3.29 Species Variation

Key points:
1. Variation can be described as the differences in the phenotype of individuals. How things appear.
2. It is possible to count or measure these differences and show them in a graph form. The appearance is because of their genotype, which can be modified by the environment. Variation is a variation of all these factors.
3. Variation in population = Variation in genotype + Variation in the environment.
4. Blood groups are an example of where the environment has no effect whatsoever on the variation in population.
5. The height of individuals can be affected by both the environment AND the genotype.
6. A third possibility is that the variation in the population is entirely due to environmental variation, so genes have no role in the differences, an example of this would be language.