Isolation and speciation

Geographical:

• populations are isolated by physical barriers such as oceans etc

Ecological:

• populations inhabit different habitats within the same area and so individuals rarely meet

Temporal:

• the breeding seasons of each population do not coincide and so they do not interbreed

Behavioural:

• mating is often preceded by courtship, which is stimulated by the colour or markings of the opposite sex, the call or particular actions of mate

Mechanical:

• anatomical differences may prevent mating occuring, for example, it may be physically impossible for some males to mate with females

Gametic:

• the gametes may be prevented from meeting due to genetic or biochemical imcompatibility.
• for instance, some sperm are destroyed by chemicals in the female reproductive tract

Hybrid sterility:

• hybrids formed from the fusion of gametes from different species are often sterile because they cannot produce viable gametes

Speciation:

• the evolution of new species…