TUESDAY, 7 SEPTEMBER 2021
Our faces are vital for distinguishing between individuals and social communication — studying their evolution can therefore tell us a lot about human development.
In 1926, German anthropologist Adolf Naef commented on the remarkable similarity between the human face and that of a baby chimpanzee’s, saying ‘[It] is the most human-like picture of an animal, of any that is known to me’. Although adult chimpanzees can be distinguished by a small cranium and protruded jaw, the structure of a baby chimpanzee’s face demonstrates their close evolutionary relationship with humans.
This observation in humans is an example of neoteny — where traits seem to develop in the same way as chimpanzees, but stop earlier. It causes adult features, such as the flat, hairless face, to appear more juvenile, resembling infants in other primate species.
Many evolutionary biologists consider neoteny a key feature in human evolution, given how it varies across primate and early human species, and its link to a longer developmental duration before adulthood. Potential factors that have contributed towards this protracted development period include diet, speech, non-verbal communication, and even climate. Understanding the history of the human face not only provides clues about how humans evolved as a species, it may even hint at how our faces could change in the future.
Written by Hannah Lin. Image from http://arc-team-open-research.blogspot.com/2014/07/makehuman-tests-with-facial.html