Air Date: Week of October 3, 2003

Living on Earth's Jennifer Chu reports on fruit fly research that suggests it may not always pay to be smart.

Transcript

CURWOOD: Just ahead: charges of cruelty in the slaughter of animals for kosher diets. First, this Note on Emerging Science from Jennifer Chu.

[SCIENCE NOTE THEME]

CHU: It doesn’t always pay to be smart. At least that’s what researchers in Switzerland found out in their experiments with fruit flies. They allowed the bugs to lay eggs on gels flavored with either pineapple or orange juice. But to some of the gels they added a touch of bitter quinine. That way, flies could learn to avoid that particular flavored gel.

Scientists then presented the same flies with juice gels that contained no quinine. Some of them remembered which flavored gel had originally contained quinine, and avoided that flavor. Researchers then separated out those fast learners and bred them. It turns out the descendants of these so-called smart flies learned the same avoidance task in one try. Ordinary fruit flies needed at least three attempts.

But when researchers pitted the smart flies against ordinary ones in a competition for food, the ordinary insects won out. Why? Well, researchers think the smart flies spent more energy developing their brains and so had less energy to develop basic survival skills, like foraging for food. The authors say future research may determine whether primates, including humans, made the same evolutionary tradeoff for intelligence.

And that’s this week’s Note on Emerging Science, I’m Jennifer Chu.

CURWOOD: And you're listening to Living on Earth.

CURWOOD: Welcome back to Living on Earth. I’m Steve Curwood.

[MUSIC: Parlour “The Living Beginning” OCTOPUS OFF-BROADWAY ( Temporary Resistance, Ltd. - 2002)]