1. Evidence for Evolution

2. The Fossil Record The fossil record provides evidence of the extinction of species, the origin of new species, and changes within groups over time

3. Fig. 22-15 Bristolia insolens Bristolia bristolensis Bristolia harringtoni Bristolia mohavensis Latham Shale dig site, San Bernardino County, California Depth (meters) 0 2 4 6 8 10 12 14 16 18 1 2 3 3 3 1 2 4 4

4. Evolutionary transitions should leave signs in the fossil record Paleontologists have discovered fossils of many transitional species

5. Fig. 22-17 Humerus Radius Ulna Carpals Metacarpals Phalanges HumanWhale Cat Bat Homology is similarity resulting from common ancestry Homologous structures are anatomical similarities that represent variations on a structural theme present in a common ancestor

6. Human embryoChick embryo (LM) Pharyngeal pouches Post-anal tail Comparative embryology reveals anatomical homologies not visible in adult organisms

7. Vestigial structures are left-overs of features that served important functions in the organism’s ancestors Top 10 Vestigial Structures 10. Wings in flightless birds 9. Hind Leg bones in whales 8. Erector Pili and Body Hair 7. Human Coccyx 6. Blind Fish Astyanax mexicanus. 5. Wisdom Teeth in humans 4. Sexual Organs of dandelions 3. Fake sex in virgin whiptail lizards 2. Male Breast tissue and nipples 1. The human appendix?

8. Astyanax mexicanusVirgin Whiptail Lizards – “Parthenogenesis”

9. Biogeography Darwin’s observations of biogeography, the geographic distribution of species, formed an important part of his theory of evolution Islands have many endemic species that are often closely related to species on the nearest mainland or island

10. Biochemistry In modern research scientists can compare the similarities in the DNA between two related species. The more similar the DNA the more related the two species are.