According to palaeontologists at the Natural History Museum, the face holds the secret to determining the sex of our ancestors and what makes us attractive to the opposite sex for reproduction.
The study found that men have evolved short faces between the brow and upper lip, which highlights the size of their jaw, the flare of their cheeks and their eyebrows. The shorter and broader male face has also evolved alongside and the canine teeth have shrunk, so men look less threatening to competitors, yet attractive to mates.
The researchers claim that at puberty, the region between the mouth and eyebrows, known as upper facial height, develops differently in men and women. Unlike other facial features, however, this difference cannot be explained simply in terms of men being bigger than women.
In spite of their larger size men have an upper face similar in height to a female face, but much broader. These differences can be found throughout human history. As a result, a simple ratio of measures could be used to calculate facial attractiveness in a biological and mathematical way.
"The evolution of facial appearance is central to understanding what makes men and women attractive to each other. We have found the distance between the lip and brow was probably immensely important to what made us attractive in the past, as it does now," Dr Eleanor Weston, palaeontologist at the Natural History Museum said.
The findings of the study appear in the online, open-access journal PLoS ONE.