LOS ANGELES, Nov. 17 (UPI) -- U.S. researchers say they may have discovered why humans, who are genetically related to chimps, developed language and speech abilities while chimps did not.
A UCLA-Emory University team of scientists says it suspects part of the answer lies in a gene called FOXP2 that, when mutated, can disrupt speech and language in humans. The researchers say they've found major differences between how the human and chimp versions of FOXP2 work, perhaps explaining why language is unique to humans.
The scientists said their findings provide insight into the evolution of the human brain and may point to possible drug targets for human disorders characterized by speech disruption, such as autism and schizophrenia.
"Earlier research suggests the amino-acid composition of human FOXP2 changed rapidly around the same time that language emerged in modern humans," said Dr. Daniel Geschwind of UCLA. "Ours is the first study to examine the effect of these amino-acid substitutions in FOXP2 in human cells.
"We showed that the human and chimp versions of FOXP2 not only look different, but function differently too," he added. "Our findings may shed light on why human brains are born with the circuitry for speech and language and chimp brains are not."
The study that included Emory University Associate Research Professor Todd Preuss was published in the Nov. 11 early online edition of the journal Nature.
