Jonathan Leaf loves straw man arguments. In my review of his book The Primate Myth for Law & Liberty, I criticized him for making a straw man argument. Now he has written a reply to my criticism by . . . making a straw man argument.
In my review, I pointed out that evolutionary biologists and anthropologists generally agree that to explain the evolution of human nature--or of any animal nature--they need to consider both phylogenetic evolution and convergent evolution. Phylogenetic evolution explains why human beings are similar to other primates with whom they share common genetic descent. Convergent evolution explains why human beings are different from other primates and similar to non-primate animals that have evolved adaptations for environments of evolutionary adaptation similar to the human environments of evolutionary adaptation.
Convergent evolution explains why a dolphin looks like a fish: it has evolved to have the fish-like anatomy that allows it to swim smoothly through its aquatic habitat. But phylogenetic evolution explains why a dolphin is not a fish but a mammal: it has all the mammalian traits that it inherited from its mammalian ancestors that were originally adapted for a terrestrial habitat.
Similarly, we need to consider both phylogeny and convergence in explaining the evolution of the human mind. Leaf correctly argues that the convergent evolution of the earliest human ancestors, as adapted for collaborative hunting, set them apart from other primates, who show very little collaborative hunting. But we also need to understand the phylogenetic evolution of the human brain.
Leaf criticizes what he calls the Primate Myth--the idea that humans are most like primates and unlike all non-primate animals--because this denies the convergent evolution that makes humans more like herd and pack animals than primates. But this Primate Myth is a straw man because most evolutionary scientists recognize both the phylogenetic similarities of humans to other primates and the convergent similarities of humans to herd and pack animals.
So, for example, Frans de Waal could see how similar humans are to chimps and bonobos because they share a common phylogenetic ancestry. But he also could see how similar humans are to some non-primates because of convergent evolution. For instance, de Waal recognized that while chimps and bonobos were sexually promiscuous, with no enduring pair-bonding of sexual mates, convergent evolution had made humans more like the pair-bonding animals. He observed: "The intimate male-female relationship, which zoologists have dubbed a 'pair bond,' is bred into our bones. I believe this is what sets us apart from the apes more than anything else."
Therefore, in attacking the Primate Myth that phylogenetic evolution counts for everything, and convergent evolution counts for nothing, in explaining human nature, Leaf is attacking a straw man.
In his rebuttal, Leaf criticizes me for "asserting that leading primatologists have not said that their study of apes is a means by which we might infer aspects of human nature." "Actually," he says, "they have been saying this for decades." Then he quotes from the first page of Chimpanzee Politics de Waal's remark that "apes hold up a mirror to us."
So here we go again with another straw man. I have not asserted that leading primatologists have never said that the study of apes can illuminate some "aspects of human nature." What I have asserted is that leading primatologists like de Waal have said that we need to study both phylogenetic evolution and convergent evolution to see how humans can be similar to apes in some ways but similar to non-primate animals in other ways.
It's the same for explaining the evolved nature of other animals. Emergent evolution explains why dolphins look similar to fish. Phylogenetic evolution explains why they are actually mammals and not fish.
Would Leaf have to say that since dolphins are so similar to fish that must mean that they really are fish and not mammals? Should his next book be all about dolphins with the title The Mammal Myth?
Or are we constructing a straw man here?
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