Small, Big-Brained Animals Dodge Extinction

ananyo writes "Large-brained animals may be less likely to go extinct in a changing world, perhaps because they can use their greater intelligence to adapt their behavior to new conditions, according to an analysis presented to a meeting of conservation biologists this week. Plotting brain size against body size creates a tidy curve. But some species have bigger or smaller brains than the curve would predict for their body size. And a bigger brain-to-body-size ratio usually means a smarter animal. The researchers looked at the sizes of such deviations from the curve and their relationships to the fates of two groups of mammalian species — 'palaeo' and 'modern'. Analysis of each group produced similar results: species that weighed less than 10 kilograms and had big brains for their body size were less likely to have gone extinct or be placed on the International Union for Conservation of Nature red list for endangered species. For species larger than about 10 kilograms, the advantage of having a large brain seems to be swamped by the disadvantage of being big — such as attracting the unwelcome attention of humans."

Re:Except

[Dunbal]

So human populations that are wiped out by disease or natural disaster are not smart enough to survive and if we look hard enough humans who have survived have bigger brains? There are plenty of variables that go into determining whether a species becomes extinct or not. Quite a few of them are exogenous to the species. It doesn't matter how smart a fish you are when your lake dries up. Behaviour does not solve all problems or guarantee survival.

Re:The main reason for going extinct:

[RabidTimmy]

It can be argued that this is often the exact opposite case. Chickens and cows as species are doing phenomenal with no end in the foreseeable future for the sole reason that they are tasty and we've decided to keep them around.

A Modest Porpoisal [colbertnation.com]

Re:Except

[DarkOx]

You have to look at it in aggregate the way the study is. Groups of individuals wiped out in natural disasters are just that individuals. Humans survive those disasters because our big brains have enabled large populations of us to live outside what might be considered our most natural habitat. That geographic diversity has protected us as a species from natural disasters.

Your fish example is kinda the same issue. No individual fish however smart is going to be able to cope with the lake going totally dry. However smarter fish might be able to last longer in a lake with changing ecology and shrinking size, during a severe drought, and therefore survive until the rains come. While other species in the lake might die out.

A fish might migrate to a new lake when they are joined by floods. When they separate again a smarter fish species might be better equipped to adapt to the environment of the new lake, colonizing it successfully where other species might have failed. That might enable it to survive as a species even after the first lake dries up.