Speciation
Factors which prevent individuals from mating. Geographic isolation: Species occur in different areas, and are often separated by barriers.Temporal isolation: Individuals do not mate because they are active at different times. This may be different times of the day or different seasons. The species mating periods may not match up. Individuals do not encounter one another during either their mating periods, or at all. Ecological isolation: Individuals only mate in their preferred habitat. They do not encounter individuals of other species with different ecological preferences.Behavioral isolation: Individuals of different species may meet, but one does not recognize any sexual cues that may be given. An individual chooses a member of its own species in most cases. Mechanical isolation: Copulation may be attempted but transfer of sperm does not take place. The individuals may be incompatible due to size or morphology.Gametic incompatibility: Sperm transfer takes place, but the egg is not fertilized.