1. Evolution – Just A Theory?

2. The Selfish Gene by Richard Dawkins What did you think of the reading? Answer the questions in class… How can we make connections between this reading and our previous units? Why would the idea of sexual reproduction be important for evolution?

3. Whose the man? Charles Darwin Born 1809, 5 th son of wealthy physician Studied medicine and natural history in Edinburgh Studied to be a clergyman at Cambridge

4. Charles Darwin’s Theory Charles Darwin – 19 th century scientist Famous for Theory of Natural Selection –In a population, naturally occurring variations affect which individuals survive and reproduce –Natural selection - the force which acts on populations, and the best adapted organisms survive –Evolution - the process by which populations change over time

5. What is all this controversy? 150 years of controversy

6. Competing Beliefs Many people, even today, do not believe in the theory of evolution, but instead, the idea of creationism. Creationism is static and unchanging… but has meaning and purpose.

7. Intelligent Design Defined as "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.” universeliving thingsintelligentcausenatural selection A “creator” was responsible for the design of what exists on earth NOT a scientific theory/proposal due to the “fact” that there is a lack of evidence and should NOT be taught in science classrooms!

8. The Theory of Evolution The term theory in colloquial use is closer to the concept of a “hypothesis” in science (an educated guess or hunch). In science, a theory  hypothesis. A Theory is more comprehensive than a hypothesis. National Academy of Science: “a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.”

9. Evolution in the news 1925: Scopes “Monkey” Trial –science teacher charged with contravening Tennessee’s Butler Act, which forbade the teaching of "any theory that denies the story of the Divine Creation of man as taught in the Bible, and to teach instead that man has descended from a lower order of animals." 1980s: Alabama and Louisiana laws mandating teaching of “creation science” found to be unconstitutional Right now: Challenges to teaching of evolutionary theory versus “Intelligent Design” in Kansas, Michigan, Pennsylvania

10. Evolution in (some) schools… Disclaimer put into biology textbooks in Georgia- this is now found to be unconstitutional!

11. Darwin’s Theory Darwin published his findings from his trip around the southern hemisphere in a book called On the Origin of Species –Darwin visited the Galapagos Islands, a group of very small islands off the coast of Ecuador. –Even though the islands are close together, each island has a unique climate. Darwin proposed that evolution worked by way of natural selection.

12. Voyage of the Beagle 1831: Joined the HMS Beagle on five year voyage to South America –Studied geology, paleontology, plants and animals

13. Animals of the Galapagos Darwin could tell by the shape of the Giant Tortoises’ shells and their neck length which island they were from.

14. Darwin’s Theory 1. Organisms differ, and some of this variation is heritable. –Some cows produce more milk, some apple trees produce larger apples, etc. –People now use artificial selection: nature provides the variation, but humans select for the variations they find useful Ex. Only breed the dogs that lose the least amount of fur.

15. Darwin’s Theory 2. Organisms produce more offspring than can survive, and many that do survive do not reproduce.

16. Does Darwin’s 2nd part still apply to humans? Many countries are prime examples of overpopulation

17. Darwin’s Theory Because more organisms are produced than can survive, they compete for limited resources. –Struggle for existence. –In this struggle, predators that are faster get more prey.

18. Darwin’s Theory 4. Natural selection causes species to change over time. –Survival of the fittest!!! (natural selection) –Adaptation is any inherited characteristic that increases an organism’s chance for survivial. –Those individuals best adapted to their environment will survive and reproduce.

19. Darwin’s Theory 5. Species alive today are descended with modification from ancestral species that lived in the distant past. All living organisms are Related to one another- common descent. Single “tree of life” links all living things (classification)