Giant Tortoises of the Galápagos Islands

1. Giant Tortoises of the Galápagos Islands Section 15-1 Pinta Tower Marchena Pinta IslandIntermediate shell James Fernandina Santa Cruz Isabela Santa Fe Hood Island Saddle-backed shell Floreana Hood Isabela Island Dome-shaped shell

2. Figure 15–1 Darwin’s Voyage Section 15-1

3. Movement of Earth’s Crust Section 15-2 Sea level Sea level Sedimentary rocks form in horizontal layers. When part of Earth’s crust is compressed, a bend in a rock forms, tilting the rock layers. As the surface erodes due to water, wind, waves, or glaciers, the older rock surface is exposed. New sediment is then deposited above the exposed older rock surface.

4. Figure 15–7 Lamarck’s Theory of Evolution Section 15-2

5. Figure 15–14 Geographic Distributionof Living Species Section 15-3 Beaver Beaver Muskrat Beaver andMuskrat Coypu Capybara Coypu andCapybara NORTH AMERICA Muskrat Capybara SOUTH AMERICA Coypu

6. Figure 15–15 Homologous Body Structures Section 15-3 Turtle Alligator Bird Mammals Typical primitive fish

7. Darwin • H.M.S. Beagle 1831-1836 • Galapagos Islands • Finches (beak shape and food source) • Tortoises • Hutton • Earth is very old. • Geologic change is slow. • Lyell • Scientists must explain past events in terms of processes that they can actually observe.

8. Malthus • Population growth is limited by resources, diseases, etc. • Lamarck (wrong idea) • Use and Disuse • Inheritance of Acquired Traits • Wallace • 1858  Sends Darwin ideas basically the same as Darwin’s. • Drives Darwin to publish On the Origin of Species in 1859.

9. Natural Variation • Differences among individuals. • Artificial Selection • Used in agriculture; Better cows, pigs, corn, etc. • Struggle for Existence • Individuals are competing for resources. • Natural Selection “Survival of the Fittest” • Individuals better suited to their environment survive and reproduce.

10. Fitness • Ability to survive and reproduce in it’s ENVIRONMENT. • Adaptation • Inherited characteristic. ***Natural Selection causes………. “Descent with Modification”.

11. Evidence of Evolution Evidence of Evolution Evidence of Evolution • Fossil Record • Geographic Distribution of Living Species • Homologous Structures • Arm of humans, bats, whales, etc. • Vestigial Organs (structures) • Appendix • Leg bones on boa constrictors. • Manatees with fingernails • Embryological Development • http://www.pbs.org/wgbh/evolution/library/04/2/l_042_02.html • Contrivances • Retina of the Eye • Trachea / Esophagus share pathway  Choking

12. Darwin’s Theory Darwin’s Theory • Individuals vary from one another. • Organisms produce more offspring than can survive. • Competition for resources. • Individual variation provides advantages or disadvantages. • Individuals best suited to environment SURVIVE and REPRODUCE. • Species change over time. • Species alive today have descended with modifications. • All organisms on Earth on united into a single tree of life by COMMON DESCENT.

13. Figure 16–2 Relative Frequencies of Alleles Section 16-1 Sample Population Frequency of Alleles allele for brown fur allele for black fur 48% heterozygous black 16% homozygous black 36% homozygous brown

14. Figure 16–6 Graph of Directional Selection • Directional Selection • Individuals at one end of curve have higher fitness. Section 16-2 Key Directional Selection Low mortality, high fitness High mortality, low fitness Food becomes scarce.

15. Figure 16–7 Graph of Stabilizing Selection • Stabilizing Selection • Individuals near the center of curve have highest fitness. Section 16-2 Stabilizing Selection Key Low mortality, high fitness High mortality, low fitness Selection against both extremes keep curve narrow and in same place. Percentage of Population Birth Weight

16. Figure 16–8 Graph of Disruptive Selection • Disruptive Selection • Individuals at both ENDS of curve have higher fitness. Section 16-2 Disruptive Selection Largest and smallest seeds become more common. Key Population splits into two subgroups specializing in different seeds. Low mortality, high fitness Number of Birdsin Population Number of Birdsin Population High mortality, low fitness Beak Size Beak Size

17. Sample of Original Population Descendants Founding Population A Founding Population B Genetic Drift In small populations, chance occurrences can change the frequency of an allele (trait) in a population. Example: Two animals populate a new island. Are they representative of their species? Founder Effect.

18. Hardy-Weinburg Equilibrium (HW) Frequency of alleles will remain constant, IF five conditions are met. No evolution can occur if all five conditions are met. • Random Mating • Large Population • No movement of individuals into or out of population. • No mutations. • No natural selection. *Obviously, we can’t control all five conditions. We can point to these five conditions and show why evolution IS happening.

19. Speciation • Formation of new species • Requires populations be Reproductively Isolated • Behavioral Isolation • Geographical Isolation • Temporal Isolation

20. Concept Map Section 17-2 Evolution of Life Early Earth was hot; atmosphere contained poisonous gases. Earth cooled and oceans condensed. Simple organic molecules may have formed in the oceans.. Small sequences of RNA may have formed and replicated. First prokaryotes may have formed when RNA or DNA was enclosed in microspheres. Later prokaryotes were photosynthetic and produced oxygen. An oxygenated atmosphere capped by the ozone layer protected Earth. First eukaryotes may have been communities of prokaryotes. Multicellular eukaryotes evolved. Sexual reproduction increased genetic variability, hastening evolution. Go to Section:

21. Figure 17-8 Miller-Urey Experiment Section 17-2 Mixture of gases simulating atmospheres of early Earth Spark simulating lightning storms Cold water cools chamber, causing droplets to form Condensation chamber Water vapor Liquid containing amino acids and other organic compounds Go to Section:

22. Figure 17-12 Endosymbiotic Theory Section 17-2 Chloroplast Plants and plantlike protists Aerobic bacteria Ancient Prokaryotes Photosynthetic bacteria Nuclear envelope evolving Mitochondrion Primitive Photosynthetic Eukaryote Animals, fungi, and non-plantlike protists Primitive Aerobic Eukaryote Ancient Anaerobic Prokaryote Go to Section:

23. Geologic Time Scale with Key Events Section 17-3 (millions of years ago) Era Period Time Key Events Cenozoic Mesozoic Paleozoic Precambrian Time Quaternary Tertiary Cretaceous Jurassic Triassic Permian Carboniferous Devonian Silurian Ordovician Cambrian 1.8–present 65–1.8 145–65 208–145 245–208 290–245 363–290 410–363 440–410 505–440 544–505 650–544 Glaciations; mammals increased; humans Mammals diversified; grasses Aquatic reptiles diversified; flowering plants; mass extinction Dinosaurs diversified; birds Dinosaurs; small mammals; cone-bearing plants Reptiles diversified; seed plants; mass extinction Reptiles; winged insects diversified; coal swamps Fishes diversified; land vertebrates (primitive amphibians) Land plants; land animals (arthropods) Aquatic arthropods; mollusks; vertebrates (jawless fishes) Marine invertebrates diversified; most animal phyla evolved Anaerobic, then photosynthetic prokaryotes; eukaryotes, then multicellular life Go to Section:

24. # of Birds # of Birds Beak Size Beak Size • Directional Selection • Individuals at one end of curve have higher fitness.

25. # of Birds # of Birds Beak Size Beak Size • Stabilizing Selection • Individuals near the center of curve have highest fitness.

26. # of Birds # of Birds Beak Size Beak Size • Disruptive Selection • Individuals at both ENDS of curve have higher fitness.