Evolution Notes

1. Evolution Notes Zoology Mrs. McCarthy July 15, 2014

2. I. What is evolution? • Evolution is any change in the genes of a population over time • Examples: 1. Antibiotic resistance in bacteria 2. Loss of legs by snakes and whales

3. II. Different kinds of theories of how the world became as it is today • Big Bang – explosion of a mass of matter to create the universe (solar system ~ 4.6 billion years old) • Creationism – Everything created by a divine being • Spontaneous generation – life “just appears”

5. II. Different kinds of theories of how the world became as it is today • Abiogenic molecular evolution 1. Organic molecules gradually assembled from inorganic elements 2. Haldane’s belief a. “Hot dilute soup” – Earth’s primitive atmosphere had H2O, CO2, ammonia b. Organic molecules formed with energy from UV radiation

6. II. Different kinds of theories of how the world became as it is today 3. Oparin’s belief a. Energy from the sun, lightning, and volcanic heat formed organic molecules

7. II. Different kinds of theories of how the world became as it is today • Evolution – gradualism – SLOW change over time 1. First life was probably a “protocell” a. membrane bound cell that reproduced b. Heterotrophic(photosynthesis came later) c. Prokaryotic – early bacteria 2. Probably happened 4 billion years BP(before the present) 3. Life may have originated more than once!

8. III. History of Evolutionary Theory • Jean Baptiste de Lamarck – French biologist 1. First to notice that fossils were remains of past life 2. Lamarckism, or The Theory of Use and Disuse a. organisms acquire adaptations during their lifetime and pass them on to their offspring

9. III. History of Evolutionary Theory b. examples: 1. Snakes lost legs to move well in dense vegetation 2. Giraffes developed long necks from stretching 3. Any change would be passed on to their offspring 3. This theory was later disproved by genetics

10. If Lamarckism was true, women wouldn’t need to do this:

11. Or this:

12. III. History of Evolutionary Theory • Charles Darwin – English naturalist 1. Life history a. expelled from medical school, not good student b. 22 years old, became naturalist for H.M.S. Beagle c. (almost wasn’t accepted, captain didn’t like the shape of Darwin’s nose)

13. III. History of Evolutionary Theory d. made extensive collections of flora/fauna on his 5 year journey e. spent time in Galapagos Islands – noticed different organisms f. published The Origin of Species

16. III. History of Evolutionary Theory 2. Developed the theory of Natural Selection – survival of the fittest a. ALL organisms show variation b. more offspring are produced than can survive c. struggle for survival (to meet basic needs) d. some have a better chance for survival than others e. survival of the fittest f. new species originate

17. III. History of Evolutionary Theory 3. Darwin believed that genes of parents blend in the offspring a. Gregor Mendel’s studies in genetics proved this incorrect

19. IV. Support for the theory of evolution • Sequence of fossil types 1. Fossils – evidence of past life (bones, teeth, shells, imprints, coprolites) 2. Rocks are formed in layers – older rocks are deeper 3. Fossils in old layers are older and more simple

21. IV. Support for the theory of evolution • Vestigial organs – have no CURRENT function 1. Appendix 2. Wisdom teeth 3. Wings on flightless birds 4. Little toe

22. IV. Support for the theory of evolution • Homologous Structures 1. Same structures, but different functions 2. Shows origin in a common ancestor 3. Vertebrate pentadactyl limb a. human arm b. horse leg c. bird wing d. whale flipper e. bat wing

24. IV. Support for the theory of evolution • Embryological Development 1. Organisms go through similar development 2. Humans had gill slits, tail, fine covering of hair

26. IV. Support for the theory of evolution • Agricultural/Animal Domestication 1. Selective breeding (pets, farm animals, crops) 2. Each generation is not the same

27. IV. Support for the theory of evolution • Competition for Existence 1. More animals produced than could ever survive 2. Compete for food, water, shelter, mates

28. IV. Support for the theory of evolution • Genetics 1. Genetic variation 2. Change in gene frequencies over time

29. IV. Support for the theory of evolution • Wiesmann’s Continuity of Germplasm 1. Sex cells must change for evolution to occur

30. IV. Support for the theory of evolution • DeVrie’s Theory of Mutations 1. Change is caused by mutations

31. V. Example of Natural Selection • Microevolution – change of genes in one population • Peppered moth in England 1. Industrial melanism (change in color) 2. Moths were originally white or peppered gray 3. Industrial revolution caused pollution 4. Soot covered trees, causing them to be darker 5. Birds saw and ate light moths on dark trees 6. Dark “mutations” of the moth could blend in and survive 7. Population shifted to the dark version of the moth

32. Peppered Moth

33. Mimicry as an adaptation

34. Ladybug Adaptations

35. Poisonous Frog Adaptations

36. Crocodile Adaptations

37. Crane Adaptations

38. VI. Speciation – development of new species • Reproductive isolation 1. Groups of same species can not contact each other 2. Adapt to separate environments 3. Develop into different species

39. VI. Speciation B. Allopatric speciation – complete geographic isolation of populations

40. VI. Speciation • Adaptive radiation 1. One common ancestor develops into different species based on competition, location, food supply 2. Example: Darwin’s finches

41. VI. Speciation • Punctuated Equilibrium – Eldredge and Gould 1. Macroevolution – large evolutionary changes 2. New species suddenly emerge 3. Species change little, become extinct 4. Explains the gaps in the fossil record

42. VI. Speciation video clip

43. VI. Speciation • Hardy – Weinberg Equilibrium 1. Mathematical formula to prove genes remain constant under certain conditions a. large populations b. random mating c. no mutations d. no selection (survival of the fittest) e. no migration