Right off the bat in Last Ape Standing, Chip Walter gives off hints of what eventually grows to become his thesis: that neoteny is the mechanism that defines human evolution. He doesn’t make a big flashy “science journalism” headline out of it—which speaks well to him as a writer, and as an articulator of arguments, as he lets his statements speak for themselves—but it is always there, lurking in the background. It begins with the big toe, with the move to bipedalism, which everyone really agrees is what sets us apart, at least initially, from the other apes. Chimps, gorillas and that ilk have big toes, but they are opposable, thumb-like. It doesn’t start like that, though; no, indeed, it starts straight, and then develops that bend during gestation. What if, instead, it…didn’t? I have to hand it to Walter; it is a pithy and plausible theory.
That isn’t the end of the neonatal conversation, by a longshot. He lays out the bare bones a little later—just what this “neoteny” is, and a little of its history as a concept—and he returns to it again and again. He spells it out in the discussion of “sensitivity” in epigenetics, where he posits that it is humans’ extended childhood—a compromise between big brains and bipedal hips—that allows youth to skip most animals’ “hardwiring” during extended pregnancy and (drastically) shorter childhoods. “[G]enetically similar, but behaviorally unique,” is how Walter puts it, and he even ascribes morality, attraction and the existence of the so-called “problem of other minds” to neoteny. Creativity and problem solving? An off-shoot of playing, of just doing things to see what happens; the picture he paints of humans being defined by their long periods of childhood is compelling.
Ultimately, Last Ape Standing is about humans. Or I should say Humans, capital-H, because I think that the other hominins, like Neanderthal and Erectus probably deserve to be under the small-h human umbrella with Homo sapiens. The other also-rans of history are brought into the mix as a way of illuminating a facet of humanity, and as an opportunity to muse on whether not having whatever trait is under discussion is what doomed them to extinction.
Personally, while I understand the reasons for asking “why Neanderthal went extinct but Humans didn’t,” I don’t think there is a pithy answer that will frame the narrative or provide closure to the existential question of why one group lived and dominated the planet and the other died off. As I touched on in my How to Think Like a Neandertal review, every time someone comes up with a reason Neanderthals couldn’t talk, science disproves it. I think that Human bias has a lot more to say than the science, when it comes to that particular can of worms. You know that genetic bottlenecking that the “mitochondrial Eve” comes out of? Well, one bad flu could have spelled doom for good old Homo sapiens. No rhyme or reason, no satisfying “why” or discreet answer. Just nature, red in tooth and claw.
As a brief aside, let me just mention something that I’ve thought about a lot, and that Mister Walter has apparently noticed as well. He mentions Homo erectus and the ubiquity of the Acheulean hand axe, comparing them to Swiss Army knives and cell phones. I have to actually wonder about that latter comparison, because I have often posited half in jest that I think the reason that cellphones are the size cellphones are is because…well, because of the evolutionary pressures of the Acheulean hand axe technology! I mean, those hominins carried those things around for 1.6 million years; that is a long time. In Wranham’s Catching Fire he discusses how the technology of fire and cooking changed the course of human evolution; technology already has the ape in a feedback loop. I think the physical similarity of a hand axe and a cell phone isn’t accidental.
Focusing on other hominins as the paradigm for talking about humanity does miss an opportunity to discuss something dear to my heart as a reader of anthropology books, however: behavioral modernity. Chip Walter touches on it briefly in his chapter “Beauties in the Beast,” but I would really have liked to see more about it. For me, that is the line of demarcation, that is the Rubicon. Homo sapiens is just another smart ape for 150,000 years, like Homo erectus or Homo neandertalis, with a roughly equivalent technological toolkit, until 70-50,000 years ago, something changes, and there is just an incredible bloom of symbolic culture. “Blades, beads, burials, bone tools, and beauty” as the mnemonic goes. Walter discusses it, but here is where I want to see the “why” question asked. Why! Why behavioral modernity, what jumpstarted it? My impulse is to discount “mutation” theories, and I personally favor the idea some linguistic critical mass, but I’m open to the discussion.
Ultimately, the take-away from this excellent book is in his discussions of neoteny, which he lays out incredibly well, positioning each point in an evolutionary context that just rings true. Chip Walter is also the author of Thumbs, Toes and Tears, another sort of pan-discipline book on the nature of humanity. I’ve already picked it up, which I think is the ultimate vindication for Last Ape Standing—if you finish a book and go right out to get another by the author…well, that’s the real test, isn’t it?