11 September 2006
Homo Sapiens Brow-Beaten By Neanderthals
by Kate Melville
We modern-day humans think that we're pretty damn good looking compared to our brow-ridged, potato nosed Neanderthal relatives, but new research indicates that perhaps it is we who are the evolutionary sideshow freaks. Based on comparative fossil studies, the new research, appearing in the August edition of Current Anthropology, claims that it's humans and not Neanderthals that should be on a separate evolutionary sub-branch extending from a common ancestor.
According to Erik Trinkaus, professor of Anthropology at Washington University in St. Louis, modern-day humans are out on a limb when it comes to the evolutionary family tree. A Neanderthal and modern human expert, Trinkaus' set about identifying traits of both groups by comparing characteristics deemed to be genetic markers, as opposed to characteristics considered environmentally influenced or otherwise anomalous. "I wanted to see to what extent Neanderthals are derived, that is distinct, from the ancestral form. I also wanted to see the extent to which modern humans are derived relative to the ancestral form," said Trinkaus.
Surprisingly, Trinkaus discovered that it was humans rather than Neanderthals that had far more distinctive characteristics, which he claims makes modern humans an evolutionary oddity. "What I came up with is that Modern humans have about twice as many uniquely derived traits than do the Neanderthals," said Trinkaus. "In the broader sweep of human evolution," says Trinkaus, "the more unusual group is not Neanderthals, whom we tend to look at as strange, weird and unusual, but it's us - modern humans."
Trinkaus believes that researchers have had the wrong end of the stick for too long, perhaps because of an egocentric tendency to see modern humans as the standard by which we measure all others on the "family tree". "The more academic implication of this research is that we should not be trying to explain the Neanderthals, which is what most people have tried to do, including myself, in the past. We wonder why Neanderthals look unusual and we want to explain that. What I'm saying is that we've been asking the wrong questions."
It is the many unique anatomical characteristics that represent modern humans that should be prodded and probed, argues Trinkaus, not those of the Neanderthal. "If we want to better understand human evolution, we should be asking why modern humans are so unusual, not why the Neanderthals are divergent. Modern humans, for example, are the only people who lack brow ridges. We are the only ones who have seriously shortened faces. We are the only ones with very reduced internal nasal cavities. We also have a number of detailed features of the limb skeleton that are unique."
Trinkaus implies that our position in the evolutionary scheme of things is based on assumptions consequent of our assessment of Neanderthals alone. But when considered in the context of the entire evolutionary lineage, it is hard to see how modern humans are not the odd ones out. "Every paleontologist will define the traits a little differently," concedes Trinkaus. "If you really wanted to, you could make the case that Neanderthals look stranger than we do. But if you are reasonably honest about it, I think it would be extraordinarily difficult to make Neanderthals more derived than modern humans."
Source: Washington University, St. Louis