1. Chapter 16 Section 4 Evidence of Evolution

2. DO NOW • Read the following passage on Earth’s history of life and explain: • “Of this history, we possess the last volume alone…Of this volume , only here and there a short chapter has been preserved; and of each page, only here and there a few lines.”

3. Fossils Provide a Record of Evolution • ________ are preserved or mineralized remains of an organism • They provide a record of past ________________ • ________ fossilized species are different from newer ones • They show _______ between great groups of organisms

4. Scientists agree on three major points • Earth is about __________ years old • Organisms have inhabited the Earth for most of its history • All organisms living today ________ from earlier, simpler life forms

5. Fossil records are not complete • Many species live in environments where fossils do not form • Most form where organisms are ____________buried in fine sediments deposited by water, wind, or volcanoes • Organisms living in ___________,___________, _______________ will probably NOT form fossils • Paleontologists study fossils and can predict their age using radiometric dating

6. Whale evolution

7. Biological Molecules contain a record of evolution • Proteins- Species that evolved from an ancestor in the distant past should have ________ amino acid differences than those who shared a common ancestor more recently (Example: hemoglobin differences to humans: gorilla=1, monkey=8, mouse=27, chicken=45, frog=67) • Nucleic acids- comparing nucleotide sequences also shows how long it has been since two species _______________ • Together proteins and nucleic acids support the fossil record

8. Anatomy suggests common ancestry • __________ ___________ present in an organism but are reduced in size and either have no use or have a less important function than in other related organisms Examples: _______________ __________________________

9. Homologous structures- structures that share __________ ____________ Example: forelimbs of vertebrates are made form the same basic groups of bones

10. Development also suggests common ancestry • Embryo development is __________ in organisms with common ancestry

11. How quickly does evolution occur? • _______________- gradual change over long periods of time leads to species formation • Punctuated equilibrium-periods of __________change in species are separated by periods of little or no change ( caused by major environmental changes)