DNA in the Dirt Reveals the Number and Species of Animals in the Area

By Veronique Greenwood | September 26, 2011 3:01 pm


Sequencing the DNA in a scoop of dirt can tell scientists what creatures are living nearby, a new study using soil from safari parks shows, and the amount of DNA present can even tell how many individuals of each species there are, which could allow field biologists to get preliminary surveys of species. But though the team managed to identify nearly all the species they had expected in the parks, from wildebeest to elephants, they are still addressing how to take samples that accurately represent the area’s biodiversity—one would have to avoid elephant latrines or wildebeest sleeping areas, for instance—and there is the additional problem that rare or small creatures, like insects, might easily be missed. That said, it’s still an unusual and interesting way to take a look at an area’s inhabitants without actually tracking them down.

Read more at Scientific American.

Image courtesy of malcyzk / flickr

CATEGORIZED UNDER: Environment, Living World
  • http://www.patshipman.com Pat Shipman

    Did they find any animals they did not expect to find? Would this technique reveal the presence of rare or uncommon animals — or animals expanding their ranges into a new territory? Or would it be helpful in getting a species list of animals in areas that are not protected parks?

  • John Kwok

    Am not surprised to see Pat Shipman commenting here since she’s one of our foremost vertebrate taphonomists. While I am intrigued with this, I have to wonder just how biased such samples might be due to time averaging effects, which the lead author of the paper did acknowledge in the Nature news article (reposted over at the Scientific American website). Needlessly to say that is an issue which paleontologists and paleobiologists have had to deal with especially with regards to describing the relative tempo of evolutionary change as seen from stratigraphic columns. It isn’t clear to me how this methodology would address any potential temporal biases in inferring species diversity and abundance given that DNA molecules from certain species will be longer lived than others.

  • Geack

    I’m struck by the fact that large-scale DNA analysis has apparently become more convenient (and presumably cost-effective) than plain ol’ field work. It’s gonna be an interesting next couple of decades.

  • John Kwok

    @ Geack –

    I wouldn’t discount traditional means of estimating species diversity and population sizes yet. There are the potential – and most likely, probable – issues of underestimating species diversity with regards to relatively rare (or small) taxa like insects and of time-averaging effects as I noted earlier.


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