Led by Eörs Szathmáry, academician and research professor at the Institute of Evolution of the ELKH Centre for Ecological Research (CER), researchers have used computer simulations to model the evolutionary development of pre-linguistic proto-linguistic ability. Their findings indicate that the proto-language may have emerged nearly two million years ago during group hunts of large animals' remains. The research results have been published in Philosophical Transactions of the Royal Society B, one of the world's oldest and most prestigious scientific journals. Notably, the latest issue of the publication, which focuses on major transitions in human evolution, was partially edited by Eörs Szathmáry.
As the process of becoming human is commonly believed to be closely related to the development of modern human language, the evolution of language has long been one of the most important areas of scientific research into the phylogenesis of human ancestors. According to one theory, a pre- or proto-language that preceded human language may have emerged as far back as two million years ago, during the era of Homo erectus, i.e. more than one and a half million years before the appearance of Homo sapiens. The emergence of this proto-language might have been indirectly influenced by the climate change of the time.
What might this proto-language have been like and how did it differ from fully developed human language? It likely had an acoustic component and also included gestures. These gestures, such as pointing to objects or mimicking their physical appearance, may have aided in the comprehension of information conveyed through acoustic means. At that time, vocal signals were not yet strung together according to specific rules, but as we know from psychological experiments, it is possible to communicate quite effectively with just a few words, as we can see in chat messages, for example. However, a grammar that creates more complex semantic connections between spoken words could have emerged only in Homo sapiens, which can be regarded as the actual formation of language. Therefore, the lack of grammar distinguishes the pre-language from the latter.
"About two million years ago, the climate became much drier, which caused a decline in food sources for Homo erectus. Since their weapons were not yet advanced, they were unable to hunt large animals and could only consume the remains of dead animals. So the Homo erectus partially turned to scavenging, but in this area, they had to compete with dangerous predators that also could not usually take down adult large animals – such as elephants, rhinos, and hippos – so they also relied on carrion. We began this current work a decade ago together with the since-deceased renowned linguist Derek Bickerton, whose theory held that this 'confrontational scavenging' forced communication among members of Homo erectus groups, giving them an advantage against predators through more efficient collaboration," explained Eörs Szathmáry.
While predatory animals were unable to break the skin of the largest animals and had to wait for it to split due to decay, Homo erectus already had tools that could cut through the skin and muscles of carcasses. Predators undoubtedly attempted to steal the carcasses from them, but the Homo erectus were numerous, collaborated with each other, and defended their lives, thus tipping the balance increasingly in their favor.
The proto-language may have played an important role in their success. Interestingly, the communication of bees also evolved in connection with feeding. Homo erectus already had a brain size that was quite large compared to their body mass, which provided a suitable basis for the evolution of increasingly complex cognitive abilities, including the development of proto-language.
The evolutionary biologists at CER simulated this presumed process using a computer, and according to their results, there is no energetic obstacle to the idea that cooperative scavenging was the main driving force behind the development of proto-language. "From the models, we see that the confrontational scavenging and the proto-language may have emerged abruptly and almost simultaneously during human evolution. Of course, we cannot literally prove evolutionary events that took place millions of years ago. However, if we thoroughly investigate a transition and exclude most of the possible scenarios, what remains is increasingly likely to accurately describe the real events,” explained Eörs Szathmáry.