Millions of years ago, early humans transitioned from forests to grasslands in Africa, seeking new food sources. Recent research suggests that they learned to consume grasses, including grains and underground organs, thousands of years before their teeth had transformed to eat them effectively.
According to a study published in Science, hominins’ behavioral adaptations led to physical changes through the process of “behavioral drive.” This means that they adapted to their new environment through diet changes before their teeth evolved. The researchers analyzed carbon and oxygen isotopes on the teeth of hominins and other primates, revealing that humans switched to grasses around 3.8 million years ago.
The shift from above-ground to underground grasses was advantageous for humans, providing more nutrients with less effort. It’s believed that this change created a reliable food source, allowing ancestors to access carbs throughout the year. The study suggests that humans’ ability to exploit grass tissues may be their key advantage over other primates.
“This work shows that the ability to exploit grass tissues may be our secret sauce,” said Nathaniel Dominy, a study author and Dartmouth College professor.
Source: https://www.discovermagazine.com/our-ancient-ancestors-loved-eating-grasses-and-it-eventually-transformed-47875