(Crossposted from NeuroDojo)
Now you may be thinking that lemurs are all just the same. You know, cute and cuddly adorableness. But let me tell you, you would be mistaken.
Look at Maurice here. Very efficient, smart enough to be recognizing true greatness in his kingly king when he sees such magnificence presented in front of his eyeballs.
But now we have Mort. Mort is, shall we say, easily swayed by shiny objects. I blame the extreme difference in the seasons where... Mort? Mort! Do not be touching the feet of the king!
As I was saying, there are many reasons to have a small brain. For one, it can be very efficient to have a small brain. Trust me. This big brain of mine? Exhausting. It is no wonder I have to be eating so much to keep up my smarty-pants.
It is also to your advantage to have a small brain when one glorious day is much like the next glorious day. I mean really, you don’t need to be exercising your gray matter much if the problems you solved yesterday are the same problems your going to solve tomorrow. Especially if you can just send Maurice to look after them.
And I know this because van Worden and crew measured the brains of many lemurs. Okay, there were lorises too, but really, how interesting are those? Bug eaters. Do you really want to be known for saying to your friend, “Oh look, you have a grub stuck in your teeth”? No. No you do not. They had this idea to test whether the changing seasons would make lemurs (and stupid lorises) have small brains, because it was expensive to keep them going in the down seasons when there’s little food, or have big brains, because the lemurs (and stupid lorises) need to have the smarty-pants to figure out what to do when the weather changes.
After they do all their fancy crunching of the numbers, they tell me that the places with the biggest changes in seasons are the places where the lemurs (and stupid lorises) have the smallest brains. And I said, “Well, that explains it. Mort is from Bekopaka, and you know what they say about Bekopaka? If you don’t like the weather, wait five minutes!”
This royal joke was lost upon them.
So the finding is that if you want to have a big brain like myself, you need a constant supply of food, not one that goes and comes like the weather fairy friend. Maurice! I’ll be taking that refill on my plate now.
van Woerden J, van Schaik C, & Isler K. 2010. Effects of seasonality on brain size evolution: evidence from strepsirrhine primates. The American Naturalist 176(6): 758-767. DOI: 10.1086/657045