Early Modern European

CHARACTERISTIC DIFFERENCES are shown between a Neandertal, represented by a French specimen, La Ferrassie 1, and an early modern, Dolni Vestonice 16, from the Czech Republic. Each aspect can be found in both groups, varying in degree and frequency, but they tend to appear as suites of features.

tal browridge, lack any clear functional significance and seem to reflect the genetic drift typical of isolated populations.

For those scholars who subscribe to the replacement model of modern human origins, the distinctive Neandertal morphology resulted from following an evolutionary trajectory separate from that of moderns. But for years, another faction of researchers has challenged this interpretation, arguing that many of the features that characterize Neandertals are also seen in the early modern Europeans that followed them. "They clearly have a suite of features that are, overall, different, but it's a frequency difference, not an absolute difference," contends David W. Frayer, a paleoanthropologist at the University of Kansas. "Virtually everything you can find in Neandertals you can find elsewhere."

He points to one of the earliest-known modern Europeans, a fossil from a site in southwestern Germany called Vogelherd, which combines the skull shape of moderns with features that are typically Neandertal, such as the distinct space between the last molar and the ascending part of the lower jaw known as a retromolar gap, and the form of the mandibular foramen—a nerve canal in the lower jaw. Additional evidence, according to Frayer and Milford H. Wolpoff of the University of Michigan at Ann Arbor, comes from a group of early moderns discovered in Moravia (Czech Republic) at a site called Mladec. The Mladec people, they say, exhibit characteristics on their skulls that other scientists have described as uniquely Neandertal traits.

Although such evidence was once used to argue that Neandertals could have independently evolved into modern Europeans, this view has shifted somewhat. "It's quite clear that people entered Europe as well, so the people that are there later in time are a mix of Neandertals and those populations coming into Europe," says Wolpoff, who believes the two groups differed only as much as living Europeans and aboriginal Australians do. Evidence for mixing also appears in later Neandertal fossils, according to Fred H. Smith, a paleoanthropologist at Loyola University of Chicago. Neandertal remains from Vin-dija cave in northwestern Croatia reflect "the assimilation of some early modern features," he says, referring to their more modern-shaped browridges and the slight presence of a chin on their mandibles.

Those who view Neandertals as a separate species, however, maintain that the Vindija fossils are too fragmentary to be diagnostic and that any similarities that do exist can be attributed to convergent evolution. These researchers likewise dismiss the mixing argument for the early moderns from Mladec. "When I look at the morphology of these people, I see robustness, I don't see Neandertal," counters Christopher B. Stringer of the Natural History Museum in London.

Another reason to doubt these claims for interbreeding, some scientists say, is that they contradict the conclusions reached by Svante Páábo, now at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and his colleagues, who in July 1997 announced that they had retrieved and analyzed mitochondrial DNA (mtDNA) from a Neandertal fossil. The cover of the journal Cell, which contained their report, was unequivocal: "Neandertals Were Not Our Ancestors." From the short stretch of mtDNA they se-quenced, the researchers determined that the difference between the Neandertal mtDNA and living moderns' mtDNA was considerably greater than the differences found among living human populations. But though it seemed on the surface that the species question had been answered, undercurrents of doubt have persisted [see "Ancestral Quandary," by

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