Sea Star Evolution

 

Cryptasterina pentagona Right 250Sea star evolution has long intrigued biologists. To explore speciation between two similar-looking sea stars, Jonathan Puritz (pictured below) of the Institute of Marine Biology at The University of Hawaii coordinated a research team to correlate the genetic and geographic differences between two Coral Sea species.

The team’s report, entitled “Extraordinarily rapid life-history divergence between Cryptasterina sea star species,” was published last week in the Proceedings of the Royal Society. Since these sister species, Cryptasterina pentagona (pictured left), and Cryptasterina hystera, have recently been re-classified as two distinct species, the purpose of the study was to investigate the genetic mechanisms driving the sea star evolution of these sisters – a microcosm of evolution.

In The Origin of Species, Charles Darwin argued that all species evolve incrementally from a common ancestor through a process of “natural selection” –

“On the theory of natural selection, we can clearly understand why she should not, for natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by the short and sure, though slow steps.”

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