Advantages of sexual reproduction resulting from sibling diversity: Effects of selection intensity, environmental variance, and reduced genetic diversity

Background: In a previous paper, we showed that greater sibling diversity among sexual offspring might help to maintain sexual reproduction in environments that are spatially heterogeneous and temporally fluctuating and in which sib-competition is very intense. Question: Can sexual reproduction be maintained in the face of the two-fold cost of sex under milder selection pressure, environmental variance, and reduced genetic diversity? Methodology: Mathematical and numerical analyses of the sib-competition model with several modifications. Conclusions: The advantages of sexual reproduction are attenuated by milder selection pressure and environmental variance but enhanced by reduced genetic diversity. Sibcompetition plays an important role in maintaining sex when the appropriate conditions are present.