Big Brains from Bugs?
Foraging for food and the challenges that come with it has been recognized as important in shaping brain evolution in primates. New research from Washington University in St. Louis suggests that having to figure out how to survive on difficult to find bugs in the ground and forest could have helped us develop bigger brains and higher cognitive functions, mainly due to both the innovation needed to find the bugs and the nutrition of the bugs themselves.
Food sources change with the seasons, and lean-season diets require more thought around how to find nutrition. Primates, including our ancestors, generally survive on a diet of fruits and other easy to obtain edible plants. However, when fruits are scarce, primates have to depend on other sources, namely bugs. The WU study is based on 5 years of research on capuchin monkeys in Costa Rica, and finds that seasonal changes in food supply influences foraging patterns of the monkeys. Even though the monkeys eat hard to find insects year-round, they go through seasonal cycles depending on when ripe fruit is abundant or not, making insects a fall-back food.
Evolution of strong jaws, thick teeth, and specialized digestive systems has already been shown to be influenced by the fall-back foods of primates. Now, this research shows these fall-back foods have been important in shaping the brain and higher cognition as well. Essentially, having to come up with innovative tools and methods to access well-hidden bugs developed larger and more complex brains, which then are fueled by the high-quality fat and protein in the bugs. Presently, there are cultures that still rely on insects as an additional food source. Maybe we should all help our brains with this old snack.