, market liberalism is maladaptive for two reasons.  People in liberal societies tend to have low fertility rates, and liberal societies tend to have open borders that allow the immigration of outside groups with high fertility rates.  If this continues into the future, eventually the native ethnic groups in liberal societies will become small minority groups, or they will go completely extinct. 

So, for example, Salter warns that liberal globalism is not adaptive for Americans, because if unrestrained immigration of non-European people continues, America’s majority white population will eventually become a minority, and America will change from being a nation state to being an ethnically plural state.  This shows that liberal globalism is maladaptive, because liberal ethnic groups have lower reproductive fitness than illiberal ethnic groups. 

The alternative, Salter argues, is “universal nationalism”: every ethnic group should have a right to its own national homeland in which it practices ethnic nepotism—discriminating in favor of its own ethnic identity, so that each ethnic group would pass on its genes to the next generation of people living in its homeland.  The success of ethnic nationalism would depend on two policies: promoting high fertility in the native ethnic group and restricting the immigration of outside ethnic groups. 

Salter has elaborated his reasoning in his book On Genetic Interests (2003), which has become one of the most influential books among ethnic nationalists today, particularly the “alt-right” white supremacists in the United States.  In his review of Salter’s book, American white supremacist Jared Taylor claimed that Salter provides “a scientific justification for racial consciousness and activism.” 

Rubin has responded to Salter.  Like Hayek, Rubin makes an evolutionary argument for classical liberalism.  He claims that modern liberal societies satisfy the preferences or desires of their citizens better than any other social order that has appeared in human history, and that evolutionary science can show that those desires belong to the evolved human nature that evolved to maximize fitness in the environments of evolutionary adaptation that prevailed among our Paleolithic foraging ancestors.  Thus, Rubin starts with the standard assumption of economists that human beings desire to maximize utility.  But his novelty is in arguing that human utility functions have evolved by natural selection, and therefore evolutionary science can explain and clarify the formation of those utility functions.

But while our natural human desires originally evolved to maximize reproductive fitness in the environments of evolutionary adaptation, Rubin argues, there is no reason to believe that those desires will always maximize fitness in the circumstances of modern life.  So, for example, we can assume that the desires for sexual mating and parental care originally evolved as part of the human nature of our evolutionary ancestors because those desires tended to maximize fitness in ancient environments.  But in modern environments, those desires might not maximize fitness. 

Like all animals, human beings must decide how many offspring to produce and how much to invest in each offspring, and that decision requires trade-offs that depend upon the socioecological circumstances in which they live.  Throughout most of human history, most human beings lived in a world of poverty and high infant mortality, in which it was adaptive for parents to produce many offspring, while investing few resources in each, so that the quantity of offspring was favored over quality.  But in a modern world of wealth and low infant mortality, and a world where high levels of education and training are important for social success, parents might want to produce few children in which they can invest a lot in the education and training of those children; and those parents might also want to delay reproduction in order to have more time to invest in their careers. 

By the beginning of the twentieth century, almost all adults in the liberal societies had learned to read, which had never happened in human history.  Now, increasing numbers of people are going to college and professional schools for the education necessary to be successful in societies where social and economic success requires high levels of training and cognitive talent.  This makes children very costly for parents who want to invest heavily in the education of their children, and as the cost of children rises, the demand for children declines. This can produce small families with low fertility rates that can fall below the levels necessary for replacement. 

People desire to increase the likelihood that they and their children will be socially and economically successful, even when this results in low fertility rates that do not maximize reproductive fitness.  In other words, people desire sexual mating, parental care, wealth, social status, and other goods; but they don’t desire reproductive fitness.  A liberal social order is better than any other social order in allowing people to satisfy their natural desires, but in doing that, it does not necessarily maximize reproductive fitness.

Salter seems to agree with Rubin that modern liberal societies largely succeed in satisfying the natural desires of their citizens.  But Salter believes that these desires are mistaken, and that people are incorrect in not desiring reproductive fitness.  Salter concedes this point when he laments that ethnic nepotism is not instinctive, and therefore serving ethnic genetic interests requires artificial cultural strategies devised by modern scientific reasoning, and that no ethnic state has ever succeeded in securing an adaptive ethnic group strategy.  Salter admits that in protecting their genetic interests in modern states, “humans can no longer rely on their instincts” (On Genetic Interests, 28).

