But now that the once popular “single-origin model” of the evolution of Homo sapiens has been disproved, and the previously controversial “multiregional hypothesis” has been proven by DNA evidence, perhaps we need a rethink. According to the multiregional hypothesis all modern people, including modern Africans, are the descendents of breeding and hybridising between separate ancestral groups, all at various stages of evolutionary development.
Evolutionary lice research has helped palaeoanthropologists, including Stringer, to embrace the multi-regional hypothesis. “I’m sure there is plenty more to come from the lice research,” he told me. We know that it took 4m years, 5-9m years ago, for our ancestors to completely split from archaic chimps. During that time hybrids would have been born that mated both with our ancestors and ancestral chimps.
Mitochondrial DNA from 147 people, drawn from five geographic populations have been analysed by restriction mapping. All these mitochondrial DMAs stem from one woman who is postulated to have lived ab7out 200,000 years ago, probably in Africa. All the populations examined except the African population have multiple origins, implying that each area was colonised repeatedly
And so was published in the year 1987 the paper which established in the public’s mind the idea of mitochondrial Eve, which gave rise to a famous cover photo in Newsweek. This also led to the Children of Eve episode on the PBS documentary NOVA. Here is the summary:
NOVA examines a controversial theory that traces our ancestry to a small group of women living in Africa 300,000 years ago.
As Milford Wolpoff has complained it is probably accurate to characterize the documentary as not particularly “fair & balanced.” Mitochondrial Eve may have been controversial, and subsequently plagued by issues of molecular clock calibration as well as spurious interpretations of the cladograms, but the tide of history was on its side, and PBS was telling that story. And the story was not just the primary science, rather, one had to understand the controversy in light of the debates among paleontologists and between paleontologists and molecular biologists. A group of researchers, spearheaded by Chris Stringer argued for the recent origin of modern humans from Africa on the basis of fossils alone. They were challenged by an established school of multiregionalists who argued for deeper roots of modern human populations, which derived from local hominins which diversified after the the migration of H. erectus out of Africa. The argument of the multiregionalists was that selective sweeps across the full range of the human populations gave rise gradually to modern humanity as we know it, a compound of specific ancient local features and trans-population characters which unified us into a broader whole. Stringer and company presented a simpler model where anatomically modern human being arose ~200,000 years ago in Africa, and subsequently expanded to other parts of the world, by and large replacing the local hominin populations. In the multiregionalist telling Neandertals became human beings, while Out of Africa would imply that Neandertals were replaced by human beings.