That we humans have descended from apes has now been confirmed through DNA-based genetic analysis. That the origin of species and their evolution over time, suggested about 160 years ago by Charles Darwin, is now widely accepted through there is a tiny group of religion-based Darwin-deniers. Recall the “Great Oxford Debate” of 1860 wherein Bishop Wilberforce of Oxford taunted Dr Thomas Huxley (who defended Darwin’s theory, on behalf of Darwin who was sick) asking: “Is it through your grandfather or grandmother that you claim your descent for an ape”? Huxley responded calmly: “A man has no reason to be ashamed of having an ape for his grandfather. If there was an ancestor whom I should feel shame in recalling, it would be a man, a man of vastness and versatile intellect, who, not content with success in his own sphere of activity, plunges into scientific questions with which he has no real acquaintance, only to obscure them by an aimless rhetoric and distract the attention of his hearers from the real point at issue by eloquent digression and skilled appeal to religious prejudice”. (Source: darwinday.org).
Huxley’s response is quoted here not only for the spontaneity, brilliance, calm rejoinder and choice of words, but also because of its contemporary relevance today.
Inherited gestures
That not only our genetic and biochemical functions are a result of our descent from apes (including the gorilla, orangutan, chimpanzee and bonabo), but even our gestures in communication might be. This has been suggested in a recent research paper that has appeared in the journal Animal Cognition (V. Kersken et al. issue of September 8, 2018;https://doi.org/10.1007/&10071-08-1213, free on the web) The authors point out: “great apes of all species — human and non-human — communicate using a combination of different types of signals: vocalisation, gestures, facial expressions, body pastures, and even cues from colour: such as blushing, or odour, can transmit information between individuals. In humans, however, language (whether spoken or signed) appears to represent a fundamentally distinct system of communication…” In contrast great apes do not have a spoken language, yet they have a large repertoire over 60 different gesture types as signals, which they use to communicate every day goals. They display these both flexibly and intentionally: further, these are seen to be common and across all species of apes. This has lead to the conclusion that this set of 60 plus gestures that great apes use among and between themselves is a non-human system of communication. It has also been suggested that human language may have originated from this “gestural domain”. Professor Michael Tomasello of the Max Planck Institute of Evolutionary Anthropology at Leipzig has published a book titled “Origins of Human Communication” (M.I.T .Press 2018). Dr Hewes and coauthors had earlier published a paper in 1973 titled “Primate communication and the gestural origin of language” ( Current Anthropology, 14: 5-24). And more recently, Hobaiter and Byrne have provided a “lexicon” of the meaning of chimpanzee gestures ( Current Biology 2014, 24:1596-1600).
Human infants
Let us now turn to our own human infants. Our infants take time to learn spoken language. A typical human infant uses a variety of gestures until the age of 1 or 2 as means of communication with adults and amongst them, before learning and using spoken language. What and how many gestures do human infants (who are yet to learn and speak a language) use , and how many of these gestures are common to those used by the great apes? A comparative study of these has been done by an international group from Scotland, Uganda, Germany and Switzerland led by Dr. Catherine Hobaiter of Scotland, which has appeared in a special issue on “Evolving the Study of Gesture” in the journal Animal Cognition mentioned above.
The group recorded the gestures of 7 children of 315-421 days of age in Uganda, under natural settings, as well as 6 children aged 343-642 days in Germany also in their natural setting. They recorded all the gestures these infants used to communicate with, and found they employed 52 distinct gestures. In comparison, they had analysed the gestures used by chimpanzees aged between 12 months old to 51 years old. Remarkably, they found that children used 52 distinct gestures, and of these 46 are also present in the chimpanzee repertoire! As the authors note: “like chimpanzees, human infants used the gestures both singly, and in sequences, and employed individual gestures flexibly towards different goals”.
What are some of these gestures common to human infants and chimpanzees? Raising the arm, shaking it, grabbing the other individual’s body, hitting the other party, reaching out to the palm of the other, stomping and stomping rhythmically, throwing an object, touching the other person’s hands or fingers and so forth. All these were not random, but each carried a message and had a meaning. However, some gestures such as waving a hand to greet or to say good bye was seen in human infants and not in the apes. And human toddlers pointed out a lot more than the chimps. But the fact that children employed 89% of gestures common to them and to chimpanzees argues for a common evolutionary heritage.
As Naia Carlos writes in her Nature World News column of September 13, 2018, the team of authors is recommending further studies on a larger set of children as well as the inclusion of other apes such as bonabos, who are said to be an even closer relative to humans than chimpanzees. We seem to have gotten our gestures and languages from the apes, and the reach of DNA appears to be beyond simple physiological evolution into the origin of communication and language.
dbala@lvpei.org
