What’s the difference between chickens and whales? I bet you rattled off a laundry list just now, including size, habitat, feathers, the sounds they make… I could go on and on about how different chickens and whales are, but instead I’m going to talk about their brains.

Not just their brains, but the size of their brains, as scientists discovered a link between life longevity in mammals and their brain size.

CREAF scientists,César González-Lagos and Daniel Sol, in conjunction with McGill University researcher, Simon Reader published new findings in the Journal of Evolutionary Biology that suggest mammals with larger brains have a longer life-expectancy than mammals with smaller brains.

Their research included data from nearly 500 different species of mammals, from marsupials to bats. According to their findings, larger brain sizes, as well as larger body sizes, allow mammals more opportunities to adapt to their environmental conditions, create survival solutions and improve their chances of survival as a species. Because they are more likely to survive longer, they have more chances to breed, increasing their population as a species.

Not only are male members of the species offered more opportunities to breed, females with longer life cycles are afforded the opportunity of longer ovulation cycles as well. Animals who live longer are also more-likely to reach sexual maturity later, giving them more time while developing and maturing to adapt to their environment and learn to survive.

As well as brain size, body size is also taken into consideration, as mammals with larger brains also tend to have larger bodies. They also noted that animals born in captivity were also more-likely to live longer than animals born in the wild because there were less environmental situations requiring harsh adaptation skills for captive species.

In the end, the research seemed to denote that brain size was somewhat of a revolving, evolutionary door. Larger brain size equals longer life, longer life equals more time for brain size to increase on the evolutionary scale.

I guess we should be grateful for our massive brain size, though they’re certainly not as big as whale brains. I’m kind of glad I’m not the size of a whale either. It’d make romping through the grocery store a little difficult.

It did make me wonder though… could this be why human obesity rates are on the rise? It’s our brains trying to tell us bigger bodies equal bigger brains equal longer life? Unfortunately, I don’t think that’s the case.