1. Darwin Presents His Case 15-3
Evolution
Darwin Presents His Case
15-3

2. Inherited Variation and Artificial Selection
Members of each species differ from each in important ways
Darwin argued that variation mattered and was inherited
Darwin states that humans drive “evolution” through artificial selection
=Nature provides the variation, but humans select the desirable trait (ex: fast horses, cows that produce more milk, large fruit)

3. Natural Selection
When populations change in response to their environment
Including competition for food, shelter, and mates
Also includes climate and vegetation conditions
Do only animals evolve?

4. The Struggle For Existence
Variation in genes exist within the genes of every population
Individuals over-reproduce with differences in organisms that are better suited to survive
Over time, the traits that make that organism successful are passed on to the population
Evidence can be seen in the fossil record

5. Survival of the Fittest
Fitness: the ability to survive and reproduce in their environment
Adaptation: any inherited characteristic that increases chance for survival
Darwin termed this natural selection b/c of it’s similarities to artificial selection

6. Over time, Species Change
B/c of the environmental changes and the struggle to survive, species look different now than they did then!
Descent with Modification

7. Evidence of Evolution Living things have been evolving for years
We all came from common ancestors= common descent
Giving us a tree of life!
Most common ancestor at the bottom

8. Evidence Fossil Record Geographical Distribution of Living Species
Homologous Body Structures
Vestigial Organs
Embryology

9. Your Mission
Use your text to give at least one example for each evidence type