© Jens Schlueter/AFP/GettyThe human version of the gene FOXP2 harbours changes not found in chimpanzees or other primates.
The evolution of human language was once thought to have hinged on changes to a single gene that were so beneficial that they raced through ancient human populations. But an analysis now suggests that this gene,
FOXP2,
did not undergo changes in Homo sapiens' recent history after all - and that previous findings might simply have been false signals."The situation's a lot more complicated than the very clean story that has been making it into textbooks all this time," says Elizabeth Atkinson, a population geneticist at the Broad Institute of Harvard and MIT in Cambridge, Massachusetts, and a co-author of the paper, which was published on 2 August in
Cell1.
Originally discovered in a family who had a history of profound speech and language disorders, FOXP2 was the first gene found to be involved in language production
2. Later research touted its importance to the evolution of human language.
A key 2002 paper found that humans carry two mutations to FOXP2 not found in any other primates
3. When the researchers looked at genetic variation surrounding these mutations, they found the signature of a 'selective sweep' - in which a beneficial mutation quickly becomes common across a population. This change to FOXP2 seemed to have happened in the past 200,000 years, the team reported in Nature. The paper has been cited hundreds of times in the scientific literature.
Comment: The evidence suggests that a cataclysmic event 11,500 years ago caused the dramatic climate shifts which resulted in mass extinctions as well as a massive decline in species populations across the board: