BIOL 202 Study Guide - Midterm Guide: Birth Weight, Disruptive Selection, Directional Selection
Document Summary
Individuals with the average form of trait have the highest fitness: reduces the amount of variation in a trait, mean value stays in the middle, examples, a classic example is that of the birth weight of human babies. If the birth weight is too low, the baby will be very weak and will experience considerable health problems. On the other hand, if it is too high, it will have trouble in passing through the birth canal, thereby inducing complications that could threaten the well-being of both the child as well as the mother. An average birth weight is the only scenario where the baby is born healthy without any problems, hence it is favored. Increases the amount of variation in a trait. Individuals with either of the extreme variation of a trait have greater fitness than individuals with the average form of the trait: examples, chinook salmon males compete with each other to fertilize the female egg.
