Humans and Neanderthals may have interbred, but had no hybrids

December 5th, 2007 - 12:52 pm ICT by admin  

Washington, Dec 5 (ANI): A new study has suggested that humans may have interbred with Neanderthals, but there were no hybrids that emerged as a result.
The study was a result of the discovery of a 29,000 year-old Romanian skull called Cioclovina Calvaria, which is one of the oldest fossils in Europe with modern human features.
This finding led some experts to suspect that the fossil was a cross between a Neanderthal and a modern human.
But when Katerina Harvati, a senior researcher in the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology, and her colleagues took detailed 3-D measurements of the Romanian skull, they found out that its features aren’t quite a perfect match with present day humans.
For the research, the team compared their measurements with a similar head shape analysis of Neanderthals, modern humans and fossils of other hominids found in Europe, Africa and countries bordering the eastern Mediterranean Sea.
The researchers also studied animal hybrids and developed an unprecedented list of proposed criteria for evaluating whether or not a fossil specimen is a hybrid.
The criteria included the following: greater or much smaller size than the parental species, on average; evidence for developmental instability; possible occurrence of rare attributes, such as having extra teeth or bone joints; and possessing an intermediate shape.
“Cioclovina did not meet any of these criteria, which is a strong refutation of the hypothesis that it represents a hybrid,” said Harvati.
“It differs from living people only in subtle ways, and always well within the range of modern human variation,” Harvati told Discovery News. “It has, for instance, slightly heavier eyebrows than the average person, and is generally somewhat more robust than average,” she added, explaining that modern humans have gradually evolved to become more slight and slender than Upper Paleolithic people were.
The scientists support the single origin model of human evolution. This holds that modern humans evolved between 200,000 and 100,000 years ago in a single location - mostly likely Africa - with subsequent migration displacing archaic hominid populations, including Neanderthals, around the world. (ANI)

Tags: , , , , , , , , , , , , , , , , , , ,

Posted in Health Science |