Scientists have revealed that Neanderthals carried more copies of mutations that would alter the amino acid makeup of proteins than modern humans possess, which suggests that their populations across Eurasia were likely small and isolated.
According to the researchers, Neanderthals seem to have been few in numbers either over a long time or for some periods, which indicates that they have been subdivided in populations that had little contact with each other.
However, lead study author Sergi Castellano, at the Max Planck Institute for Evolutionary Anthropology, said that the fact that Neanderthals carried more copies of potentially detrimental mutations did not necessarily contribute to their extinction and no claim should be made that this is related to their extinction.
The scientists also found that skeleton genes changed more than expected within the Neanderthal lineage, while genes involved with pigmentation and behavior changed more in the modern human lineage.
The study was published online in the journal Proceedings of the National Academy of Sciences.