Extraordinary Flux in Sex Ratio
Sylvain Charlat,1,2*
Emily A. Hornett,1
James H. Fullard,3
Neil Davies,2
George K. Roderick,4
Nina Wedell,5
Gregory D. D. Hurst1
The ratio of males to females in a species is often considered
to be relatively constant, at least over ecological time. Hamilton
noted that the spread of "selfish" sex ratio-distorting elements
could be rapid and produce a switch to highly biased population
sex ratios. Selection against a highly skewed sex ratio should
promote the spread of mutations that suppress the sex ratio
distortion. We show that in the butterfly Hypolimnas bolina
the suppression of sex biases occurs extremely fast, with a
switch from a 100:1 population sex ratio to 1:1 occurring in
fewer than 10 generations.
2 Gump South Pacific Research Station, University of California, Berkeley, BP 244 Maharepa, 98728 Moorea, French Polynesia.
3 Department of Biology, University of Toronto at Mississauga, 3359 Mississauga Road N, Mississauga, ON L5L 1C6, Canada.
4 Environmental Science (ESPM), University of California, Berkeley, CA 94720–3114, USA.
5 School of Biosciences, University of Exeter, Cornwall Campus, Tremough, Penryn TR10 9EZ, UK.
* To whom correspondence should be addressed. E-mail: s.charlat{at}ucl.ac.uk