Salter identifies various “ethnic states” in the modern world, but he admits that “no state yet developed has reliably kept its promise as an adaptive ethnic group strategy” (221), which includes “the best known modern ethnic state”—Nazi Germany (231).  None of the ethnic states he mentions have succeeded in raising the total fertility rate of its ethny.  The drop in the total fertility rate for native Germans continued under the Nazis, and the Germans have had one of the lowest fertility rates for any population in the world.  Other modern ethnic states that Salter mentions—such as Malaysia—show the same failure to raise fertility rates.  Malaysia provides special protection for the Malay majority at the expense of the Chinese and Indian minorities, and yet the total fertility rate for Malays has fallen below replacement levels.

It’s not clear what policies ethnic nationalists would have to promote to raise fertility rates.  Should they impose severe tax penalties on those couples who do not produce lots of children?  Is this the kind of illiberal policy that ethnic nationalism would require to maximize the genetic fitness of the ethny?

The success of the multiethnic liberal culture is manifest in the passage by white American legislators of the U.S. Immigration and Nationality Act of 1965, which eliminated the national origin and racial restrictions on immigration, including restrictions on immigration from Africa and Asia.  The American ethnic nationalists would have to overturn this act.

When ethnic nationalists warn that a liberal culture must inevitably lead any ethnic group that adopts that culture to below replacement levels of fertility that will bring the extinction of that group, they assume that steep declines in fertility rates are never reversed.  In fact, that is not true.  Some of the lowest fertility rates appeared in Europe and the United States in the 1930s, but this was followed by the post-World War Two rise in fertility rates (the “baby boom”).  Beginning in the late 1960s, the rates began another steep decline.  But in recent years, there has been some evidence that as societies move into the very highest levels of human development—as measured by long life expectancy, great wealth, and high levels of education—the declining trend in fertility is reverse.  Recently, Sweden and some other highly developed societies have shown this, although the increase in fertility is still not up to replacement levels (see Mikko Myrskyla et al., “Advances in Development Reverse Fertility Declines,” Nature 460 [6 August 2009]: 741-43.)

For me, this shows that the natural human desire for children and parental care will always assert itself, although parents in the socioeconomic circumstances of modern liberal societies will often prefer to invest heavily in fewer children, which can reduce reproductive fitness.
Paul H. Rubin, Darwinian Politics: The Evolutionary Origin of Freedom (New Brunswick, NJ: Rutgers University Press, 2002).
Paul H. Rubin, "Utility, Fitness, and Immigration: Reply to Salter," Journal of Bioeconomics 9 (2007): 53-67.

J. Philippe Rushton, "Ethnic Nationalism, Evolutionary Psychology, and Genetic Similarity Theory," Nations and Nationalism 11 (2005): 489-507.

Frank K. Salter, "Estimating Ethnic Genetic Interests: Is It Adaptive to Resist Replacement Migration," Population and Environment 24 (2002): 111-40.

Frank K. Salter, On Genetic Interests: Family, Ethny, and Humanity in an Age of Mass Migration (New York: Peter Lang, 2003).
Frank K. Salter, "Is Ethnic Globalism Adaptive for Americans?" Population and Environment 25 (2004): 501-527.
Frank K. Salter, "Proximate and Ultimate Utilities: A Rejoinder to Rubin," Journal of Bioeconomics 9 (2007): 69-74.
Other pertinent posts are here, here, here, here, here, here, and here.

Sunday, January 08, 2017

Biological Historicity and the Gombe Chimpanzee War

Yesterday was the 43rd anniversary of the beginning of the Gombe Chimpanzee War, which began on January 7, 1974, and ended on June 5, 1978. 

Since 1960, Jane Goodall had been studying the chimpanzees along the eastern shore of Lake Tanganyika in Tanzania (in what was first called the Gombe Stream Reserve and then later Gombe National Park).  She became a mythic celebrity through the articles and television documentaries about her work produced by the National Geographic Society.  Initially, she seemed to have discovered a chimp Garden of Eden free of violent conflict.  Even her name--Jane Goodall!--seemed to fit the myth.

