Do our brains require endurance activity in order to function?

The New York Times “Exercise and the Ever-Smarter Human Brain”

While I think that the finding that brain size and capacity for endurance are linked is interesting and important, I am a bit baffled by this article’s take on the evolutionary process that might have driven this connection. Does exercise make our brains larger and (more importantly) more effective? Maybe, but such a change would be an acquired characteristic, and thus rely on LaMarckian rather than Darwinian evolution. I am fine with this, if we posit that there was coevolution between culture (such as hunting practices requiring endurance) and biology (such as the capacity to convert elevated levels of BDNF into more effective brains). But I still find this explanation kind of unsatisfying, because it presupposes the value of a large brain, or of having endurance, or both. To really provide an evolutionary explanation for this connection, we need to explain why the combination of brain size and endurance increases was adaptive. Any other ‘explanation’ is simply correlative.

The later part of this article is interesting in that it discusses the possible ill effects of our increasingly-sedentary lifestyle. If we are mismatched to our current level of activity, we might be less able to use our contemporary brain capacity because we no longer behave in the manner that our physiology had apparently grown to depend on. Again, a fascinating case of gene-culture coevolution.