1. Evolution Notes

2. Indirect Evidence  Data gathered by looking at the effects of an event rather than witnessing the actual event.

3. Evolution  is a change in the inherited traits of a population from one generation to the next. This process causes organisms to change over time.inheritedtraits populationgeneration

4. Conditions required for fossils to form  Sediments like sand or silt  Quick burial of organism  Bones or shells

5. Do all dead organisms make fossils?  No!!  Most organisms are eaten, decomposed, broken apart, etc instead of becoming fossils.

6. Types of fossils  Amber = hardened tree sap  Bones and petrification  Molds, casts, and imprints

7. Ice

8. Bones and petrification

10. Molds, casts

11. Imprints and trace fossils

12. Relative dating  Relative dating

13. Radioactive Dating  The radiocarbon dating method was developed in the 1940's by Willard F. Libby and a team of scientists at the University of Chicago. It subsequently evolved into the most powerful method of dating late Pleistocene and Holocene artifacts and geologic events up to about 50,000 years in age.

14. Index Fossils  Common, widespread, fossils that only existed for a “short” time.  Useful for estimating a time period for rock strata that contains these fossils.

15. Transitional forms/ missing links  An organism that shows the transition from one species to another.

16. Comparative cytology

17. Comparative biochemistry  DNA  Amino Acid sequences  Enzymes

18. Comparative anatomy  Homologous structures

19. Comparative anatomy  Analogous Structures

20. Comparative anatomy  Vestigial structures

22. Comparative embryology

23. Origins of Life  Spontaneous generation –Some used to think that flies came from rotting meat and mice came from hay

24. Origins of life  space seed hypothesis –Bacteria from a meteor from another planet  In 1969 a meteorite (left-over bits from the origin of the solar system) landed near Allende, Mexico. The Allende Meteorite (and others of its sort) have been analyzed and found to contain amino acids  special creation theory –A creator (god) made the first cells  Heterotroph Hypothesis –The first living things ate chemicals from the “primordial soup”

25. Early earth conditions  The atmosphere was methane, ammonia, water, and hydrogen gas. X-rays and UV rays from the sun were not blocked by the atmosphere.

26. Present Earth Conditions UV Rays are blocked by the ozone layer X-rays are absorbed by Nitrogen and Oxygen in the atmosphere Atmosphere is made of Nitrogen, Oxygen, a little carbon dioxide, and some water vapor. Our oxygen comes from autotrophs!

27. Stanley Miller Experiment

29. Amino Acids were formed

30. Hydrothermal vent where chemotrophs live

31. Lamark: Law of use and disuse

32. Lamark  Inheritance of acquired traits

33. August Weismann:  Disproved acquired inheritance.

34. Darwin  English naturalist  Took a 5 year trip around the world  Was one of the people who developed the idea of evolution.

35.  Overproduction –Most species produce far more offspring than are needed to maintain current population levels  Competition –Food, space and other resources are limited. Not all organisms will get their needs met.  Variation –There are differences between members of a species.  Adaptations –Some variations increase an organisms chance of survival.  Natural Selection –The environment “selects” organisms with advantageous traits, they survive, reproduce, and pass on the good traits to their offspring.

36. What is a species?  Organisms that are able to reproduce and make viable offspring are of the same species.  Speciation = formation of a new species.

37. Modern Theory of Evolution  How do natural variations occur? –Mutations  A change in the DNA –Sexual reproduction (crossing over)

38. Natural Selection  This is the mechanism of evolution.  Traits that help you survive will be passed on to your offspring. The frequency of that useful trait will increase in the population = change

39. Examples of natural selection  Mosquitos that are resistant to DDT

40. Examples of natural selection  Penicillin resistant bacteria

41. Examples  Peppered moths

42. Camouflage

44. Warning Coloration

45. Mimicry

46. Types of natural selection  Directional

47. Types of natural selection  Stabilizing

48. Types of natural selection  Disruptive

49. Speciation  Range  Where an organism lives

50. Speciation  Geographic isolation: species adapt to new environments

51. Bottleneck effect

52. Speciation  Reproductive isolation –Genetic, behavioral, timing differences

54. Speciation  Polyploidy –More than the normal # of chromos omes

55. Speciation  Adaptive radiation –One species evolves into many different species.

56. Convergent evolution  Natural selection that causes unrelated species to resemble each other.

58. Co-evolution: two or more species that evolve in response to each other

60. Gradualism

61.  Gradualism: slow and gradual changes regularly over time.  Punctuated Equilibrium: quick and sudden changes followed by a long period of stability.

62. Population  A group of species in an area.  Evolution is a change in the frequency of a gene in a population of organisms over time.

63. Gene Pool  A gene pool is the sum of all the individual genes in a given population

64. Extinction

65. Microevolution vs. Macroevolution