Reduced Hybrid Viability

∞ generated and posted on 2016.12.24 ∞

Lowered potential to survive in comparison to parents that serves as a postzygotic barrier to reproduction.

Reduced Hybrid Viability refers to a lower potential to survive for organisms whose parents have incompatible genetics, mostly because these parents mated despite being different species.

Basically the products of interspecific crosses can be less capable of surviving to reproduce, resulting in a fewer progeny produced and therefore lower fitness. For example, such progeny could die soon after fertilization, or prior to hatching, germination, or birth. They also can die later but still prior to sexual maturity or, perhaps especially costly for iteroparous organisms, relatively soon following their reproductive maturity.

Though to some degree a waste of gametes, particularly of eggs, early inviability in certain circumstances can be preferable to later inviability and this is particular so if energy that otherwise would have been spent on these offspring can be diverted to other offspring that are not products of hybridization.

On the other hand, some offspring from hybrid progeny can be preferable to none at all, so once these progeny are no longer detracting from the survival of their siblings then some survival, sufficiently long that some progeny are produced, presumably is preferable to no progeny at all. See, however, what is known as hybrid breakdown.