Preadaptation and Naturalization of Nonnative Species: Darwin's Two Fundamental Insights into Species Invasion

[1 ]Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada;

[2 ]Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada

[3 ]School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA