Nature Doesn’t Care Where a Species Is From

Conservationists can be quite conservative. It is right there in the name, after all. They like things the way they used to be, in a better past, real or imagined. Their thinking can be slow to change. One idea that has been very slowly changing in conservation science is the popular notion that “invasive species” are very bad for ecosystems—that they are apt to take over or eat native species into oblivion.

For more than 20 years, conservation scientists have been debating whether this is a useful framework. Researchers in invasion biology—the subfield of conservation biology that studies the effects of non-native species—have long allowed that most introduced species are not problematic, and that some are . More recently, some conservationists have argued that the origin of a species does not reliably predict whether it will cause a problem in a particular ecosystem. After all, plenty of native species cause problems too. (White-tailed deer spring to mind.) I’ve been following this debate since 2005, and I’ve seen how acrimonious it can get. My reporting, ’s Ira Flatow, the author Michael Pollan, and many other writers and scientists on a list of “invasive-species denialists” .