“We're still genetically adapting to language,” says John Hawks, an anthropologist and specialist in human evolution at the University of Wisconsin at Madison, Wisconsin, in the USA.
Hawks has discovered that eight genes associated with hearing show signs of having evolved over the most recent 40,000 years. Some of the gene changes took hold only two-three thousand years ago.
Speech a recent phenomenon
According to Hawks, the changes in the hearing genes indicate that our ears are still adapting to human speech, which evolution experts believe first developed about 50,000 years ago. At that time, humans had existed for more than two million years, making speech a relatively recent development.
Speech is worthless without ears able to sense and discriminate sounds at the sound frequencies of speech. Our ears are still improving these abilities, according to Hawks.
Hawk's analyses of a data base with gene information from different continents indicate that many human genes besides the hearing genes have changed in recent human evolution.