AMHERST, Mass. For hundreds of years, naturalists and scientists have identified new species based on an organism's visible differences. But now, new genetic techniques are revealing that different species can show little, to no visible differences.
In a just-published study, evolutionary biologists at the University of Massachusetts Amherst and the American Museum of Natural History (AMNH) combine traditional morphological tests plus genetic techniques to describe new species. Groups of morphologically similar organisms that show very divergent genetics are generally termed "cryptic species."
Lead author of an article describing their work with scale insects in the current issue of the journal ZooKeys is AMNH's Isabelle Vea. Co-authors are Ben Normark of UMass Amherst and Rodger Gwiazdowski, once Normark's doctoral student and now a postdoctoral research fellow at the Biodiversity Institute of Ontario, Guelph.
As Gwiazdowski explains, "A basic question about life is asking how many species there are on earth, and a major difficulty in answering it is defining what a species is. It's a big problem both practically and philosophically. There are no standards for how to define species or describe new ones. We've come up with a practical method, combining a conventional morphological approach with a look at genetic patterns that should develop as species form."
Though the evolutionary biologists don't expect their new combined approach to be applicable to all species, they believe it offers a pathway to future researchers looking to negotiate the territory between traditional identification methods and powerful new genetic techniques.
As a doctoral student, Gwiazdowski trekked across North America from Mexico through Canada collecting an especially large number of armored scale insect specimens. "We set out to ask, broadly, what is a species in this group," he says.
Species discovery efforts ar
|Contact: Janet Lathrop|
University of Massachusetts at Amherst