I have a review of Marlene Zuk's new book, Paleofantasy, in this week's Nature: "Evolutionary biology: Twisting the tale of human evolution" .
I can't replicate my review here, but for people who have access to Nature I thought I'd bring attention to it. And if you don't have access, I wanted to share a couple of my reactions.
It was a fun book for me to read. Zuk brings a light-hearted skepticism to a broad array of topics in human evolution. She took as her focus a collection of "paleo-advice" ideas: barefoot running, paleo diet, back-to-nature parenting advice. She then added some uncritically-accepted scientific notions about our evolution, such as the idea that agriculture was "the worst invention ever devised". To each of these topics, she brings an array of recent science questioning or disproving the assumptions. The result is not to debunk ideas, but to give a fuller (and more nuanced) perspective on how much we know (and don't know) about our evolution.
The serious issue underlying all these topics, which Zuk recognizes, is the difficulty of reconstructing Pleistocene environments. Some hypotheses assume a fairly detailed model of ancient environments -- the so-called "environment of evolutionary adaptedness". But ancient humans lived in an array of environments, more different than each other in many ways than different parts of today's globalized world. We are unquestionably living in environments no ancient humans knew, in population size, density, disease, lifespan, and many other ways. But in other ways, our difference from some ancient people is trivial compared to their diversity. Are we well-adapted to live in cities? Perhaps not in some ways, but maybe in others.
Probably the best part of my review to share is the end:
As an anthropologist, I observe that Zuk's use of the term 'fantasy' is just an emphatic way of describing the hypothesis-forming that is essential to evolutionary science. We play with hypotheses, explore their predictions and try very hard to falsify them. So it is, in a way, unremarkable that so many hypotheses proposed by anthropologists about ancient environments now seem to be wrong — and, in a few cases, even ridiculous.
It means that science is working. Genomics, high-resolution climate records, and microscopic and isotopic evidence have changed our understanding of what the past has to offer. With that in mind, let the next round of palaeofantasies begin.
Zuk's "very brief" overview of human evolution is a lot shorter than in other recent books on the topic. I found this to be a merciful change -- how many times do I really need to read about the Australopithecus-to-humans timeline? Readers who don't already know the basic timeline are unlikely to pick up the book, I would guess. Still, if you're looking for a "latest news" about early humans, this book is not directed that way. Where it excels is its coverage of recent evolutionary changes and the shifts in Holocene environments and genetics.
The book is not without its weak points. Without quite enough of the "paleo-advice" topics to carry the whole story, there were some real differences in tone across the chapters, with some a bit drier than others.
People coming to this book for "the right answer" about ancient environments are not going to find it. There is no right answer, at least not a scientific one, for many of the topics covered here. Zuk has done well to talk to a range of scientists, covering these different aspects of our evolutionary history, and discuss the reasons for their disagreement.
I wish scientists would do that for themselves more often!