17 2.6 Natural versus artificial selection
1Who selects
Natural selection
- The environment
Artificial selection
- Humans
2Purpose
Natural selection
- Survival and adaptation
Artificial selection
- Human needs and benefit
3Rate of change
Natural selection
- Usually slow, over long periods
Artificial selection
- Can be relatively fast
4Traits selected
Natural selection
- Those that help survival in that environment
Artificial selection
- Traits desired by humans (yield, milk, size)
5Examples
Natural selection
- Dark moths after pollution; thick fur in cold regions
Artificial selection
- Selecting high-milk cows; larger fruits
Stability and change. Organisms keep some inherited traits for long periods, while others change with the environment or because of selection.