Neanderthal Variations

As the sequencing technology for DNA gets more accurate and efficient scientists are learning more and more about the various twists and turns in the evolutionary history of hominids.

For example, tomorrow researchers at the Universite de la Mediterranee in France will announce findings which indicate that there were at least three different subgroups of Neanderthals.

Neanderthals are a hominid species that lived between about 130,000 and 30,000 years ago. Although humans share a common ancestor species with the Neanderthals, our relatives began diverging about 700,000 years ago, with the two groups becomong permanently distinct 300,000 years later (source).

Neanderthals coexisted with humans for a while, and may even have interbred with us - although the strong differences in phenotypical features (eg., how they look) suggest to me that this is highly unlikely. However, Neanderthals became extinct about 30,000 years ago, leaving Homo sapiens as the last surviving Hominid species on the planet. And scientists are still debating the causes for their extinction, but various data indicate the combination of competition with humans for resources and rapid climate change.

Using computer simulations to analyze DNA sequence fragments from 12 Neanderthal fossils, researchers found that the species can be separated into three, or maybe four, distinct genetic groups. The evidence points to a subgroup of Neanderthals in Western Europe, another in Southern Europe near the Mediterranean, a third in Eastern Europe and the Middle East, and possibly a fourth in Western Asia.

Although the authors of the paper outlining the findings admit that their categorization is based on limited data, since they only have fragments of mitochondrial DNA sequences from a small sample of individuals.

Silvana Condemi, one of several paleoanthropologists working on the project, reports:

"Because the Neanderthals lived in a very vast territory, and their evolution took place over a very long time, we wonder if there were sub-populations, or if it was a unique population... Other studies show differences between Neanderthals and modern humans. For the first time we are working just within Neanderthals and taking into account the diversity within that group... We give a confirmation that the Neanderthals are not one homogeneous group."

In future studies, the researchers have said they would like to compare their genetic data to what is known about physical distinctions among Neanderthals from different regions, as well as cultural differences, such as unique tool use among various populations.