According to Dr. Stephen Cunnane it was a rich and secure shore-based diet that fuelled and provided the essential nutrients to make our brains what they are today. Controversially, according to Dr. Cunnane our initial brain boost didn't happen by adaptation, but by exaptation, or chance.
"Anthropologists and evolutionary biologists usually point to things like the rise of language and tool making to explain the massive expansion of early hominid brains. But this is a Catch-22. Something had to start the process of brain expansion and I think it was early humans eating clams, frogs, bird eggs and fish from shoreline environments. This is what created the necessary physiological conditions for explosive brain growth," says Dr. Cunnane, a metabolic physiologist at the University of Sherbrooke in Sherbrooke, Quebec.
The evolutionary growth in hominid brain size remains a mystery and a major point of contention among anthropologists. Our brains weigh roughly twice as much as our similarly sized earliest human relative, Homo habilis two million years ago. The big question is which came first ?the bigger brain or the social, linguistic and tool-making skills we associate with it?
But, Dr. Cunnane argues that most anthropologists are ignorant or dismissive of the key missing link to help answer this question: the metabolic constraints that are critical for healthy human brain development today, and for its evolution.
Human brains aren't just comparatively big, they're hungry. The average newborn's brain consumes an amazing 75-per cent of an infant's daily energy needs. According to Dr. Cunnane, to fuel this neural demand, human babies are born with a built-in energy reservoir ?that cute baby fat. Human infants are the only primate babies
Source:Natural Sciences and Engineering Research Council