Month: September 2022

FRAGMENT FROM NATURE considers stubborn questions of the ways we measure brain size, as human have often been singled out as somehow special as a result of their unique brains, mostly based on size compared to other primates. This persistent thread of literature defied the fact that even elephants, dolphins and whales have bigger brains than man, and even that human brain size has decreased somewhat over time. But on it went, and still persists. Enjoy some Tomfoolery. View in LinkedIn

ARE WE ANY DIFFERENT? “What makes us human? Is our brain, the only one known to study other brains, special in any way? According to a recent popular account of what makes us unique, “we have brains that are bigger than expected for an ape, we have a neocortex that is three times bigger than predicted for our body size, we have some areas of the neocortex and the cerebellum that are larger than expected, we have more white matter” – and the list goes on.” https://lnkd.in/d2aUKat View in LinkedIn

EXCEPTIONALISM ON A BELL CURVE. “To regard the human brain as unique requires considering it to be an outlier: an exception to the rule, whatever that rule is. This makes little sense, however, in light of evolution.” https://lnkd.in/d2aUKat View in LinkedIn

THE LADDER OF BEING. “Intelligence has evolved many times independently among vertebrates. Primates, elephants and cetaceans are assumed to be more intelligent than ‘lower’ mammals, the great apes and humans more than monkeys, and humans more than the great apes.” https://lnkd.in/drQAATA View in LinkedIn

MORE WET GOO. “The observation that absolute brain size increased over the past 2 million years is one of the few uncontested facts of hominid evolution.” https://lnkd.in/dvK-CtM View in LinkedIn

PROXIES FOR SMARTS. “Brain properties assumed to be relevant for intelligence are the (absolute or relative) size of the brain, cortex, prefrontal cortex and degree of encephalization.” https://lnkd.in/drQAATA View in LinkedIn

MINE IS BIGGER. “Monkeys, for instance, possess brains that are much smaller than those of ungulates, but the higher cognitive and behavioral flexibility of monkeys over ungulates is anecdotally evident to any observer who compares the ingenious and complex abilities of macaques to those of cows or horses, even though the latter have 4–5× larger brains than macaques.” https://lnkd.in/d2aUKat View in LinkedIn

SMALL SNAG. “Different mammalian orders have traditionally been pooled together in studies of brain allometry, as if their brains were built according to the same scaling rules.” https://lnkd.in/d2aUKat View in LinkedIn

THE WEE PROBLEM. “The assumption that brain size relates to number of neurons in the brain in a similar fashion across orders. This assumption, which was justifiable by the lack of direct estimates of the neuronal composition of the brain of different species, is so widespread that it implicitly or explicitly underlies most comparative studies to date.” https://lnkd.in/d2aUKat View in LinkedIn

THE PRIZE. “An often cited argument in favor of the uniqueness of the human brain is its relatively large cerebral cortex, which accounts for 82% of brain mass.” https://lnkd.in/d2aUKat View in LinkedIn