Effects of exotic species on evolutionary diversification.
Exotic species invasions create almost ideal conditions for promoting evolutionary diversification: establishment of allopatric populations in new environmental conditions; altered ecological opportunities for native species; and new opportunities for hybridization between previously allopatric taxa. Here, we review recent studies of the evolutionary consequences of species invasions, revealing abundant and widespread examples of exotic species promoting evolutionary diversification via increased genetic differentiation among populations of both exotic and native species and the creation of new hybrid lineages. Our review indicates that, although the well-documented reductions to biodiversity caused by exotic species might outweigh the increases resulting from diversification, a complete understanding of the net effects of exotic species on biodiversity in the long term will require consideration of both.
Vellend
Mark
M
Department of Botany, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. mvellend@interchange.ubc.ca
Harmon
Luke J
LJ
Lockwood
Julie L
JL
Mayfield
Margaret M
MM
Hughes
A Randall
AR
Wares
John P
JP
Sax
Dov F
DF
D044822:Biodiversity; D019143:Evolution, Molecular; D005580:Fossils; D014644:Genetic Variation; D006824:Hybridization, Genetic; D058865:Introduced Species