Figuring out how to survive on 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, suggests research from Washington University in St. Louis.
"Challenges associated with finding food have long been recognized as important in shaping evolution of the brain and cognition in primates, including humans," said Amanda D. Melin, PhD, assistant professor of anthropology in Arts & Sciences and lead author of the study.
"Our work suggests that digging for insects when food was scarce may have contributed to hominid cognitive evolution and set the stage for advanced tool use."
Based on a five-year study of capuchin monkeys in Costa Rica, the research 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.
Published in the June 2014 Journal of Human Evolution, the study is the first to provide detailed evidence from the field on how seasonal changes in food supplies influence the foraging patterns of wild capuchin monkeys.
The study is co-authored by biologist Hilary C. Young and anthropologists Krisztina N. Mosdossy and Linda M. Fedigan, all from the University of Calgary, Canada.
It notes that many human populations also eat embedded insects on a seasonal basis and suggests that this practice played a key role in human evolution.
"We find 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," Melin said. "These results suggest embedded insects are an important fallback food."
|Contact: Gerry Everding|
Washington University in St. Louis