Review of "Prehistory: the making of the human mind" by Colin Renfrew

I just wrote an amazon.com review for a book I finished. Thought I'd post it here too, in slightly revised fashion.

I do recommend this book, but certainly not as highly as I had hoped to. This is partly because it did not meet my expectations. I had very high hopes indeed of uploading a lifetimes worth of synthetic insight into human prehistory from one of the most famous names in the field. That hope was largely disappointed by this book. Perhaps I should have seen it coming, the book is only 240 pages long, certainly not space enough for a detailed treatise on prehistory (for that I have turned to Steven Mithen’s 600 page “After the Ice: A global human history 20,000-5,000 B.C.). Instead, I should have paid more attention to Renfrew’s glinting subtitle “The making of the human mind.” In fact I did see this, and was intrigued, but unfortunately, in the end found Renfrew’s thesis on that subject to be based on a dichotomy that I don’t believe exists.

This book is composed of two parts. The first part is Renfrew’s history of Prehistory, as a field of academic endeavor. This is in itself interesting tale. From a history of science perspective, there is always much to be learned from examination of successive emancipations from past biases and technological boundaries, and how those two factors feedback on each other. However, there is an odd disconnect from that story, it seemed to me, with the second part of the book. Renfrew periodically hypes up the paradigmatic technologies of radioisotopes first, and DNA methods most recently. The big anticlimax to me was that in the second half of the book, the curtain was finally drawn, and the DNA evidence was brought to bear in support of the “out-of-Africa” scenario and damning the longstanding alternative, the “multi-regional hypothesis.” However, Renfrew then dusts his hands, and is finished with DNA, saying that, in so many words, human evolution of any consequence for interpretation of prehistory, ended 60,000 years ago. Thanks DNA for helping us archaeologists put to rest a decades old dispute, and that’s all we need from you, we’ll take it from here again. From this point, Renfrew sets up his two-phase scenario for human prehistory: the "Speciation" phase (which DNA evidence has been and will be informative about), followed by the geologically allusive "Tectonic" phase which has lead to the arts, social, and economic hierarchies. He then erects "The Sapient Paradox" which follows the form of asking how could drastic cultural changes arise in the absence of any evolution in “the” human genotype?

Unfortunately for Renfrew’s entire logical setup, that consequential human evolution ceased 60,000 years ago is certainly not indisputable. He does very little in the way of a convincing argument, and in fact it becomes quite clear that his long and distinguished career in archaeology has not included becoming well versed in human population or evolutionary genetics. His claims that all humanity has one “genotype” is rather naïve. That we are all VERY closely related as members of the species Homo Sapiens is indeed a fact. Depending on exact study and metric, the estimates are 99.1%-99.5% similarity among modern humans. However, chimpanzees are 94-98% similar to us. Even bananas seem to share about half our genes. The question becomes, not how similar is the raw data, but among those small differences, what constitutes consequential difference? For those humans afflicted with cystic fibrosis, and certain other diseases, 99.999999% similarity is still the difference between life and death. One base-pair differences are not always so consequential, more often they are not. Many differences simply influence things like a propensity to grow on average 1cm taller, or to be slightly more susceptible to addictive behavior, or to taste bitterness differently, or to digest lactose past weaning. We are learning that human genetic variation includes millions of sites in the human genome that sum up to only a tiny fraction of the overall genome, yet in concert with each other and the environment, can trigger or suppress expression, and thus have large explanatory value for understanding human phenotypic variation. Such variation is certainly fodder for evolution. Why would natural selection (and sexual and artificial selection for that matter)cease acting on such extant variation? Some readers may not recognize this as such a bold claim, but it is. And of course, extraordinary claims require extraordinary evidence. Unfortunately, the most recent book to come out attempting to do just that, “The 10,000 Year Explosion” is a rather shoddy piece of science writing. In fact, ironically, that book is shamelessly poorly presented and almost infuriatingly flippant at times, while “Prehistory” is rather well executed and erudite, yet nonetheless fatally flawed in its biased assumptions about DNA.

In the end, I do think that much of the remainder of Renfrew’s book shows great synthetic understanding from the mind of a great scholar, and much worthwhile insight surely exists. I certainly don’t hold that Renfrew’s invocation of such concepts as “Institutional Facts” and the idea of increasing material engagement in prehistory do not offer some explanatory power toward understanding human prehistory. I would suffer from the same error Renfrew makes in dismissing a whole category of potentially useful analytical approaches to say so. However, I have to admit that I don't have a great deal of enthusiasm for “cognitive archaeology” and the book in general. If the entire premise is based on a false dichotomy, I’m not sure I have the wherewithal to parse out the truly explanatory bits from those that are intricate heuristic explanations that will soon be more elegantly explicable in light of the very methods he first touts when they fit his pre-conceptions and then arbitrarily dismisses when they don't: those methods using the inherent record of prehistory inside us: DNA.