Polymorphic Butterfly Reveals the Missing Link in Ecological Speciation
Nicola L. Chamberlain,1,*
Ryan I. Hill,1,*
Durrell D. Kapan,2
Lawrence E. Gilbert,3
Marcus R. Kronforst1,
Ecological speciation occurs when ecologically based, divergent
selection causes the evolution of reproductive isolation. There
are many empirical examples of this process; however, there
exists a poorly characterized stage during which the traits
that distinguish species ecologically and reproductively segregate
in a single population. By using a combination of genetic mapping,
mate-choice experiments, field observations, and population
genetics, we studied a butterfly population with a mimetic wing
color polymorphism and found that the butterflies exhibited
partial, color-based, assortative mate preference. These traits
represent the divergent, ecologically based signal and preference
components of sexual isolation that usually distinguish incipient
and sibling species. The association between behavior and recognition
trait in a single population may enhance the probability of
speciation and provides an example of the missing link between
an interbreeding population and isolated species.
2 Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
3 Section of Integrative Biology, University of Texas, Austin, TX 78712, USA.
* These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail: mkronforst{at}cgr.harvard.edu
