The long time frame for including studies and the variance in the reported success rate may diminish this.
However, the mating behavior of Tropheus entails considerably higher variance in the reproductive success of males than of females (Yanagisawa and Sato 1990; Yanagisawa and Nishida 1991; Sefc 2008; Steinwender et al. 2012), making strong sexual selection on females unlikely (Kraaijeveld et al. 2007).
Floater reproduction can potentially alter the sex ratio among breeders, the variance in reproductive success and the levels of multiple paternity within a population (Smith and Arcese 1989).
As expected, the effect of the variance in reproductive success led to the largest reduction in Ne. relative to the census size (N), whereas unequal sex ratios had only a marginal effect.
It has been proposed that heterochiasmy is the result of sexual selection, with the sex experiencing the greater variance in reproductive success exhibiting the lower recombination rate [ 83].
However, multiple mating can be positively correlated with Ne if it does not result in an increase in the variance in reproductive success but rather in an increase in the Ne of the limiting sex (Saura et al. 2008).
One direct measurement of sexual selection that is comparable between species is the variance in reproductive success among the sex with lower parental investment in offspring [ 13– 15].
The NeV estimates were relatively sensitive to changes in the variance in reproductive success, especially at lower values compared to the obtained values (Fig. 4A), but very little with respect to the value of the age-specific survival estimates (Fig. 4B).
In particular, a tendency for females to mate with multiple males has the potential to increase the variance in mating success among males, and provides the opportunity for strong pre- and post-copulatory competition among males [ 4].
Namely, we documented large effect of the variance in reproductive success on reducing the Nb /Ni ratio in a wild salmonid population.
