© 2007 The Authors.
© 2007 British
Blackwell Publishing Ltd
Contemporary evolution of secondary sexual traits
in the wild
E. I. SVENSSON and T. P. GOSDEN
Section for Animal Ecology, Department of Ecology, SE-223 62 Lund, Sweden
1. Sexual selection has been studied intensively, and is often strong in natural popula-
tions. Theoretical models, comparative studies and laboratory selection experiments all
suggest that evolution driven by sexual selection should be rapid and common.
2. However, there are relatively few documented cases of the contemporary evolution
of secondary sexual traits in natural populations. Moreover, the causes are not always
due to sexual selection, but often due to altered natural selection regimes, or an altered