Why do you think it's highly cited? 

One reason for the high citation is the synthetic nature of the article. Being published in a prominent review journal like TREE allows for broad access to interested people. That coupled with the general appeal of our message, that is, designating endangered populations is best done using a combination of ecology and genetics rather than simply relying on genetics, made this article particularly appealing to a broad range of scientists in environmental biology.

  Does it describe a new discovery or new methodology that's useful to others? 

Yes, in particular, we developed a new approach for designating organismal populations for conservation concern. It has direct relevance to conservation biologists, wildlife biologists, politicians, economists, etc. The field of conservation biology, in general, has broad interest, so the presentation of a new methodology that is essential to the evaluation of endangered species under the Endangered Species Act has very broad appeal.

  Could you summarize the significance of your paper in layman's terms? 

A key component to classifying a population as endangered or not has been a characterization of the amount of differentiation of that population from others. Historically, this has been done using a combination of ecological and genetic information. However, recently, such decisions have been dominated by genetic information. Our paper outlined why this was inappropriate and why going back to a combination of ecological and genetic information was a better approach. We then further suggested that a simple dichotomy between differentiated or not was not ideal, but that multiple options would better represent the continuum of possibilities. We therefore presented a new scheme for classification of population differentiation with multiple categories incorporating both ecological and genetic data in a straight forward hypothesis testing framework. This new approach can be easily used by researchers investigating endangered species to explore the extent of ecological and genetic differentiation.