system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how come when other animals mate with their siblings, no birth defects are typically present, but when humans do, there is a high chance of birth defects?
gpt
Inbreeding is just as much of a problem for animals. So much so that many species have evolved methods of avoiding it, such as males leaving the areas where they were born while their sisters stay closer to home. In endangered species, where populations may be very small, you often see signs of "inbreeding depression" - lowered survival and reproductive ability due to a lack of genetic diversity.

Inbreeding is also a huge concern for zoos, with their small captive populations. Zoos keep pedigrees for lot of species bred in captivity, so they can avoid breeding related individuals with each other.

You can see the consequences in pets if you think of purebred dogs, for example. Many dog breeds are likely to get specific medical issues, such as hip dysplasia in golden retrievers, due to many generations of inbreeding.