03 Artificial Selection
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Artificial selection is when humans purposefully apply selection pressures to populations to intentionally reproduce individuals with desirable traits. Through selective breeding over multiple generations, artificial selection can change a population so certain traits become fixed. For example, farmers have used artificial selection to develop corn from teosinte and cattle breeds like Guernsey cattle and Chillingham White cows that have specific desirable traits.
03 Artificial Selection
- 1. Artificial Selection ALBIO9700/2006JK
- 2. • Most important selection pressure on organisms • Process when humans purposefully apply selection pressures to populations • The intentional reproduction of individuals in a population that have desirable traits ALBIO9700/2006JK
- 3. • In organisms that reproduce sexually, two adults that possess a desired trait — such as two parent plants that are tall — are bred together. In this example, the mechanisms of heredity dictate that the next generation will consist of more tall plants than previous generations. If artificial selection is continued, all of the population will ultimately be tall. • Also called selective breeding , artificial selection is perhaps best understood as a contrast to natural selection, where the random forces of nature determine which individuals survive and reproduce • In both cases, the outcome is the same: a population changes over time , so that certain traits become more common ALBIO9700/2006JK
- 4. Example of artificial selection ALBIO9700/2006JK
- 5. Teosinte and its modern descendent, corn, a product of artificial selection ALBIO9700/2006JK
- 6. Guernsey cattle Chillingham White ALBIO9700/2006JK
- 7. Guernsey cattle Chillingham White ALBIO9700/2006JK