Dr. Stephen Cunnane, a metabolic physiologist at the University of Sherbrooke, Quebec said that it was a rich and secure shore-based diet that fuelled and provided the essential nutrients to make our brains what they are today. Early hominid brains underwent the process of brain expansion by eating clams, frogs, bird eggs and fish from shoreline environments. This is what that led to the explosive brain growth. Our brains weigh roughly twice as much as the earliest human relative. Dr. Cunnane talks about the substances needed that are critical for healthy human brain development.
He says that an average newborn's human brain consumes about 75% of an infant's daily energy needs. Hence human babies are born with a built-in energy reservoir called the baby fat. Human infants are the only primate babies born with excess fat. It accounts for about 14 % of their birth weight, similar to that of their brains.
This baby fat helped in providing the physiological conditions for man's evolutionary brain expansion. These fat reservoirs are due to the result of their moms dining on shoreline delicacies like clams and catfish. The author said that his hypothesis the fittest early humans were those with the fattest infants was due to this reason. He has also elaborated on this in his book Survival of the Fattest which was published in 2005.
The environments found in the wetlands, river, and lake shorelines were dominated in east Africa's prehistoric Rift Valley in which the early humans evolved. This was supported by Dr. Kathy Stewart from the Canadian Museum of Nature, in Ottawa. Her study of fossil material excavated from the sites in eastern Africa revealed a bevy of chewed fish bones, particularly catfish.
Brain development and function requires polyunsaturated fatty acid docosahexaenoic acid (DHA). DHA is critical to proper neuron function. Human baby fat provides both the energy source for the rapidly growing infant grey matter and a greater concentration of DHA. Sea food is also rich in iodine which is a key brain nutrient. The genetic possibility remained silent until it was catalyzed by this shore-based diet.
He also compares it with the present day situation and the importance of key shoreline nutrients to brain development. He says that iodine deficiency is the world's leading nutrient deficiency affecting more than 1.5 billion people, mostly in inland areas. But now to prevent it Iodine is legally required to be added to salt in more than 100 countries. By this way we have created an artificial shore-based food supply.