Why is inbreeding rarely a problem among animals in the wild?

Answer 1

Inbreeding is the breeding of close relatives--say, brother-sister, father-daughter, mother-son, etc. Linebreeding is the breeding of more distant relatives.

In some cases, used sparingly, it is used by breeders to cement traits in their lines--both parents will have very similar genetics, and thus very consistent type in the offspring is likely. It carries high risks, however, for the same reason--not only are you increasingly the likelihood of desirable recessives appearing in the offspring, but also of undesirable or even dangerous traits appearing.

Used by breeders who understand the risks, it -can- be used responsibly to improve a gene pool. Generally, however, it is discouraged among animal breeders and linebreeding can be used to cement traits in a somewhat safer manner.

Many species, if provided unrelated options for mates, will not mate as willingly with close relatives in natural situations--in the absence of other mates, however, most will mate with relatives which can lead to severe problems in species with very low populations (whether endangered species or species in a small area with no opportunity to mate with outside population, as with the wolves of Isle Royale).

Answer 2

In the wild, inbreeding can persist for decades without population extinction. Some species adapt to circumstances better than others.