Humans Interbred with Four Extinct Hominin Species, Research Finds

Re:Humans Interbred with Four Extinct Hominin Species, Resea... by Symmetry on Tuesday July 30, 2019 @09:22AM (#20564563)

Elephants and whales have big brains but they don't have as many neurons as you'd think from their brain volume. For most mammals neuron count scales as roughly the 3/4 power of brain volume. For primates and birds it scales linearly.

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Re:Humans Interbred with Four Extinct Hominin Species, Resea... by Bartweiss on Tuesday July 30, 2019 @12:01PM (#20566166)

An interesting aside: elephants and whales do still have more neurons than us - African elephants have about twice as many.

But fascinatingly, those neurons aren't evenly distributed, and in fact humans have far more neurons in the cerebral cortex than elephants. Their extra neuron count is almost all in the cerebellum. Primates are skewed towards the forebrain, but elephants are far more cerebellum-heavy than e.g. rodents, which implies that a lot of their extra brainpower is being 'spent' on operating their larger bodies.

By forebrain neuron count, humans are beaten only by pilot whales - and all of the other close contenders are also cetaceans. No one quite seems to know why pilot whales have twice the neocortical neurons humans do, but it's still the number that tracks best with observed intelligence.

http://nautil.us/issue/35/boundaries/the-paradox-of-the-elep...

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