Modern language and speech can be traced back to our last common ancestors shared with Neanderthals some 500,000 year ago, according to scientists at the Max Planck Institute for Psycholinguistics.
Once thought to be capable of nothing more than grunts, Neanderthals were initially believed to be some form of subhuman brutes after evidence of them was discovered almost 200 years ago. A successful form of humanity that inhabited vast regions of western Eurasia for several hundreds of thousands of years, they lived during harsh ages and milder interglacial periods.
Current understanding places Neanderthals as our closest cousins with the likely candidate for our shared ancestor being Homo heidelbergensis, though for years it has remained unclear what their cognitive capacities were like or why modern humans succeeded in replacing them after thousands of years of cohabitation.
Recently, due to a number of discoveries and reassessments of old data, and especially as a result of the availability of ancient DNA, scientists are beginning to appreciate just how intertwined their fate was with modern humans', and that, far from being slow brutes, their cognitive capacities and culture were comparable to those today.
Researchers Dan Dediu and Stephen Levinson review all these strands of literature and argue that modern language and speech are an ancient feature of today's humanity dating back at least to the most recent ancestor we share with the Neanderthals and the Denisovans, another form of humanity known mostly from their genome.
This interpretation of the limited information available on the topic contradicts the scenario usually assumed by most language scientists of a sudden and recent emergence of modernity, presumably due to either a single or limited number of genetic mutations. Rather, the scientists argue that a gradual accumulation of biological as well as cultural innovations is much more likely.
In doing so, the researchers push back the origins of modern language by a factor of 10 from the oft-cited 50,000 years or so ago to around one million years ago between the origins of our genus, Homo, and the emergence of Homo heidelbergensis.
Given current understanding from the archaeological record and recent genetic data that the modern humans spreading out of Africa interacted with the Neanderthals and Denisovans, the scientists argue that it's possible that, in addition to our bodies carrying around some of their genes, today's languages preserve traces of theirs. If this is the case, at least some of observed linguistic diversity is due to these ancient encounters - a hypothesis that can be tested by comparing the structure of African and non-African languages and by detailed computer simulations of how languages spread.