Variation

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Variation
- Variation are the differences within a species.
- Most characteristics (e.g. body weight, height, skin colour) are determined by a mixture of genetic and environmental factors.
- Environmental variation causes a wide range of differences (e.g. diet, exercise, temperature)
- Different genes cause genetic variation. Genetic variation also occurs due to mutations - these cause differences in an organisms characteristics.
  - Some characteristics are determined only by genes (e.g. eye colours, blood group, inherited disorders).
- Continuous variation is when the individuals in a population vary within a range - no distinct categories.
  - A graph of continuous variation is an example of a normal distribution curve (a bell shaped curve).
- Discontinuous variation is where there are two or more distinct categories - each individual falls into only one of these.
Different genes cause genetic variation. Genetic variation also occurs due to mutations - these cause differences in an organisms characteristics.
- Some characteristics are determined only by genes (e.g. eye colours, blood group, inherited disorders).