1. The Theory of Evolution

3. Evolution a gradual change in the genetic material of a population. (Population = all the animals of the same species living within a region)

4. Darwin and the Voyage of the Beagle Charles Darwin- the scientists given credit for the discovery of evolution through natural selection.

5. Darwin’s Observations Patterns of Diversity

6. Darwin’s Observations Living Organisms and Fossils

7. Darwin’s Observations The Galapagos Islands

8. An Ancient, Changing Earth Previous scientists recognized that Earth is many millions of years old, and the processes that changed Earth in the past are the same processes that operate in the present. The Earth has changed and is still changing…

9. Natural Variation Individuals, even of the same species, always contain some differences or variation. Additional variation can be added through genetic mutations.

10. Evolution by Natural Selection Organisms best suited for their surroundings will survive and pass on their genes to the next generations. Overtime, only the best genes will remain.

11. The Evolution of the Peppered Moth In England a species of moth called the Peppered Moth had two available, inheritable wing colors- a light color and a dark color. (Dark colored moths had dark colored babies, and vice versa.) Prior to the industrial revolution, the light color dominated with 99% of the moths displaying this phenotype, because it helped the insect blend in light colored lichens covering the trees. However, after the factories opened, the light phenotype became almost extinct and the darker color began to dominate. Why do you think this happened?

12. Evidence of Evolution Darwin argued that living things have been evolving on Earth for millions of years. Evidence for this process could be found in the fossil record, the geographical distribution of living species, homologous structures of living organisms, and similarities in early development.

13. Evidence of Evolution The Fossil Record

14. Evidence of Evolution Geographic Distribution of Living Species

15. Evidence of Evolution Homologous Body Structures

16. Vestigial Structures

17. Evidence of Evolution Similarities in Early Development

18. Patterns of Evolution macroevolution: large-scale evolutionary changes (ex: Reptiles evolving into birds) Microevolution: small evolutionary changes (ex: the peppered moth) Punctuated Equilibrium: Evolution is not a slow process. It consists of long, stable periods interrupted by rapid and brief periods of change.

19. Divergent Evolution divergent evolution: two related species develop more and more differences – examples: polar bear – white fur for camouflage grizzly bear – brown fur to fit in environment If the populations are isolated, it leads to speciation – the formation of new species.