Early humans may have started using language for communication over 100,000 years ago, a new review of genomic data shows.
There are some 7,000 identified languages spoken globally, and researchers say they all have a common origin back when early human groups started spreading across the world.
Our ancestors developed the cognitive ability for language, combining vocabulary and grammar into a system of expression, over millions of years of evolution.
The capacity to talk in humans first appeared at least 135,000 years ago, more than 100,000 years after the species first emerged in Africa.
The new review, detailed in the journal Frontiers in Psychology, examines over a dozen genetic studies published in the past 18 years to indicate an initial branching of humans about 135,000 years ago.
After groups of early humans went apart geographically, each subpopulation developed genetic variations. “Every population branching across the globe has human language and all languages are related,” study co-author Shigeru Miyagawa, from the Massachusetts Institute of Technology in the US, said.
“I think we can say with a fair amount of certainty that the first split occurred about 135,000 years ago, so human language capacity must have been present by then, or before,” Dr Miyagawa explained.
The 15 genome studies reviewed in the current research collectively point to when the first geographic splits started taking place.
By analysing the genetic variations explained in the studies, the researchers could estimate the point in time at which Homo sapiens was still a single regionally undivided group. They say the data points to some 135,000 years ago as the likely time of the first split.
“Recent genome-level studies on the divergence of early Homo sapiens, based on single nucleotide polymorphisms, suggest that the initial population division within H sapiens from the original stem occurred approximately 135 thousand years ago,” they say.
Since all subsequent spread of human groups led to populations with full language capacity, scientists suspect the potential for language as a communication tool was present at the latest around 135,000 years ago, before the first division occurred.
“Had linguistic capacity developed later, we would expect to find some modern human populations without language or with some fundamentally different mode of communication. Neither is the case,” the researchers conclude. “Based on the lower boundary of 135,000 years ago for language, we propose that language may have triggered the widespread appearance of modern human behavior approximately 100,000 years ago.”
