A team from UC Santa Barbara is working on this very question, and they've just published a study in the Proceedings of the National Academy of Sciences. They believe Earth is in its sixth mass extinction, which will kill off nearly 50% of all plant and animal species. Figuring out which endangered plants to save may be the key to minimizing the ecological impact of this particular extinction:

"Losing a very unique species may be worse than losing one with a close relative in the community," said [co-author Todd] Oakley. "The more evolutionary history that is represented in a plant community, the more productive it is."

[Post-doctoral fellow Marc W.] Cadotte explained that the buttercup is a very unique species, evolutionarily. Losing the buttercup, where it occurs in grasslands, would have a much bigger impact on the system than losing a daisy or a sunflower, for example. The latter species are closely related. Each could therefore help fill the niche of the other, if one were to be lost. The daisy and sunflower also have a more similar genetic make-up.

It may be a sad day for the daisy, but ensuring the survival of a genetically diverse array of plant life will help ensure a sufficient level of biomass, and could reduce the devastation a mass extinction would cause.

Image by Martin Heigan.

Current Mass Extinction Spurs Major Study of Which Plants to Save [via Science Blog]

The Barcelona-based international conservation agency publishes its Sampled Red List Index to give a quick representation of trends in the natural selection market (graphic from New Scientist). Only 2.5 percent of all known plants and animals have been documented, and while that number might be a bit misleading, the process for seeing exactly which species were in danger was a cumbersome one. IUCN uses random samplings of 1500 species to assess larger risk. While cruder, such estimates can give a quick idea of the threat level before it's too late.

As you can see, the danger is most pressing in the mammalian sector. Although humpback whales are swimming back from extinction, many precious mammalian species are at risk. Marine mammals are the usual target, specifically those in northern oceans, according to an article that appeared in Science.

Viewing animals like shares reveals vanishing species [New Scientist]