Joel Kontinen
Once upon a time, some evolutionists used to believe that our brain was basically made up of three parts, viz. the reptilian, the paleomammalian and the neomammalian, that were tinkered together by evolution.
Physician and neuroscientist Paul D. MacLean proposed this hypothesis in the 1960s and explained it at length in his book The Triune Brain in Evolution (1990).
Carl Sagan, for instance, popularised this view. Time magazine claimed in 2008 that fear “is embedded by evolution in our lizard brain.”
MacLean’s hypothesis has long since fallen out of favour. Neuroscientists have begun to see the human brain as a wonderful organ. Some have likened it to a well-organised library. Research suggests that our brains may be designed to help us learn rapidly.
The human brain even inspires engineers to build smarter computers.
New research published in the journal Neuron attempts to explain why our brains are so fast. Science Daily summarises the findings:
“Surprisingly complex interactions between neurotransmitter receptors and other key proteins help explain the brain's ability to process information with lightning speed, according to a new study. Scientists combined experimental techniques to examine fast-acting protein macromolecules, known as AMPA receptors, which are a major player in brain signaling.”
The results suggest something that is a far cry from the three-part brain hypothesis:
" ‘The findings reveal that the interplay between AMPA receptors and their protein partners that modulate them is much more complex than previously thought,’ says lead researcher Derek Bowie, a professor of pharmacology at McGill and Director of GÉPROM, a Quebec interuniversity research group that studies the function and role of membrane proteins in health and disease.”
For all intents and purposes, our brain looks like it was superbly designed. Its size remains a Darwinian dilemma, and its complexity and effectiveness challenge evolutionary explanations.
Source:
McGill University. 2016. What makes the brain tick so fast? New study sheds light on the workings of brain neurotransmitter receptors. Science Daily. (25 February).
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