Ancient humans adapted to tough diets through behavioral changes before physical evolution

Ancient human ancestors began consuming tough grasses and underground plant parts long before their dental structures evolved to process such foods effectively. A recent study conducted by researchers at Dartmouth University, published in Science, reveals that behavioral adaptations played a crucial role in human evolution, predating physical changes. As early humans transitioned from forested environments to open grassy plains, they sought reliable energy sources like grains and underground tubers, which are rich in carbohydrates. Despite their teeth not being initially suited for such fibrous foods, these dietary choices persisted and supported survival. Analysis of fossilized teeth from hominin species dating back nearly 5 million years demonstrated chemical signatures indicating consumption of grasses and sedges—collectively known as graminoids. This suggests early dietary habits included these plants, driven by behavioral flexibility. Lead researcher Luke Fannin explains that this illustrates a concept called 'behavioral drive,' where changes in diet and habits occurred in response to environmental challenges even before physical adaptations took place. This adaptability al...