Friendly invasion: end species discrimination!(Citings) (Brief article)

• Author: Bailey, Ronald

FOR YEARS, ecologists have been fretting that foreign species contaminate unique ecosystems. Their fear makes sense: It's easy to see why bringing a family of hungry lions to a small island filled with herbivores might cause serious difficulties.

But newly introduced species may be able to get along with their native brethren better than previously believed. In August the ecologists Dov Sax of Brown University and Steven Gaines of the University of California at Santa Barbara published a study in the Proceedings of the National Academy of Sciences looking at the effect of invasive species on extinction of native species. They found that, in general, introducing exotic species to oceanic islands increases their overall biodiversity.

What's more, with the exception of birds, there is very little evidence that invasive species are causing native species to go extinct. New Zealand, for example, is home to more...