Ecologists usually work by catching and tagging as many animals as they can in order to determine biodiversity, but an easier method may be "just beneath their feet," says Nature News' Amy Maxmen. A new study published in Molecular Ecology shows that soil containing fragments of DNA may work just as well to accurately capture the animal diversity of an area, Maxmen says. The new technique requires far less time and energy than the old method, and doesn't risk causing the animals harm. Using the DNA left behind in skin cells, scales, or waste, the researchers can determine not only which species of animals were once present in an area, but also how many of each species were there. To prove that the method works, the team took DNA samples from farms and safari parks, extracted the DNA from the soil and sequenced the fragments. "When they compared individual sequences to the millions of sequences stored in the DNA database GenBank, they found all the animals they expected," Maxmen says. "The quantity of a species' DNA recovered roughly reflected the number of animals of that species present, after adjusting for body weight." And, she adds, the technique could be used to identify not only the animals currently living in the area, but the animals that were living there, as much as two months before. Digging deeper into the dirt could uncover the biodiversity of an area going back thousands of years, the researchers add.
Here Be Wildebeests
Sep 27, 2011