When apes hang out their vocabularies change, just like humans’, and it takes just a single social interaction to shape these animals’ distinct “vocal personalities”. That’s the pivotal finding from a new study led by researchers from the University of Warwick, who say their findings are a breakthrough in understanding the evolution of language.
This new research, published in the journal Nature Ecology and Evolution, looked at social mingling among 70 orangutans across six populations in Borneo and Sumatra, Southeast Asia. Here, study lead Dr Adriano R Lameira and colleagues lived alongside the apes, enabling them to record calls and gather the largest ever sample of vocal recordings of this kind for scientific research.
Their mega playlist of orangutan interactions and vocalizations revealed that dense populations were home to more vocabulary experimentation and diversity, seeing animals use a wide range of original calls remixed with novel sounds that could endure or be dropped.
Conversely, small populations living in a more spread-out arrangement tended to stick to a smaller range of tried and tested calls. While there was less experimentation with new sounds in these sparse groups, novel noises tended to stick once they were introduced. This meant an individual’s complete repertoire was actually richer compared to that of the densely-packed orangutans who would regularly ditch new sounds.
For language to evolve, it’s possible that social influence must exist as a means of agreeing upon a fixed standard of communication within a population in order for vocal norms to become operational. As such, establishing at what point in our evolutionary history apes began paying attention to and being influenced by the vocalizations of other individuals is a crucial stepping stone in understanding how language began.
Orangutans exhibit “vocal personalities,” the authors conclude, which – like humans – can be shaped and influenced by interactions with other orangutans. As such, they represent an intermediate step in the journey from vocalizations to language among great apes.
“We can now start conceiving of a gradual path that likely led to the rise of the talking ape, us, instead of having to attribute our unique verbal skills and advanced cognition to divine intervention or random genetic jackpot.”
While a fascinating insight into the growing sophistication of communication among our closest relatives, the authors believe the research is also a clear demonstration of what we stand to lose if more isn’t done to protect our living ancestors.
“Many more clues await us in the lives of our closest living relatives, as long as we manage to guarantee their protection and their preservation in the wild,” Lameira concluded.
“Each disappearing population will take with it unretrievable glimpses of the evolutionary history of our species.”