The face: it’s personal, yet universal. It’s how we recognize each other and communicate our emotions—and yet there’s more to it than immediately meets the eye. Beneath the skin and muscles that form our smirks and scowls are 14 different bones that house parts of the digestive, respiratory, visual, and olfactory systems—enabling us to sniffle, chew, blink, and much more.
Thanks to the discovery of fossils, researchers are able to observe how faces have evolved over time, from extinct hominin species walking the Earth millions of years ago, to Neanderthals, to the only remaining hominin species—Homo sapiens, or humans.
Scientists in a new study have suggested that the evolution of the human face may have been partly driven by our need for good social skills. The study authored by a team of international experts, including researchers from the University of York, traces changes in the evolution of the face from the early African hominins to the appearance of modern human anatomy.
According to scientists, human faces evolved not only due to factors such as diet and climate, but possibly also to provide more opportunities for the gesture and nonverbal communication.
Paul O’Higgins, Professor of Anatomy at the Hull York Medical School and the Department of Archaeology at the University of York said, “We can now use our faces to signal more than 20 different categories of emotion via the contraction or relaxation of muscles. It’s unlikely that our early human ancestors had the same facial dexterity as the overall shape of the face and the positions of the muscles were different.”
Instead of the pronounced brow ridge of other hominins, humans developed a smooth forehead with more visible, hairy eyebrows capable of a greater range of movement. This, alongside our faces becoming more slender, allows us to express a wide range of subtle emotions – including recognition and sympathy.
Professor O’Higgins said, “We know that other factors such as diet, respiratory physiology, and climate have contributed to the shape of the modern human face, but to interpret its evolution solely in terms of these factors would be an oversimplification.”
The human face has been partly formed by the mechanical demands of feeding and in the past 100,00 years our faces have been getting smaller as our developing capacity to prepare and process food prompted a diminished requirement for biting.
This facial shrinking process has become particularly marked since the agricultural revolution, as we switched from being hunter-gatherers to agriculturalists and then to living in cities – lifestyles that led to increasingly pre-processed foods and less physical effort.
Professor O’Higgins said, “Softer modern diets and industrialized societies may mean that the human face continues to decrease in size. There are limits on how much the human face can change however, for example, breathing requires a sufficiently large nasal cavity.”
“However, within these limits, the evolution of the human face is likely to continue as long as our species survives, migrates and encounters new environmental, social and cultural conditions.”
A new review published in Nature Ecology and Evolution.