Increased genetic divergence between two closely related fir species in areas of range overlap.
Because of introgressive hybridization, closely related species can be more similar to each other in areas of range overlap (parapatry or sympatry) than in areas where they are geographically isolated from each other (allopatry). Here, we report the reverse situation based on nuclear genetic divergence between two fir species, Abies chensiensis and Abies fargesii, in China, at sites where they are parapatric relative to where they are allopatric. We examined genetic divergence across 126 amplified fragment length polymorphism (AFLP) markers in a set of 172 individuals sampled from both allopatric and parapatric populations of the two species. Our analyses demonstrated that AFLP divergence was much greater between the species when comparisons were made between parapatric populations than between allopatric populations. We suggest that selection in parapatry may have largely contributed to this increased divergence.
Key Laboratory of Bio-Source and Environmental Conservation, School of Life Science, Sichuan University 6100061, Chengdu, Sichuan, China ; Umeå Plant Science Centre, Department of Ecology and Environmental Science, Umeå University SE-90187, Umeå, Sweden.
Jing
J
Wang
School of Biology, Mitchell Building, University of St Andrews St Andrews, Fife KY16 9TH, UK.
Richard J
RJ
Abbott
Umeå Plant Science Centre, Department of Ecology and Environmental Science, Umeå University SE-90187, Umeå, Sweden.
Pär K
PK
Ingvarsson
Key Laboratory of Bio-Source and Environmental Conservation, School of Life Science, Sichuan University 6100061, Chengdu, Sichuan, China.
Jianquan
J
Liu
Abies chensiensis; Abies fargesii; allopatry; genetic divergence; natural selection; parapatry