1. Chp15 Evidence and theory development

2. 5 pieces of evidence 1. Fossils 2. Homologous and Analogous Structures 3. Vestigial Structures 4. Embryology 5. Macromolecules

3. 1. Fossils A TRACE of a long dead organism Footprint, trash, poop, eggshell, nest, tools, amber Usually found in sedimentary rock Mold- an imprint in rock of the shape of an organism Cast- a filled mold; a model of the organism animation

4. 1. Fossils Distribution – Where located

5. 1. Fossils Law of superposition What happened first? Relative Age Versus Absolute Age Fossil Record: The theoretical ‘stack’ of all fossils, in order

6. Biogeography: Organisms that are relatively close (NJ and PA) are more alike than organisms that are far apart. More pouched animals in Austrailia Galapagos Finches

8. 2. Homologous/Analogous Structures ‘Homo’ means … so these are parts in different species of animals that are the same. Figs. 15-7 p289 15-8 p290 Analogous – same function but different structure

9. Homologous Structures

10. Analogous Structures

11. 3. Vestigial Structures Are features that seem to have no useful function Wisdom Teeth, Appendix, tail bone – In Humans Pelvic Bone, Four chambered stomach like a cow – In Whales

12. 4. Embryology When they are first growing MANY organisms start out looking the same, THEN start to develop differences Tell us that they are somehow related

13. 5. Macromolecules Macro- “large” Molecules Proteins, Carbohydrates come from the DNA Which means…………… THE DNA IS SIMILAR Whose DNA is yours MOST similar to? Immediate Biological Family Examples- hemoglobin Human to Gorilla ONE difference Human to Frog67 differences Common Ancestors

16. 5. Macromolecules (Lab p334) This tells us that frogs and humans had a common ancestor longer ago then humans and gorillas. What could cause that one difference? Mutation!

17. How did we come up with this stuff? History of Evolutionary Theory Charles Darwin, DOB 1809, On the Origin of Species by Means of Natural Selection, HMS Beagle – 1831-36 Greeks – life arose in water and more complex followed simpler ones Later Aristotle said life was fixed (ps. he’s wrong) Judeo-Christians agreed Mid 1700s fossils of “strange animals” were found Jean Baptiste de Lamark suggested acquired traits were inherited. Used = got better, Unused = go away. (ps…he’s half wrong) ACQUIRED TRAITS happen in a life time Your kids will have your tattoo

18. Dad wanted him to get into medicine, then he went to become a priest – Met John Henslow – took a cruise. While on the boat he read Principles of Geology by Charles Lyell. “mountains rise cm by cm” The way the rain falls today is the same way it fell 1billion years ago. UNIFORMITARIANISM Learned about Thomas Malthus Human population should be huge but - War, Disease, Famine limits the population

19. So Darwin is on a cruise… Finds sea animal fossils thousands of feet above sea level Finds FINCHES similar to the mainland but 600miles out to sea GALAPAGOS ISLANDS Realizes that kids look like parents After his trip, he thinks about this stuff for a little while…like 20years Alfred Wallace sends him a paper that is the same idea that he has come to and Darwin quickly publishes. The conclusion…?

20. Descent with Modification Organisms that exist today are modified versions of older organisms. The environment chooses the organisms that are best fit to reproduce (natural selection). The better fit the organism the more babies it will produce, the more of those genes are in the gene pool. Traits that help an organism survive better and make more babies are ADAPTATIONS