CANADA: A rich diet of clams and catfish helped make modern humans what we are today. An ample supply of easy to reach shoreline delicacies helped to make fat infants and fat infants were able to grow bigger brains, a Canadian researcher argues.
A metabolic physiologist at the University of Sherbrooke, Quebec, believes the high protein diet available to our early human ancestors two million years ago launched us onto the path of big-brained dominance.
"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," said Dr Stephen Cunnane. "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."
He discussed his controversial views over the weekend at the American Association for the Advancement of Science annual meeting, which concludes later today in St Louis. Most expert opinion favours the view that the development of language and tool use provided the spark that triggered the growth of our larger brains.
Not so says Dr Cunnane, who argues that plenty of rich food was required to allow this energy hungry organ to grow.
Our brains weigh twice as much as our similarly sized earliest human relative, Homo Habilis.
The question for evolutionary biologists is what came first, the bigger brain or the social and linguistic skills.
The food supply had to be there first, Dr Cunnane believes. A newborn's brain consumes an amazing 75 per cent of an infant's daily energy needs. To meet this huge demand, modern human babies are born with a ready-made, built-in energy reservoir, their cuddly baby fat.
Humans are the only primates born with excess fat, which amounts to no less than 14 per cent of the newborn's weight. It is this baby fat that provided the physiological conditions necessary for hominids' evolutionary brain expansion, Dr Cunnane believes.
And these ancestral babies were able to pack on the pounds because their mothers were busy dining out on the rich pickings found along the lakes and streams in Africa's Rift Valley where our kind originally developed.
Succulent clams and protein-laden fish were the brain foods that in time allowed Homo Sapiens to dominate the world.
