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Abstract
Selfish genetic elements bias their own transmission to the next generation, evenat the expense of the fitness of their carrier. Sex-ratio (SR) meiotic drive occurs when anX-chromosome causes Y-bearing sperm to die during male spermatogenesis, so that it ispassed on to all of the males offspring, which are all daughters. How SR is maintained asa stable polymorphism in the absence of genetic suppressors of drive is unknown. Here,we investigate the potential for the female remating rate to affect SR dynamics in naturalpopulations, using the fly Drosophila neotestacea. In controlled laboratory conditions,females from populations where SR is rare mate more often than females frompopulations where SR is common. Furthermore, only when males mate multiply does theaverage fertility of SR males relative to wild-type males decrease to a level that canprevent SR from spreading. Our results suggest that differences in the female mating rateamong populations may contribute to SR dynamics in the wild, and thus also affect theoutcome of this intragenomic conflict. In line with this, we also present evidence of alocalized population crash due to SR that may have resulted from habitat fragmentationalong with a reduced mating rate.