Modern humans, Neanderthals shared common speech gene
Washington, Oct 19 : A new study by researchers at the Max Planck Institute for Evolutionary Anthropology has revealed that Neanderthals and modern humans shared a common gene involved in speech and language.
Lead researcher Johannes Krause said Neanderthals shared some of the prerequisites for language.
The gene, called FOXP2, is the only one known to date to play a role in speech and language. People who carry an abnormal copy of the FOXP2 gene have speech and language problems.
“The current results show that the Neanderthals carried a FOXP2 protein that was identical to that of present-day humans in the only two positions that differ between human and chimpanzee. Leaving out the unlikely scenario of gene flow [between the two lineages], this establishes that these changes were present in the common ancestor of modern humans and Neanderthals,” Krause and his co-researchers wrote in their study.
“The date of the emergence of these genetic changes therefore must be older than that estimated with only extant human diversity data, thus demonstrating the utility of direct evidence from Neanderthal DNA sequences for understanding recent modern human evolution,” the study said.
“From the point of view of this gene, there is no reason to think that Neanderthals would not have had the ability for language,” said Krause, however, noting that many as-yet-unknown genes could possibly underlie the capacity for language.
“Once found, those would have to be examined in Neanderthals as well,” he said.
The researchers extracted DNA from Neanderthal fossils collected in a cave in northern Spain.
They exhumed the bones under sterile conditions and froze them before transporting them to the laboratory.
They then extracted DNA and sequenced the Neanderthal FOXP2 gene, revealing that it was identical to the version found in modern humans.
To ensure that the Neanderthal DNA samples hadn’t been contaminated with human DNA, they also sequenced parts of their Y chromosome, which was found to be distinct from that of men today.
Previous analyses has shown that a very recent rise in the human FOXP2 variant had occurred as a result of strong selection, less than 200,000 years ago.
Svante Pääbo, also of the Max Planck Institute said: “since we know that Neanderthal and modern human populations diverged more than 300,000 years ago, we would have guessed that these changes in FOXP2 would have happened after we separated from Neanderthals”.
He said the human version of FOXP2 differed from that of chimps in two places.
The researchers said that in addition to its potential implications for the acquisition of language, the study had also marked the first time a specific nuclear gene had been retrieved from Neanderthals – opening the door to other breakthroughs in scientists’ understanding of human and Neanderthal evolution.
The study appears in the October 18 online issue of the journal Current Biology. (ANI)