Every so often, when pondering the big things in life – such as one sugar or two, that kind of thing – we’re known to stroke our chin in a contemplative manner. This got us thinking; why do we (as in humans) have chins when they’re conspicuous by their absence on other animals?

The answer appears to be down to something we all love: Cooking.

Originally it was believed that we have chins because of some sort of genetic deviation that stuck, or, perhaps more plausibly, our predecessors were biologically rigged to associate a prominent jaw line with a strong libido – a peacock’s tail for humankind, if you like.

However new research that has come to light out of the University of Florida appears to suggest that the chin firs began to appear around the time that humans began to cook and eat softer food stuffs.

The shift in our diet removed the need for big teeth and huge, primate-like jaws and so, over a very long period of time, the chin was born. In evolutionary terms, this is known as a spandrel event – the by-product of the evolution of another, yet linked, characteristic.

“We give natural selection too much credit,” said Dr Pampush, an evolutionary anthropologist who led the investigation.

“Natural selection is the most important part of the history of life, but it’s not the overwhelmingly powerful sculpting force that so many think it is. Chance events need to be given more attention.”

Pampush continued, bringing up the difference between Homo sapiens and Homo erectus: “We had a soft diet, and we no longer needed big teeth. Homo erectus had a larger body size, much larger brains, was probably cooking and there’s a good chance they were using clothing. They were very human-like, but had no chins,” he continued.

“I’m guessing the changes that ultimately lead to the chin are directly related to cooking, and indirectly relate.”

The full study, entitled ‘Selection played a role in the evolution of the human chin’ is available in the latest issue of the Journal of Human Evolution.