1. Natural Selection

2. What is Natural Selection?
Classic Peppered Moth Example
Primary mechanism for evolution
“Survival of the fittest”
Individuals that have traits that are better suited to their environment will more likely survive and reproduce.

3. Natural Selection Affects…
Populations – a group of organisms of the same species that live in the same geographic area and successfully interbreed.

4. Factors of Natural Selection
1. All populations have genetic variation.

5. 2. Environment presents challenges to successful reproduction.

6. 3. Individuals tend to have more offspring than the environment can support.

7. 4. Individuals that are better able to cope with the challenges presented by their environment tend to leave more offspring than those individuals less suited to the environment do.

8. Adaptations
A feature that is common in a population because it provides some improved function. They are produced by natural selection
Can include:
Behaviors
Proteins that function at the cellular level
Anatomical features

9. Examples of Adaptations
Creosote bush producing toxins that prevent other plants from growing nearby thus reducing competition
Mimicry of leaves by insects to evade predators

10. Example of Adaptations
Echolocation of bats to capture insects

11. Natural Selection At Work
Non-poisonous King Snakes mimic the poisonous Coral Snake
Orchids “fool” wasps into mating with them to spread help spread their pollen

12. Natural Selection At Work
Birds mating rituals can include a “dance”
The male blue-footed booby, shown to the right, exaggerates his foot movements to attract a mate.

13. Natural Selection At Work
Galapagos Island finches beaks are different shapes

14. Natural Selection at Work
Human activity prompted the changes in the 19th century for the peppered moths