Natural Selection
Terms
Artificial selection
-
Selection by humans for desired traits. Also called domestication or
breeding.
Choice
-
In sexual selection, the competition for attention from the opposite sex.
Contest
-
In sexual selection, fights or aggressive displays between same-sex
individuals of the same species; contests usually determine possession of
territory or mates.
Directional Selection
-
When selection pressures favor one extreme of the trait distribution.
Disruptive Selection
-
When the average form of the trait is selected against while either extreme
is unaffected.
Fitness
-
The probability that an individual will contribute its genes to the next
generation.
Morphs
-
The different physical forms a trait may have. Long necks and short necks
are examples of morphs.
Natural Selection
-
The theory holding that competition exists within species, determining which
species live to have offspring, and pass their traits on to those offspring.
Polymorphic
-
A trait that exists in several different morphs is polymorphic.
Stabilizing Selection
-
When selection pressures favor the average form of the trait.
Sexual Selection
-
The selection of traits based on their role in courtship and mating.
Trait
-
A particular characteristic of an individual plant or animal.
