18.5 Isolation and speciation

What is natural selection

What is speciation?

Adaptive radiation

• The different phenotypes each combination of alleles produces will be subject to selection pressures that will lead to each population becoming adapted to its local environment. Results in changes to the allele frequencies.

Genetic drift

What are the two types of speciation

• Allopatric speciation and sympatric speciation

Allopatric speciation

Sympatric speciation

Geographical variation

Ecological variation

Temporal variation

Behavioural variation

Mechanical variation:

Gametic variation:

Hybrid sterility variation