How Ancient Primates’ Sweet Tooth Might Have Shaped Human Evolution
Monkeys and apes, including humans, have been noshing on fruits for thousands of years – and new research is giving fascinating insights into how this sugary fare may have shaped our evolution.
A study of fossilized primate teeth dating back 29 to 35 million years ago shows just a handful of chips and fractures, suggesting these primates more often feasted on easy-to-chew fruit rather than hard objects like nuts or seeds that would otherwise cause wear to their teeth.
What’s more, two of the fossils, belonging to Propliopithecus individuals, showed telltale tooth decay, a sign they were especially fond of sweet fruits.
Exploring Our Primate Ancestors’ Diets
The findings, published in The American Journal of Biological Anthropology, involved analyzing more than 400 teeth from five species – specifically Propliopithecus, Apidium and Aegyptopithecus. By examining the fractured teeth, researchers were able to deduce these primates weren’t chowing down on hard foods like nuts or seeds.
In fact, the findings showed tooth damage was around 5% – much lower than the 4 to 40% food damage typically seen in living primates species.
Species like the sooty mangabey, who feed on hard food, may have fractures on up to half of their teeth, while primates who mostly eat soft food like fruits or insects have much less than 10% of their teeth chipped.
Dietary Changes Throughout Human Evolution
The data provides interesting insights into human evolution and dietary changes over the years. The fossils are from a time when the last common ancestor of primates, including humans, and African and Asian monkeys still existed.
“It gives insight into our own evolution, our own dietary changes through time,” says Ian Towle, a dental anthropologist at Centro Nacional de Investigación sobre la Evolución Humana in Burgos, Spain.
And the presence of cavities in fossil teeth even suggests the taste for (or addiction to?) sweetness may be deep-rooted. The study also provides a clue as to why monkey and ape diets didn’t diversify to include harder food like nuts and seeds until later.
Not An Open-and-Shut Case
However, other studies examining tooth shape and wear point to some of the analyzed genera as having diets based more around hard items, rather than fruit, suggesting there’s still more to uncover in the area.
Towle and his colleagues point to a need for a multi-faceted approach to getting to the bottom of the questions around primate diets.
With further research, it may be possible to pinpoint how much of ancient primates’ diets were made up of soft foods like fruit and when exactly a taste for harder food like nuts and seeds emerged.
Until then, the mystery around our early ancestors’ diets may remain – hidden deep within their fossilized teeth.
