Wild Calls of Bonobo Apes Sound Simple, but Scientists Find Striking Similarities With Human Language
The evolution of human language has been closely examined and analyzed by researchers for decades. Experts have traced language's growth and diversity in societies and have also had findings indicating that the feature was present even in our ancestors. The ancestors produced many species that also carried different variants of this feature, stated IFL Science. The language capabilities of one of the human relatives have been discussed in Science.
The study's subject was bonobos, whose DNA is 98.8 percent similar to humans. Researchers claim that the language of bonobos and humans has certain structural similarities. Experts noted that these creatures communicated through high-pitched calls. These calls included loud whistles reverberating through jungles, while some are low in volume. These sounds are distinct from chimpanzees, who also share a common ancestor with humans and bonobos. Researchers determined that bonobos' calls were an octave higher than chimpanzees'.
Scientists from the University of Zürich and Harvard University analyzed 700 recordings of bonobo calls from the Kokolopori Bonobo Reserve in the Democratic Republic of the Congo. The calls were categorized from "peeps" and "whistles" to "grunts" and "yelps." Experts detected many qualities that are also present in human language. Researchers were ecstatic to find these common features, stated SciAm. "That’s really exciting," co-senior author Simon Townsend, who studies comparative communication at the University of Zurich, said. "It allows us to go back in time and work out what our last common ancestor, who was living seven million years ago in the forests of Africa, was doing."
In total, the team identified 300 contextual features in these calls, stated IFL Science. A noteworthy aspect that was observed in the bonobo calls was compositionality, the capability of combining certain call types into different structures. In humans, compositionality works in two ways—trivial and nontrivial.
Trivial compositionality involves terminologies in which each word retains its independent meaning. 'Blue Circle' contains two words that do not impact each other's meanings. Blue remains a color even without the circle, while a circle remains a shape even without the color. Non-trivial ones, on the other hand, refer to terminologies that contain words that impact each other's meanings. 'Bad Dancer' is an example where bad is a quality that describes a particular dancer. If the bad word is removed, the terminology does not refer to that particular dancer anymore. Such features provide human language flexibility.
The scientists detected this feature in the bonobo calls. Researchers claim that different sounds come together in four compositional structures in bonobo calls. Three of them seem to be non-trivial by nature. Researchers are hopeful that more analysis of bonobo calls will give further insights into the evolution of language. Experts think that there could be other groups of species with compositionality, though he is less positive about its presence in nonprimates, SciAm stated. "We don’t know yet if bonobos are special," lead author Mélissa Berthet, a postdoctoral researcher in Townsend’s group, said. "We developed this method, we used it on bonobos, and we found very cool results. But maybe you could do that on other animals."