Number of species depends how you count them

Genetic methods for counting new species may be a little too good at their jobs, a new study suggests. Computer programs that rely on genetic data alone split populations of organisms into five to 13 times as many species as actually exist, researchers report online January 30 in Proceedings of the National Academy of Sciences. […]

Horses buck evolutionary ideas

A cautionary tale in evolutionary theory is coming straight from the horse’s mouth. When ancient horses diversified into new species, those bursts of evolution weren’t accompanied by drastic changes to horse teeth, as scientists have long thought. A new evolutionary tree of horses reveals three periods when several new species emerged, scientists report in the […]

Supernova spotted shortly after explosion

Astronomers have caught a star exploding just hours after light from the eruption first reached Earth. Measurements of the blast’s light suggest that the star rapidly belched gas in the run-up to its demise. That would be surprising — most scientists think the first outward sign of a supernova is the explosion itself. “Several years […]

Enzymes aid rice plants’ arsenic defenses

BOSTON — Rooted in place, plants can’t run away from arsenic-tainted soil — but they’re far from helpless. Scientists have identified enzymes that help rice plant roots tame arsenic, converting it into a form that can be pushed back into the soil. That leaves less of the toxic element to spread into the plants’ grains, […]