NYT Science: "Stupider With Monogamy"

"Forcing male flies into monogamy has a startling effect: After a few dozen generations, the flies become worse at learning."

This discovery, published on Wednesday in the Proceedings of the Royal Society, isn’t a biological excuse for men who have strayed from their significant other. Instead, it’s a tantalizing clue about why intelligence evolved. 

Concluding paragraphs...

The evolution of learning remains a puzzle for scientists. A smart animal can learn how to find more food or how to avoid predators. But if learning were such an unalloyed good, then one might expect all animals to be as smart as we are.

They are not because there is a cost to learning. Dr. Kawecki and his colleagues have found that flies that have been bred to be good learners are more likely to die when competing for scarce food with regular flies. Even when they’re not threatened with starvation, their life span is 15 percent shorter than average.

It’s still not clear why that is so. Changes to the nervous system that come with learning may cause long-term damage of some sort, or learning may simply use up energy that could be directed to other uses.

Because of the cost, evolution may increase learning only when its benefits outweigh its drawbacks — such as when it affects mating. Dr. Hollis and Dr. Kawecki suspect that fast-learning males may be able to swiftly recognize receptive females, and thus mate with more of them before they die. Forcing the flies into monogamy, on the other hand, gets rid of learning’s benefits, leaving only the cost behind.

To test this idea, Dr. Hollis and Dr. Kawecki compared the mating prowess of the evolved flies. They put a group of male flies in a vial with one receptive female and five unreceptive ones and tallied how many mated in an hour. The scientists found that the polygamous males quickly zeroed in on the receptive female. The monogamous males, on the other hand, wasted time courting unreceptive females and being rejected.

“They’re just not figuring it out,” said Dr. Hollis.

While no one has yet carried out an experiment like this on other species, Dr. Hollis suspects that the relationship between sex and the evolution of learning might apply beyond flies — perhaps even to our own species.

“I think it really can inform us quite a lot about what’s going on in nature, and why we have the brains we have,” said Dr. Hollis.

NY Times 

Note to Self

Self, when making krumkake do not touch the base of the krumkake iron with your bare fingers.

What I was making:

Recipe:

3 eggs, beaten
1/2 cup sugar
1/2 cup butter
1 tsp vanilla, or almond, or lemon, or cardamom
1/2 cup flour

Do the usual stuff with the butter and sugar, flour and eggs, and flavoring.
Cook a teaspoon at a time on a krumkake iron over low-ish heat until they are golden.  Roll onto a tapered dowel while hot.  Slide off the dowel.  Sprinkle with powdered sugar if you must.