The search for unknown biodiversity

Abstract

[Extract] In a world being rapidly transformed by human activities, an alarming possibility is that many species might disappear before we have a chance to study or even scientifically describe them. This possibility goes beyond a simple desire to document biodiversity, because unknown species could have important benefits for humanity. For instance, who might have imagined that an obscure herb endemic to Madagascar, the rosy periwinkle ( Catharanthus roseus), would yield the only known treatment for childhood leukemia?

How prevalent are undescribed species, and where do they occur? Are they largely concentrated in areas that we already consider conservation priorities, or are they often found elsewhere—meaning that we may need to identify additional priority areas? These questions motivated the study by Joppa et al. in PNAS. With considerable pluck in the face of data limitations and important uncertainties, they attempt to estimate the number of undescribed flowering plant species across much of the terrestrial world.