Scubaism

American and Canadian scientists have found evidence that fishes living in coral-reef habitats undergo higher rates of diversification than similar groups living in other habitats. The biologists examined the DNA of 67 species of tetraodontiform fishes (pufferfishes and their allies) and compared them with a series of fossils.

The authors found that tetraodontiform lineages associated wih reef habitats generally experience greater rates of diversification than nonreef-associated lineages.

In addition, the authors found that the pattern of diversification is complex and does not suggest an ancient reef-fish association, but coincides with reef diversifiacation and marine provincialization during the late Oligocene (about 25 million years ago).

The authors argue that this increase in diversification rate is due in part to the ecological opportunities provided by the unique and complex reef habitat, and in part by major paleoclimatic events that have increased diversification rates in reef clades by fragmenting reef biotas.