1. Aim: What are the main ideas of Darwin’s theory of natural selection

2. Charles Darwin

3. Overproduction
Within a population, more offspring are born than can possibly survive.

4. Competition
Offspring compete for space, food, water, and other limited resources.

5. Variations
Differences in traits make certain individuals better adapted to survive.

6. Survival of the Fittest
Organisms with favorable traits survive; organisms with unfavorable traits may die off.

7. Reproduction
Individuals that survive pass on the favorable traits to their offspring.

8. Evolution of Species (Speciation)
Over time, there are so many variations that the population becomes a new species.

9. Example: A Giraffe had many offspring
Offspring competed for limited resources
Offspring had different length necks (variations)
Giraffes with longer necks could reach trees and survive; short necked giraffes starved and died (survival of the fittest)
Long-necked traits were passed on to the offspring.
giraffes fighting