Genetic Variation

Two types:

1. Discontinuous: usually coded for by one gene - specific outcome, e.g. hair colour

2. Continuous: usually polygenic - many outcomes, e.g. mass, height

Caused by:

- Variation during meiosis

- Mutations

- Environmental factors


Gene frequencies are predicted by the Hardy-Weinberg

Total frequency for phenotype, p and q: p + q = 1

p2 + 2pq + q2 = 1, whereby:

p2 = frequency pf AA

2pq = frequency of Aa

q2 = frequency of aa


Assuming: large population, random breeding, no natural selection, no allele mutations