#selective pressure

Eyebrow Raising

Although humans have lost most of the hair from their bodies and faces over many thousands of years of evolution, we have kept a few distinctive patches. One example is eyebrows, which are thought to be important not only for keeping sweat out of our eyes but also for communication and even sexual attraction. Eyebrow thickness varies from person to person – as seen in these three examples – and it appears to be something you inherit from your parents, suggesting that it is strongly controlled by genes. Researchers have now used careful genetic analysis to pinpoint a number of variations in ‘control switches’ in DNA, which affect eyebrow thickness in people from a wide range of ethnic groups by altering the activity of genes involved in hair growth. But they found no evidence that these variations were under strong sexual selection pressure, suggesting that eyebrow thickness has no impact on attractiveness.

Written by Kat Arney

Image adapted from work by Sijie Wu, Manfei Zhang and Xinzhou Yang, and colleagues

Shanghai Institutes for Biological Sciences, Shanghai, China

Image originally published under a Creative Commons Licence (BY 4.0)

Published in PLOS Genetics, September 2018

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