Number of species depends how you count them

Using genetic analysis alone can overestimate count

Hercules beetles

DRAWING LINES  Scientists sometimes have difficulty determining whether organisms, such as these Hercules beetles, are members of different species. Genetic analysis alone may divide populations into species that don’t exist by other biological criteria.

Clockwise from top left: Smithsonian Institution-NMNH-Insect Zoo/Flickr (CC BY-NC 2.0); Didier Descouens/Wikimedia Commons (CC BY-SA 4.0); JohnSka/Wikimedia Commons (CC BY-SA 3.0); Mashku/Flickr (CC BY-NC-SA 2.0)

Genetic methods for counting new species may be a little too good at their jobs, a new study suggests.