Sea Stars Divide into 2 Species in an Evolutionary Flash
[LiveScience 2012-07-25] [Photo] The sea stars Cryptasperina
hystera and Cryptasperina pentagona are close relatives that
look identical but reproduce in very different ways. Pentagona
is a broadcast spawner, and hystera broods its young internally.
A new study shows the species separated just a few thousand
years ago. CREDIT: Jon Puritz, University of Hawaii at Manoa Two
sea stars evolved into independent species in extraordinarily
little time, a genetic study indicates. By examining differences
in the genetic codes of two closely related "cushion stars,"
researchers concluded ancestors of the two species stopped
interbreeding as little as 6,000 years ago. This qualifies as
"one of the fastest known marine speciation events," write the
authors, referring to the creation of new species. The sea stars
may look identical, though they live in different areas on the
Australian coast. One, Cryptasperina hystera, lives on a few
beaches and islands at the far