23 May 2011
Biodiversity - species loss revisited
Carsten Rahbek and Rob Colwell writes in Nature about study demonstrating that Species-Area-Curves often overpredicts rate of species extinctions.
Conservationists predict massive extinctions as a result of habitat loss. Habitat loss undoubtedly does drive extinctions, but dealing with an unmet assumption that underlies these predictions yields much lower estimates.
Scientists generally agree that Earth is facing a biodiversity crisis, losing species 100 to 1,000 times faster than the normal background rate of extinction and resulting in the sixth period of mass extinction in Earth's history. However, He and Hubbell provide in a Nature-article (Nature vol 473: 368-371) a fresh perspective on predictions of the rate of this species loss. They demonstrate that a widely used indirect method of estimating extinction rates - based on backward extrapolation of species-area relationship data - tends to overestimate the problem. In a News & Views article in Nature (vol 473: 368-371), Carsten Rahbek and Robert Colwell outline their findings and put it into a broader perspective. Download News&Views article here.