Why do the babies of incestuous parents come out weird/ugly looking and/or retarded?
The reason incest is bad in nature is more of a genetics problem than anything else. Let’s say there’s a family that has a lot of carriers of a certain disease. If any of the children marry someone from a different family, the gene has less of a chance of being expressed. If two children from the same family marry, the gene is more likely to come out since both children would have it. Even with lower animals, inbreeding is avoided when possible. This is also why there tend to be more health problems with pure bred dogs as opposed to mutts, for example.
