Despite massive advances one question has boggled science: what made humans rise over other animals in the evolutionary process? It may be the fact that they could walk, says a father-son team of scientists at the University of Sydney in Australia.
Fascinated by the sight of their son and grandson learning to walk, the scientists probed the deepest depths of evolutionary science before concluding in their just published paper that bipedalism – or walking on two legs – is what set the human brain apart. “It liberated the cortex from the drudgery of controlling routine tasks and changed the human brain, making it smarter than that of any other animal,” they say.
Dr. Mac Shine, a neurology researcher at the University’s Brain and Mind Research Institute and his father, Rick Shine, Professor in Evolutionary Biology, describe the route they took to arrive at this conclusion in the journal Frontiers in Neuroscience.
Now 2 years old, Tyler Shine, was the inspiration behind the duo’s ideas. “We noticed how every step demanded the toddler’s entire attention when he was learning to walk,” they note. But once he gained balance and walking became routine, “the little boy was able to observe his surroundings and focus on more interesting tasks.” It was almost as if his mind had been “unburdened and liberated.”
Lockstep with Tyler’s improving gait, his capacity to observe the environment around him and to engage in mischief increased. It was as though the child was transferring the relatively menial chore of controlling his walk to “lower” parts of his brain and thereby releasing the cortex from routine, lower order processes. “Tyler was liberating the cortex for more challenging tasks, like dealing with unpredictable challenges such as obstacles.”
At first every new challenging task, be it driving a car or playing a new instrument, locks up the entire attention of its cortex. But eventually they become routine. “We shift such routinized tasks to the ‘lower’ areas of our brain like the basal ganglia and the cerebellum,” he explains. This is what makes humans smart; the fact that we are able to put routine tasks on auto mode and free up our most powerful mental faculties to deal with new, unpredictable challenges.”
The Shines propound in their paper that the shift from walking on all fours to doing so on two legs was key turning point in the early history of humans. It led to a change in the way we use our brains. When our pre-historic ancestors took their first bi-pedal steps they exposed not just their bodies but their brains to serious evolutionary stress. Dr. Shine says “all of a sudden the human brain was faced with the complex challenge of keeping balance.” It was a “massive neurocomputational challenge” to the brain, resulting eventually in the “rapid expansion of human cognitive capacity.”