Chance rather than natural selection gave Homo sapiens (modern humans) their elegant skulls, according to a new study by a team of anthropologists from the University of California, Davis.
As part of their study, Timothy Weaver and colleagues compared 37 measurements of the skulls of various modern human populations with those of Neanderthals.
Comparison of the mean divergence between Homo sapiens and Neanderthals and the mean divergence among groups of modern humans, revealed that the genetic drift, in which physical features change randomly, without an environmental driving force, was responsible for the skull difference between the two.
According to Weaver, the development of culture weakened the influence of the environment upon both Neanderthals and modern humans, but ultimately the two species drifted apart genetically when they became isolated from each other.
The findings appear in the Journal of Human Evolution, reports New Scientist.