AUSTIN, Texas — Breaking up may actually not be hard to do, say scientists who've found a population of tropical butterflies that may be on its way to a split into two distinct species.

Heliconius species Polymorphic mimicry in Heliconius cydno alithea in western Ecuador, where the white form (middle left) mimics the white species Heliconius sapho (top left) and the yellow form (middle right) mimics the yellow species Heliconius eleuchia (bottom right). Image: Marcus Kronforst and Krushnamegh Kunte

The cause of this particular break-up? A shift in wing color and mate preference.

In a research paper published this week in the journal Science, the researchers describe the relationship between diverging color patterns in Heliconius butterflies and the long-term divergence of populations into new and distinct species.

Source: http://www.utexas.edu/news/2009/11/05/butterflies_species/