But then, at the beginning of 1973, she and her colleagues noticed that the chimps had formed two separate communities--the northern or Kasakela community, based on the valleys of the Kakombe and Kasakela rivers, and the southern or Kahama community, based on the valley of the Kahama river.  By early 1974, they saw the first of a series of attacks by the Kasakela community on the Kahama community, which led over four years to the complete annihilation of the Kahama community.

Here is how Goodall described the first attack:
"In January 1974 a large mixed party of Kasakela individuals traveled southward. At 14115 hours six adult males  (Hugo, Humphrey, Faben, Figan, Jomeo, and Sherry), an adolescent male (Goblin), and a female in estrus (Gigi) began to travel more purposefully southward. The others stayed behind. From time to time calls were heard from the south, and the chimpanzees began to travel quickly and silently in that direction. Suddenly they came upon Godi, who was feeding in a tree.  He leaped down and fled. Humphrey, Jomeo, and Figan were close on his heels running three abreast; the others followed. Humphrey grabbed Godi's leg, pulled him to the ground, then sat on his head and held his legs with both hands, pinning him to the ground.  Humphrey remained in this position while the other males attacked, so that Godi had no chance to escape or defend himself."
"Figan, Jomeo, Sherry, and Evered beat on Godi's shoulder blades and back with their hands and fists; Hugo bit him several times. Gigi raced around and around, screaming loudly. Goblin kept out of the way."
"Finally Humphrey released his victim, and the others stopped their attack, which had lasted ten minutes. Hugo, screaming loudly, stood upright and hurled a large rock at Godi; it fell short.  The attacking party left and moved rapidly to the south, uttering pant-hoots and displaying.  Throughout the attack, all had been screaming loudly.  Later, calls were heard farther south.  The Kasakela party hurried toward them, then stopped, eventually returning to their core area."
"After the attack, Godi remained motionless for a few moments, then as his attackers moved off, he slowly got up and looked after them, screaming.  he was very badly wounded: a great gash extended from his lower lip down the left side of his chin, and his upper lip was swollen.  He was bleeding from his nose and from cuts in the side of his mouth.  There were puncture marks on his right leg and between his ribs on the right side, and he had a few small wounds on his left forearm.  Godi was never seen again, despite the fact that research staff continued to work in the Kahama area until 1978." (Goodall 1986, 506-507)
Notice that all of these chimps have proper names, which convey the individual uniqueness of each chimp's personality and life history.  For example, Gigi is the only female in the attacking Kasakela group.  In Goodall's  "Who's Who" of the Gombe chimps, she describes some of the distinctive traits of Gigi as a remarkably male-like female: "Gigi's behavior is very like that of a male. She is large and strong for a female, and often aggressive. Her display rate is high, and she sometimes performs waterfall and streambed displays, behavior very rarely seen in other females. She is assertive in her interactions with community members, even on occasion standing up to attacks by adult males, and since 1967 has unequivocally been the top-ranking female. She has been seen to hunt and capture prey more than any other female and is quite fearless in her determination to stand up to the defensive attacks of adult monkeys" (ibid., 66-67).

Goodall's description of the attack on Godi is part of her detailed military history of the four year war in which the Kasakela community extinguishes the Kahama community and takes over its territory.  The military expansion of the Kasakela community is stopped when they reach the boundary of the Kalande community, which is too strong to conquer.

Here we see what I call biological historicity: biology is a historical science of contingent events in the lives of individual organisms.  Those who insist on a dichotomy between biology and history, and who argue that only human beings have a history, so that human history cannot be part of biology, are mistaken.  In fact, all organisms are individually unique with unique life histories.  That becomes particularly clear in the study of animal behavior, which must be a study of individual animals living through the history of their communities. But to do this requires long-term studies of particular communities in which individual animals can be identified and followed through their life histories.  This must be done to achieve what I have called the biopolitical science of political animals, which moves through three levels of history--natural history, cultural history, and biographical history.

We can see this in Goodall's study of the Gombe chimps.  It takes many years of continuous observation to identify the individuals in the community and then to see how they develop over their entire lives.  Some chimps have been known to live into their 50s, although most chimps are lucky to live to their late 30s or early 40s.  So at least 30 to 40 years of observation are required to see complete life histories.  And it takes even longer to see the course of history over multiple generations.  For many reasons, it's hard for scientists to do this.  They must devote many decades of their lives to one study site, and they must secure funding to support their work over all these years, which is difficult to do.  If Goodall had left Gombe after 10 or 15 years of work, she would never have seen the Gombe Chimpanzee War; and she might have continued to report that chimps don't kill members of their own species.

