NEW YORK -- Monarch butterflies are famous for migrating from the U.S. and Canada to Mexico for the winter. Now a surprising study suggests the species itself also started out in North America some 2 million years ago.
Researcher Marcus Kronforst of the University of Chicago said monarchs were widely thought to have evolved in South or Central America instead. But DNA from 80 monarchs sampled from the Americas and as far away as Europe and Australia points to a North American origin, maybe in the southern United States or northern Mexico.
Kronforst also said scientists had thought the monarch arose from a non-migrating ancestor. But the new study concludes the ancestor did migrate.
The study was released Wednesday by the journal Nature.
