Exotic taxa less related to native species are more invasive

doi:10.1073/pnas.0508073103

Exotic taxa less related to native species are more invasive

*Section of Evolution and Ecology, 2320 Storer Hall, University of California, Davis, CA 95616;
^‡Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520; and
^§Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland

Edited by Christopher B. Field, Carnegie Institution of Washington, Stanford, CA, and approved February 10, 2006 (received for review September 15, 2005)

Abstract

Some species introduced into new geographical areas from their native ranges wreak ecological and economic havoc in their new environment. Although many studies have searched for either species or habitat characteristics that predict invasiveness of exotic species, the match between characteristics of the invader and those of members of the existing native community may be essential to understanding invasiveness. Here, we find that one metric, the phylogenetic relatedness of an invader to the native community, provides a predictive tool for invasiveness. Using a phylogenetic supertree of all grass species in California, we show that highly invasive grass species are, on average, significantly less related to native grasses than are introduced but noninvasive grasses. The match between the invader and the existing native community may explain why exotic pest species are not uniformly noxious in all novel habitats. Relatedness of invaders to the native biota may be one useful criterion for prioritizing management efforts of exotic species.

Footnotes

^†To whom correspondence should be addressed at:
Section of Evolution and Ecology, One Shields Avenue, University of California, Davis, CA 95616.
E-mail: systrauss{at}ucdavis.edu
Author contributions: S.Y.S. and C.O.W. designed research; S.Y.S. and C.O.W. performed research; N.S. contributed phylogenies and analytical insight; C.O.W. analyzed data; and S.Y.S. and C.O.W. wrote the paper.
Conflict of interest statement: No conflicts declared.
This paper was submitted directly (Track II) to the PNAS office.
Freely available online through the PNAS open access option.