It is remarkable that such long-term studies of animal communities with records of the life histories of recognizable individuals have been extremely rare, and they have grown only in recent decades (Clutton-Brock and Sheldon 2010a, 2010b).  The longest-running field studies are of passerine birds in the Netherlands beginning in the 1930s (Kluijver 1951).  Thousands of birds were banded so that they could be individually identified over their lives.  Since the 1960s, long-term field studies with records of individual life histories over 20 to 30  years have been conducted for different bird species and for mammals (including marmots, lions, savannah baboons, bighorn sheep, and red deer, as well as chimpanzees).

Only through such studies can one see how individual animals change as they age, how earlier stages in life history influence later stages, how the social structure of a community arises from the history of relationships between individuals, how each community develops its own unique cultural traditions, how individuals differ in their traits, how genes and environment interact over time, and how the evolutionary process of adaptation to variable circumstances and contingencies works.

In doing this, we see that human beings are not the only animals whose social lives are shaped not just by genetic evolution but also by cultural history and individual life history.  And once we see this, we see that a biosocial science cannot be a purely genetic science, because it must include the study of animal cultural history and animal personalities. (This shows why the political scientists promoting "genopolitics"--John Hibbing, James Fowler, and their colleagues--are wrong in assuming that biopolitics does not include biopolitical history.)

In response to Thomas Aquinas's claim that natural law is "that which nature has taught all animals," such as sexual mating and parental care, many critics have objected that this cannot be true, because animal behavior is rigidly determined by instincts, in contrast to the freedom of human conduct through cultural learning and individual judgment.  But one can recognize the mistake in this objection once one sees that the social life of non-human animals is culturally and individually variable, and thus any biological natural law of animal behavior, including human behavior, must be a historical science of uniquely individual life histories played out in the contingent history of unique communities with unique cultural traditions.


Clutton-Brock, Tim, and Ben C. Sheldon. 2010a. "The Seven Ages of Pan." Science 327:1207-1208.

Clutton-Brock, Time, and Ben C. Sheldon. 2010b. "Individuals and Populations: The Role of Long-Term, Individual-Based Studies of Animals in Ecology and Evolutionary Biology." Trends in Ecology and Evolution 25:562-573.

Goodall, Jane. 1986. The Chimpanzees of Gombe: Patterns of Behavior. Cambridge, MA: Harvard University Press.

Kluijver, H. N. 1951. "The Population Ecology of the Great Tit, Parus m. major L." Ardea 39:1-135.

Some of these points have been elaborated in a previous post that includes links to other pertinent posts.

Friday, January 06, 2017

Lecturing on Natural Law at Cambridge University, March 4

On March 4th, I will be at the University of Cambridge to participate in "A Symposium on the Philosophical and Theological Foundations of Law and Justice in Honour of Amanda Perreau-Saussine Ezcurra (1971-2012)." 

The symposium will be at the Lecture Theatre LG 18, Faculty of Law.

My paper for this symposium will be "The Darwinian Science of Thomistic Natural Law."

Other participants include Tobias Schaffner (University of Cambridge), John Cottingham (University of Reading), Nicholas Lombardo (Catholic University of America), James Bernard Murphy (Dartmouth College), Sean Coyle (University of Birmingham), Gerald Postema (University of North Carolina School of Law), James Crawford (Judge at the International Court of Justice), James Stoner (Louisiana State University), Nigel Simmonds (University of Cambridge), Nick McBride (University of Cambridge), and Guglielmo Verdirame (King's College London).

Wednesday, January 04, 2017

The Extinction of the Shakers Vindicates Darwinian Natural Law

The only Shaker community still existing is at Sabbathday Lake in New Gloucester, Maine.  The community's website has just announced the death of Sister Frances Carr on Monday, which leaves only two Shakers alive today--Brother Arnold Hadd and Sister June Carpenter.  So if there are no new recruits to the community, the Shakers will soon go completely extinct.  This vindicates Darwinian natural law, because it shows that communist communities that deny the evolved natural desires for mating, marriage, and private property must eventually fail and become extinct.

