Scientific study shows how jaws evolved

By Joe Morgan via SWNS

Jaws evolved to their peak in evolution more than 400 million years ago, according to new research.

Humans owe their evolutionary success to the ability to bite using both strength and speed with a variety of foods, but each creature has evolved its own way.

The fastest on Earth is the trap-jaw ant which closes its jaws at 78 to 145 miles per hour - 2,300 times faster than a blink of an eye.

The strongest are saltwater crocodiles which can slam their jaws shut at 16,460 newtons of bite force - over 30 times more powerful than a human's.

Jaws evolved from the gill arches, a series of structures in fish that support their gills.

In the study published in Science Advances, British researchers show how a breathing structure came to be used for biting and evolved extremely quickly to its optimum shape and size.

Data models show how even if the earliest creatures had focused more on speed than strength in their jaws, they were more likely to break.

So human ancestors had to evolve to find the optimal way for jaws to be both strong and speedy.

Comparing the real and theoretical jaw shapes revealed that jaw evolution has been constrained to shapes that have the highest possible speed and strength.

Specifically, the earliest jaws in the dataset were extremely optimal, and some groups evolved away from this optimum over time.

These results suggest that the evolution of biting was very quick.

William Deakin, a Ph.D. student at the University of Bristol and lead author, said: “Jaws are an extremely important feature to gnathostomes – or jaw-mouths.

"They are not only extremely widespread, but almost all creatures that have them, use them in the same way – to grab food and process it.

"That’s more than can be said for an arm or a foot or a tail, which can be used for all sorts of things.

“This makes jaws extremely useful to anyone studying the evolution of function.

"Very different jaws from very different animals can be tested in similar ways.

"Here we have shown that studies on a large variety of jaws, using theoretical morphology and adaptive landscapes to capture their variety in function, can help shed some light on evolutionary questions.”

Professor Philip Donoghue, the co-author, said: “The earliest jawed vertebrates have jaws in all shapes and sizes, long thought to reflect adaptation to different functions.

"Our study shows that most of this variation was equally optimal for strength and speed, making for fearsome predators.”

Professor Emily Rayfield, also a co-author said they plan to use the new software to "uncover many more of the secrets of evolutionary history.”