A lean-season diet of hard-to-reach ants, slugs and other bugs may have spurred the development of bigger brains and higher-level cognitive functions in the ancestors of humans and other primates, reveals a new study.
According to the study by Washington University, challenges associated with finding food have long been recognized as important in shaping evolution of the brain and cognition in primates, including humans.
Amanda D. Melin said that the study suggests that digging for insects when food was scarce may have contributed to hominid cognitive evolution and set the stage for advanced tool use.
The study provides support for an evolutionary theory that links the development of sensorimotor (SMI) skills, such as increased manual dexterity, tool use, and innovative problem solving, to the creative challenges of foraging for insects and other foods that are buried, embedded or otherwise hard to procure.
Melin added that they have found that capuchin monkeys eat embedded insects year-round but intensify their feeding seasonally, during the time that their preferred food - ripe fruit - is less abundant.
The findings suggest that the ingenuity required to survive on a diet of elusive insects has been a key factor in the development of uniquely human skills.
The study was published in the Journal of Human Evolution.