29268910YNH Homo Sapiens: the cost of thinking ed.

Q&@
DESPITE THEIR MANY
DIFFERENCES, ALL HUMAN SPECIES SHARE SEVERAL DEFINING
CHARACTERISTICS. MOST NOTABLY, HUMANS HAVE EXTRAORDINARILY
LARGE BRAINS COMPARED TO OTHER OTHER ANIMALS. MAMMALS WEIGHING ABOUT 60 KILOGRAMS
HAVE AN AVERAGE BRAIN SIZE OF 200 CUBIC CENTIMETRES?! The earliest men and women, 2,5 million years
ago, had brains of about 600 cubic centimetres & modern sapients sport a brain averaging 1200-1400 cubic centi-
metres. Neanderthal brains were even bigger. That evolution should select for larger brains may seem to us like, well,
a no-brainer. We are só enamoured of our high intelligence that we assume that when it comes to cerebral power,
móre MÙST bé bètter?! But ìf thàt were the case, the feline family would also have produced cats who could do cal-
culus and frogs would by now have launched their own space programme! Why are giant brains so rare in the animal
kingdom? The fact is that a jumbo brain is a jumbo drain on the body. It's nòt easy to carry around, especially when
encased inside a massive skull! It's even harder to fuel. In homo sapiens, the brain accounts for about 2-3% of total
body weight, but it consumes 25% of the body's energy when our body is at rest. By comparison, the brains of
other apes require only 8% of rest-time energy. Archaic humans paid for their large brains in two ways. Firstly,
they spent more time in search of food. Secondly, their muscles atrophied. Like a government diverting money
from defense to education, humans diverted from biceps to neurons. It's hardly a foregone conclusion that this
ìs a góód strategy for survival on the savannah. A chimpanzee can't wìn an argument with a Homo sapiens,
but an ape càn rìp the man apart like a rag doll! Today our big brains pay off nicely, because we can produce
cars and guns that enable us to move much more faster that chimps, and shoot them from a safe distance
instead of a wrestling match. But cars and guns are a recent phenomenon. For more than 2 million years,
human neural net-works kèpt grówing and grówing, but apart from some flint knives & pointed sticks,
humans had precious little to show for it! Whàt then
dróve forward the evolution of the
massive human brain during
those two million
years? Frankly,
we don't
know!

17 sep 2017 - bewerkt op 19 sep 2017 - meld ongepast verhaal
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