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.
MALCOLM RITTER AP Science Writer, San Diego Union-Tribune Nation
Wed, 10/01/2014 - 10:04am
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.