In Darwinian Natural Right, I appealed to the history of such utopian communist communities--particularly, religious communism in the Oneida Community and secular communism in the Kibbutz--as showing that communism is contrary to Darwinian natural right because it frustrates the natural desires of evolved human nature. (My posts on the kibbutz are here and here.)  I noted that these utopian communities showed the futility of Plato's "second wave" in The Republic--the proposal for abolishing private families and private property among the rulers in the perfectly just city.

The Shakers were founded by Ann Lee in 1747 in England.  In 1774, she fled to the New World with eight of her followers.  Ann Lee had married, but her marriage was unhappy because her fear of her own sexual impulses made the conjugal act disgusting to her, although she gave birth to four children.  She scolded her own mother for her "carnal acts of indulgence." She finally decided that celibacy was necessary for Christian salvation as an expression of virginal purity.

She supported this with a theology based on the Bible.  She saw the original sin of Adam and Eve as the sexual lust of their animal nature.  Jesus Christ came to save us from this animal depravity.  He taught that "in the Resurrection, they neither marry, nor are given in marriage, but are as the angels of God in Heaven" (Matt. 22:30).  The Apostle Paul taught that "He that is unmarried careth for the things that belong to the Lord, how he may please the Lord; but he that is married careth for the things of the world, how he may please his wife" (1 Cor. 7:32-33). 

Ann Lee taught that those who joined the Outer Order of Shakers could continue to have marriage and private property so that "all such as desire to live in nature propagating their own species, keep the law of nature" (A Holy, Sacred, and Divine Roll and Book, p. 30, quoted in Muncy 1974, p. 19).  But those admitted to the Inner Order would have to give up marriage, sexual intercourse, and private property, because they must "keep the law of Grace where the dominion of Christ is established in souls, and where the law of Grace reigns, and the law of nature is superseded" (ibid., 20).  They would become as the angels in Heaven.  So while she recognized that natural law governed most human beings most of the time, she thought the truly redeemed Christians of the Shaker Inner Order could show how "the law of nature is superseded."

The continuation of Shaker communities depended on adding new members in one of two ways.  Either new adults could be recruited to join. Or orphaned children could be adopted by the community, and at maturity the adopted children could decide whether to say or leave.  Sister Frances Carr was adopted when she was 10 years old, and then as an adult she decided to stay for her entire life.

There were once many Shaker communities scattered over the Eastern United States, and there was a total of as many as 6,000 members before the Civil War.  But since then the numbers have dwindled, and now it's down to one community with a total of two members.  The Shakers illustrate Friedrich Hayek's claim that in the evolution of religious traditions, "the only religions that have survived are those which support property and the family" (Fatal Conceit, 137).

But notice that this history of the Shakers does not prove that such socialist communities are completely impossible.  There will always be a few human beings--like Ann Lee and her followers--who can bear the sacrifice of celibate socialism.  They thus show what Thomas Aquinas identified as the variability in the natural temperament of individuals.  After all, Aquinas himself had the natural temperament that allowed him to join the celibate mendicant order of the Dominicans.  This natural variability in personality is manifest even in nonhuman animals, some of whom are celibate, and others of whom are homosexual (as indicated in posts here and here.)  But such a natural temperament will be rare among human beings, and even those with such a temperament are likely to suffer some emotional costs.

The Shakers and hundreds of other utopian communes were free in the United States to form as voluntary associations.  And thus a liberal social order is open to the formation of socialist communities for those who want to live in such communities, as long as membership is voluntary.  In this way, liberalism supports a largely open society in which all ways of life are possible, except those that use violent coercion to enforce membership.

This illustrates how a Darwinian liberalism of natural law allows for both cultural and individual variability within the constraints of evolved human nature.  Human nature constrains but does not determine human culture, and human nature and human culture jointly constrain but do not determine human individuals.

So, hey, those of you with the natural temperament for socialist celibacy can take off to Sabbathday Lake and save the Shakers from extinction!


Muncy, Raymond Lee. 1974. Sex and Marriage in Utopian Communities: Nineteenth-Century America. New York: Penguin Books.

Stein, Stephen J. 1994. The Shaker Experience in America: A History of the United Society of Believers. New Haven, CT: Yale University Press.