Researchers have found a gene that could explain why we developed language and speech while our closest living relatives, the chimps, did not.
The gene called FOXP2 is a transcription factor, meaning it regulates other genes. Past research has suggested this gene remained relatively unchanged along mammal evolution until after humans and chimps diverged. And about 200,000 years ago, when modern humans appeared on the scene, scientists think two amino acids (building blocks of proteins) changed in FOXP2.
But whether that amino-acid modification had any real effect on us wasn't known. To find out, a team of researchers expressed the chimp and human forms of this speech gene in neuronal cells that essentially didn't express the gene, or make proteins that carry out that gene's instructions.
They found 116 genes that were expressed differently in humans compared with chimps, suggesting FOXP2 is responsible for those differences, the researchers say.
"We showed that the human and chimp versions of FOXP2 not only look different but function differently too," said study researcher Daniel Geschwind of UCLA. "Our findings may shed light on why human brains are born with the circuitry for speech and language and chimp brains are not."
Some of the genes are related to motor function, particularly cranial facial movements in humans.
Another group of genes differently expressed have been shown to be important for the development of the brain and connections between neurons. "We believe FOXP2 is not only important for the higher order cognitive aspect of language but also for the motor aspect of speech and language," lead researcher Genevieve Konopka, a postdoctoral fellow in neurology at UCLA, told LiveScience.
In addition to genes, past research has found the hyoid bone may have given us, and possibly Neanderthals, talking talents.
The study, which will be detailed in the Nov. 12 issue of the journal Nature, was funded by the National Institute of Mental Health, the A.P. Giannini Foundation and the National Alliance for Research on Schizophrenia and Depression.
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