Summary: Evolution in closely adjacent plant populations X:
long-term persistence of prereproductive isolation
at a mine boundary
J Antonovics
Biology Department, Gilmer Hall, McCormick Road, University of Virginia, Charlottesville, VA 22904, USA
Flowering time differences between metal-tolerant and
nontolerant populations of the grass Anthoxanthum odor-
atum growing across a mine boundary have persisted
for over 40 years. These flowering time differences result
in a high degree of prezygotic genetic isolation (isolation
index ¼ 0.43) between the tolerant mine populations and
nontolerant pasture populations. Previous work showing
genetic determination of flowering time and a high turnover
of individual plants argues strongly for the selective main-
tenance of this difference.
Heredity (2006) 97, 33­37. doi:10.1038/sj.hdy.6800835;
published online 26 April 2006
Keywords: sympatric speciation; parapatric speciation; metal tolerance; cline; Wallace effect; assortative mating
Introduction
The past 50 years have seen a maturation of theories of

Source: Antonovics, Janis - Department of Biology, University of Virginia

Collections: Biology and Medicine