BOB HIRSHON (host):
Monarch marathons. I’m Bob Hirshon and this is Science Update.
Monarch butterflies are known for their epic migrations, traveling thousands of miles between Canada and Mexico each year. But the monarch is also found in Hawaii, New Zealand, and other parts of the world where it doesn’t migrate at all. To find out what sets the migrators apart, scientists compared their genomes. Surprisingly, they found reduced expression of the gene for collagen in the migratory butterflies, which is important for wing muscle development. University of Chicago evolutionary biologist Marcus Kronforst explains.
MARCUS KRONFORST (University of Chicago):
We thought that the migratory butterflies would be big powerful flyers, but it turns out that they are using way less oxygen than the non-migratory butterflies. So this is showing in fact that they are the endurance runners, and the non-migratory populations are the sprinters.
The researchers report their findings in the journal Nature. I’m Bob Hirshon, for AAAS, the science society.