XIII.3.2.2 Sexual reproduction can enhance an individual’s inclusive fitness
In order for a certain trait, a certain biological property to be the subject of individual natural selection, it is not necessary that it directly increase the viability or fertility of its carrier.It is sufficient if it increases the probability that close relatives, most frequently progeny and siblings, survive to reproductive age.In this case we speak about ”a trait increasing the inclusive fitness of the individual“ and the type of natural selection that is active in the evolution of this trait is called kin selection.The mechanism of kin selection is similar to individual selection, not group selection.
The elbow room hypothesis, the lottery model andthe model of negative heritability of fitness are amongst the models taking into consideration the positive effect of sexual reproduction on inclusive fitness.