Obviously, the same problem extends into all other aspects of lodging with companion(s). Just as common is traveler's diarrhea, because it disrupts stools and leads to the inevitable constipation; Cause-and-effect: Most people believe traveler's diarrhea is caused by contaminated food or water.
variation in a characteristic that is a result of genetic inheritance from the parents is called inherited variation children usually look a little like their father and a little like their mother but they will not be identical to either of their parents
Basically, this is simple effect of breeding. Natural selection is the effect natural variation has on survival of a species. Consider the variational model to produce 10 children from one parent set, where the fingers are ranging from very short, to longer and very long.