1. Evolution History of Life and Natural Selection

2. Formation of the Earth: 4.5 bya

3. Molecules present on early Earth: WaterHydrogenAmmoniaMethane Oxygen not present in free form

4. Prehistoric Gases 1. No CO 2 or O 2 no plants or animals prokaryotes evolve 2. Bacteria create CO 2 CO 2 increases in atmosphere plants evolve 3. Plants use CO 2 CO 2 decreases in the atmosphere

5. Gases cont. 1. Plants create O 2 O 2 increases in atmosphere, animals evolve 2. Animals and plants create a balance between CO 2 and O 2.

6. Origin of Life Miller and Urey –Recreated a possible origin of life –Combined ingredients of early earth –Added electricity –Created amino acids

7. Spontaneous Generation Franceso Redi: disproved theory of spontaneous generation Pasteur: pasteurization, disproved spontaneous generation for bacteria

8. Earth Time Line 1. Life in Water 2. Amino Acids 3. Prokaryotes 4. Eukaryotes (Protists) 5. Plants (in water) photosynthesis! 6. Oxygen 7. Invertebrates (in water)

9. Earth Time Line Cont. 8. Plants (on land) 9. Insects (on land) 10. Amphibians (water and land) 11. Reptiles 12. Mammals 13. Archaeopteryx (reptile-bird fossil) 14. Birds

10. Geologic Eras 1. Precambrian: Prokaryotes are the only life forms. Longest era Longest era 2. Paleozoic: Eukaryotes in water and on land: marine invertebrates, insects, fish; land amphibians, reptiles, plants

11. Eras cont. 3. Mesozoic: Age of dinosaurs. First mammals, flowering plants. 4. Cenozoic: Age of mammals.

12. Types of Geologic Dating Relative –Compare layers of rock - Layers are called strata -Lower layers are older Absolute -Calculate amounts of decayed radioactive elements in a rock -Calculate amounts of decayed radioactive elements in a rock -Half-life = how long it will take for ½ of element to decay -Half-life = how long it will take for ½ of element to decay

13. Relative Dating Puts events in order, without actually giving them an age. –Rock A is older than Rock B, which is older than Rock C

14. Absolute Dating Gives an actual age –Rock A is 3.3 billion years old, Rock B is 2.4 billion years old and Rock C is 1.3 billion years old

15. ProkaryotesSimple DNA (circle) Ribosomes Cell wall No nucleus No organelles First cell type Not capable of being multicellular Only example: bacteria

16. EukaryotesComplexDNARibosomes Plants have cell wall Nucleus Organelles (membrane-bound) Evolved after prokaryotes! Can be multicellular

17. How did prokaryotes develop into eukaryotes and eukaryotes develop into all the types of organisms we have today?

18. Jean-Baptiste Lamarck Use and Disuse — organisms will develop parts they need and lose parts they don’t need Acquired Characteristics — organisms will inherit acquired traits of their parents

19. Acquired Traits example The first giraffe had a much shorter neck. As it reached into the trees, its neck got stretched a bit. The first giraffe’s offspring had a bit longer neck. This continued until we had the long- necked giraffe of today.

21. Lamarck’s Idea didn’t work Never supported experimentally Some scientists worked with mice, trying to see if acquired traits were passed on. They never were.

22. Charles Darwin 1859: Publishes On the Origin of Species by Natural Selection Puts out his Theory of Evolution by Natural Selection

23. Natural Selection vs. Evolution Natural Selection: happens to an individual, determines whether an individual survives and reproduces, occurs quickly Evolution: happens to an entire population, creates adaptations, occurs slowly

24. Evolution This is the Grand Unifying Theory of Biology. –It ties ALL of Biology together.

25. Evolution, simplified There is variation in the genes of every species, due to random mutation In any area, some individuals are better suited to live and reproduce The traits that make an individual better suited are passed to offspring Isolation leads to new species formation

26. Definitions: Species Species Can InterbreedCan Interbreed Produce Fertile offspringProduce Fertile offspring Population Population Individuals of the same species in the same placeIndividuals of the same species in the same place

27. Types of Isolation Geographic Isolation: physical barriers: cities, mountains, rivers, highways Reproductive Isolation: reproductive incompatibility, don’t mate at the same time, no longer find each other attractive

28. Speciation As populations become more isolated, their genes continue to change through mutation and natural selection. Eventually, the offspring of the two isolated species can no longer mate; that’s two new species!

29. Pig C and B can no longer reproduce—two new species of pig!

30. Evidence for Evolution All living things can be linked in a one-way “family tree” All living things can be linked in a one-way “family tree”

31. One-way Family Tree It’s one-way because a trait that appears is only continued “up” the tree—never back down. EX: Feathers have developed only in some later reptiles, then were passed to the birds they evolved into. Nothing else has feathers.

32. Evidence for One-way Tree #1 Fossils—”missing links” have been found that have traits of two different organisms EX: Archaeopteryx— had traits of reptiles and birds

33. Evidence for One-way Tree #2 Homologous structures Evolved from same ancestor. Fingers in humans and whales

34. Evidence for One-way Tree #3 Analogous structures Evidence for One-way Tree #3 Analogous structures Evolved for same function, but in a different way in unrelated organisms. EX: Wings in birds and bats

35. Evidence for One-way Tree #4 Vestigial structures No longer needed, but exist in ancestors EX: Skeletal limbs in snakes; Tail bone in humans

36. Rate of Evolution Rate of reproduction: elephants (slow), bacteria (fast) Rate of reproduction: elephants (slow), bacteria (fast) Degree of isolation: more isolated, faster speciation Degree of isolation: more isolated, faster speciation Environmental Pressures: sudden changes means faster selection Environmental Pressures: sudden changes means faster selection

37. Types of evolution Divergent evolution: one species separates into two separate species.

38. Convergent evolution: two unrelated species develop similar solutions to a similar problem. Creates analogous structures – birds and bats develop wings

39. Adaptive radiation: “radiates” out from a common ancestor EX: Finches

40. Survival adaptations Mimicry: copying physical or behavioral characteristics of a more dangerous organism Poisonous! Not Poisonous!

41. Camouflage: copying the physical color and/or shape of an environmental factor Instinct: a innate behavioral trait that enhances survival Imprinting: behavioral modification that ensures young recognize their parent Survival adaptations

43. Primate Evolution

44. Primates are Mammals that have: Opposable thumbs Large brain Good, stereoscopic vision Ability to brachiate Flexible elbows for hand rotation Grasping feet Three kinds of teeth

45. Early Primates Appeared 60-65 million years ago Prosimian –Small bodies –Lemurs, Tarsiers Anthropoids –Human-like primates –Evolved in Africa

46. Hominid Evolution Hominids developed 5-8 million yrs ago Hominids are bipedal First hominids were in genus Australopithecus –“Lucy” most famous fossil hominid More modern hominids were in genus Homo

47. More recent humans Homo sapiens (developed 400,000 years ago) –Neanderthals Europe arrival (100,000 years ago) –Cro-Magnon Europe arrival (40,000 years ago) Americas arrival (12,000 years ago)