The relatively large size of the mammalian brain evolved due to a capacity for endurance exercise, researchers conclude in a recent study.
In the study published in the journal PLoS ONE this month, anthropologists David A. Raichlen of the University of Arizona and Adam D. Gordon of the University at Albany conclude that the brain size in mammals may have evolved in conjunction with increases in exercise capacity, rather than solely in response to natural selection for higher cognitive abilities.
Mammals have larger brains than non-mammalian animals of the same body size; primates (apes, monkeys, humans, lemurs, and lorises) have larger brains than non-primate mammals of the same body size; and humans have larger brains than non-human primates of the same size. Anthropologists have long attempted to discern the reasons humans and other primates have relatively large brains compared to other animals species. The theories offered include the need for greater cognitive power to process visual information, and an increased capacity to manage complex social interactions in large groups.
Gordon said, “Brains are very energetically expensive to maintain, so most previous research has asked why certain species need big, expensive brains. We’re asking a slightly different question: how do species grow and maintain expensive big brains in the first place?”
Earlier research in experimental settings had shown that endurance exercise boosts brain growth in some mammals. Controlling for associations with body size, the researchers examined the correlation between brain size and a metric known as the maximum metabolic rate (MMR), the measurement of the limit for aerobic exercise frequency and capacity. By collecting brain sizes and MMRs in mammals, they analyzed the relationship between body mass and the correlation of residual brain size to residual MMR. They found a significant correlation between maximum metabolic rate and brain size across a wide range of mammals.
Yay exercise! Yay brains!
Understatement of the last 30 years? How about:
“Too much exercise has not been a big problem in America.”
Ya think?
Another point for exercise (I’ve lost track of the score of the exercise vs. sloth game, but I’m pretty sure activity is winning).
And way more important than mitochondrial DNA and all that jazz, were the exercising mice’s “robust gonads.”
+1 for robust gonads.
Pretty interesting correlation. I’ve always thought, aside from the wetness, the PNW temperature was pretty exercise-conducive. Obviously a lot of other factors involved here, but interesting nonetheless.
Daily chart: America’s laziest states. In general, it seems that people who live in cold states like Alaska are more likely to get their weekly work-out than those in sunny Florida
Another one of many benefits of exercise. Cheers to keeping my memory longer!
It seems as though, in rats and people, exercise and alcohol intake are positively correlated. Bottoms up!
Also, later in the article, it says that exercise protects neurons from the negative effects of “indulging.”
So that post-run beer is A-OK!
