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
Heritability: The variation found in the population must (at least partially) be heritable, e.g. transmitted from parent to offspring. If the variation in the trait was due entirely to the environment, for example, changes in the parent population would not affect the characteristics of the offspring population. 3. Differential Mortality: Finally, individuals must have a probability of survival that is a function of the value of the trait in question.