Facial complexity adapts to suit social demands in primates

Facial diversity may have evolved to aid primates in recognising and communicating with members of their own species, a new study has found.

Sharlene Santana, of the University of California, analysed the skin and hair patterns of 129 American primate species - creating a huge gallery of 'monkey mugshots'.

Analysis showed that the smaller the social groups a species lives in, the more complex their facial features.

Research suggests that facially complex monkeys, who have less contact with members of their own species and more with other species, depend more on facial patterns to recognise their peers.

Conversely, highly social animals living in large groups - for example apes or even humans - tend to have more plain facial features.

Santana's team believes this plainess allows facial expressions to be understood more easily, paving the way for the more complex communication we see in these species.

The published paper by Santana et al is published in The Proceedings of the Royal Society B: Biological Sciences: Adaptive evolution of facial colour patterns in Neotropical primates

A full article, including an interview with Dr Santana, can be found here: Funny Facial Features Tell Monkeys Who's Who