1. Evolution Chapter 15

2. Definition a theory that the various kinds of plants and animals are descended from other kinds that lived in earlier times and that the differences are due to inherited changes that took place over many generations

3. Charles Darwin Known as the Father of Evolution Wrote book On the Origin of Species Believed that all species came from a common ancestor.

4. Evidence for Evolution The fossil record – show biodiversity, mass extinctions and episodic speciation Geographic Distribution of Living Species – shows similarities among species living on different continents Homologous Body Structures – structures that have different mature forms but come from the same embryonic tissue. Similarities in Early Development – embryos of many vertebrates are very similar.

5. Natural Selection Over time, natural selection results in changes in inherited characteristics of a population. These changes increase a species fitness in its environment

6. Evidence of Evolution The Fossil Record Geographic Distribution of Living Things-similar environments have similar types of organisms Homologous Body Structures Similarities in Early Development

8. Homologous structure

9. Evidence for Evolution Vestigial organs-organs that serve no useful function in an organism i.e.) appendix, miniature legs, arms

10. Example of vestigial structure; Human and snake

11. Summary of Darwin’s Theory Because more organisms are produce than can survive, each species must struggle for resources Each organism is unique, each has advantages and disadvantages in the struggle for existence

12. Summary (cont.) Individuals best suited for the environment survive and reproduce most successful Species change over time