How and when did we first become able to speak?

How and when did we first become able to speak? A new analysis of our DNA reveals key evolutionary changes that reshaped our faces and larynxes, and which may have set the stage for complex speech.

The alterations were not major mutations in our genes.

Instead, they were tweaks in the activity of existing genes that we shared with our immediate ancestors.These changes in gene activity seem to have given us flat faces, by retracting the protruding chins of our ape ancestors.

They also resculpted the larynx and moved it further down in the throat, allowing our ancestors to make sounds with greater subtleties.

However, other anthropologists say changes in the brain were at least equally important. It is also possible that earlier ancestors could speak, but in a more crude way, and that the facial changes simply took things up a notch.

The “Our results support the notion that evolution of the vocalization apparatus of modern humans is unique.”

However, other researchers say that the study, while important, does not tell the whole story of speech evolution.In particular, changes in the brain’s ability to process vocalizations made by others may have been just as important as the anatomical changes, if not more so, says Erik Trinkaus at Washington University in St Louis.

“Anatomy doesn’t impede primates from producing distinct vocalizations that are homologues to different human vowels,” says Adriano Lameira of the University of St Andrews in the UK.

He has previously shown that orangutans can mimic some of the sounds of human speech. What’s more, a 2016 study found evidence that monkeys’ vocal tracts could produce speech-like sounds if only their brains could control them precisely enough – although this finding is disputed.

Speech may have gradually improved over the course of hominin evolution. There is evidence that Neanderthals and Denisovans could speak, at least to some extent.

“Neanderthals most likely had brains capable of learning and executing the complex maneuvers involved in talking, but their speech would not have been as clear and comprehensible as ours, perhaps accounting in part for their extinction,” says Philip Lieberman of Brown University in Rhode Island. “I think Neanderthals could talk, but more indistinctly than us.”

Journal reference: bioRxiv, DOI: 10.1101/106955

Source: It only takes a few gene tweaks to make a human voice | New Scientist