Fossils matter. Fossils are evidence. That was Milford Wolpoff’s refrain in the 1987 NOVA documentary which heralded the long cresting of mitochondrial Eve and Out of Africa. Fossils remain highly relevant and important when it comes to deeper time phylogenetic relationships, but it does seem that they have only served to supplement the genetic data when it comes to recent human origins (e.g., calibrate and fine-tune molecular clocks). The paleoanthropologist Tim White, whose own position on human origins is at some contradiction from Milford Wolpoff’s, nevertheless felt the need to reiterate the relevance of fossils at a conference several years ago where most of the participants were geneticists (we received a preview of Ardi). Chris Stringer, who advocated for an Out of Africa model before Allan Wilson and his students roiled the academic waters often seems to have been relegated to nothing more than an adjunct to the molecular biologists in the public mind despite his priority. I think we are a turning point, and must acknowledge that recent human origins can no longer remain a one horse buggy. Genetics itself in the form of ancient DNA research, as well as more powerful analytic techniques utilizing larger autosomal data sets, have overturned and challenged the old conventional wisdom gleaned from trusting inferences derived from the patterns of variation of extant populations.
Consider two books from the early 2000s, The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry, and The Real Eve: Modern Man’s Journey Out of Africa. Both were ambitious works drawing bold lines between the patterns of history and genes, disproportionately maternally transmitted mtDNA (ergo, the references to Eve). Even at the time they were works of hubris, mtDNA is one locus, tracing one long uninterrupted line of foremothers. But it misses the total genome variance, and may be subject to various biases. A decade on though we now have grounds to suspect that much of the story told in both works is false. Europeans may have a more complicated history than we could have imagined. Some of the assumptions behind the second book, that most of today’s genetic variation crystallized during the Last Glacial Maximum ~20,000 years ago, also seems likely to be false.
The genetic data no longer cohere together in a plausible integrated whole. And that is of course the beauty of science, that it is subject to revision and revolution, that it eats away at its own foundations on occasion when those foundations are wanting. The very tools of modern genetics have undercut the confidence in genetics as a whole to answer broad expansive historical questions on its own. This is not a flaw in genetic science, it is the strength of science generally. Unlike some systems of thought science does not rest upon timeless creeds and formulas.
So where now? We need to do more than give lip service to a multidisciplinary perspective. We need to embrace it. This means a new relevance and importance to those who know and can interpret the fossil record. It also means more attention to anthropological and historical patterns, which may indicate the probable sample space of genetic outcomes. It will be harder and more uncertain work than what has come before, but the results will hopefully exhibit closer fidelity to the reality that was. False certainty is worse than an admission of ignorance
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