1. How Does Evolution Occur?
“Nothing in Biology makes sense except in the light of evolution.”
Theodor Dobzhansky
biologist

2. What were Some Early Explanations for Evolutionary Change?
Jean Baptiste de Lamarck ( )
Desire to change- living things have an inborn urge to become more fit for their environment
Use and Disuse- organisms can alter their shape by using their bodies in new ways
Passing on Acquired Traits- characteristics obtained during a lifetime are passed on to offspring

3. What is the Current Theory of Evolutionary Change?
Charles Darwin
Evolution by Natural Selection

4. Living Things Overproduce
More offspring are created that can survive

5. Offspring Vary in their Traits
No two offspring are exactly alike
due to gametes having different sets of genes
mutations

6. There is a Struggle for Existence
Against each other
Mates
Food
Shelter
Habitat

7. Survival of the Fittest
The best adapted offspring survive and pass their genes (traits) on to their offspring

8. Questions
How did the artificial selection carried out by farmers help Darwin develop his theory of natural selection?
What are the four points of Darwin’s Theory of Natural Selection.
Compare the ideas of Darwin and Lamarck regarding evolution. Were Lamarck’s ideas truly scientific? Why or why not?
What did Darwin mean by “fitness”?