New research shows that birds have as many neurons as mid-size primates. Evolution apparently has figured out a way of packing neurons more densely. Researchers took brains from 28 different species and dissected them.
Although many in the field expected the bird brain could be densely packed, the extent came as a surprise to the study authors. “My expectation was simply that bird brains should be different from mammals in size and number of neurons,” says neuroscientist Suzana Herculano-Houzel, now at Vanderbilt University, one of the senior authors on the paper. “But we didn’t have any idea that the difference would be so extreme that in a parrot brain you would have as many neurons as in a mid-size primate.”
Particularly of interest here is that the advanced cognition capabilities of the small brains of birds might really be the result of the same mechanisms that is usually associated with larger brain size – the number of neurons. Over three years ago I speculated on changes from the early anatomically modern humans to present day humans. I wonder now if this change can be accounted for by a similar mechanism. In other words we really are smarter than the early Homo sapiens because we have more neurons than they did. What’s more this increases the possibility that human intelligence could still be increasing despite the huge energy requirements that the large brain makes on our species.