Artificial selection on female preferences rapidly alters choosiness and acceptance of divergent male songs in Drosophila

Most models of speciation by sexual selection assume that reproductive
isolation is driven by divergence in female mating preferences. 
However, we still know little about the evolvability of preference
functions, whether they exhibit constraint, and how their specific
properties evolve.  Thus, I imposed artificial selection on
Drosophila athabasca (WN), utilizing no-choice mating trials on females
accepting divergent Inter-Pulse-Interval (IPI) male courtship songs, a key
target of species recognition.  Response to selection resulted in
increased female acceptance of low and high IPI songs by 30 and 26% in
only 10 generations, respectively.  Females selected to mate in
the presence of high IPI songs akin to its sibling D. mahican (EA)
increased their matings to the same level as with their conspecific IPI
songs.  In contrast, females selected to accept low IPI songs
relaxed choosiness; increasing acceptance of both low and high IPI songs
with no evidence of peak preference shift.  These divergent
responses to selection suggest that choosiness and peak preference can
both evolve.  Finally, selection was mostly driven by dominant
alleles, supporting “Haldane’s sieve” and raising the question of their
maintenance.  Overall, these results imply that sexual selection
systems can be easily destabilized in nature.