1. SELECTION
NATURAL

2. Theory of Natural Selection
Explains how a population changes over many generations in response to its environment.

3. 1. OVERPRODUCTION
Many species produce more offspring than will survive to maturity.

4. Overproduction Examples
Up to 10,000 Eggs
Up to 10,000,000 Eggs!

5. Overproduction Examples:
THE QUEEN!
>30,000 Eggs a Day, lives for 10 years= >108,000,000 in their lifetime!

6. 2. Genetic Variation
Individuals within a population are slightly different from one another.
Individuals have unique combinations of traits, such as size, color and ability to find food.
Some traits can increase or decrease an individuals chance for survival.

7. Genetic Variation Examples

8. 3. Struggle to Survive
Resources: In any ecosystem, there is not enough food, water, and other resources available for all organisms to survive
Many organisms are killed by other organisms
Only some individuals in a population are able to survive to adulthood

9. The Peppered Moth: The Struggle to Survive Example
In less than 50 years ( ) the once rare dark form accounted for 98% of all Peppered moths in London.
Why?

10. 4. Successful Reproduction
This is the key to Natural Selection!
Individuals that are well adapted to their environment are more likely to survive and reproduce
These “well adapted” traits are then passed on to the next generation

11. Speciation: Darwin’s Finches
When a portion of a population becomes separated, the two populations can become so different over time they can no longer interbreed.
From one come many: Now 13 species of finch on the Galapagos.