2. Charles Darwin

3. In 1831, at the age of 21, he set sail on a five-year voyage on the HMS Beagle, collecting and mapping South America & the South Pacific.

4. He studied and compared the anatomy of many species of reptiles, insects, birds, and flowering plants he observed on his trip. He observed that many species are unique yet similar to species seen in other parts of the world.

5. By the end of his trip, Darwin was convinced that evolution occurs – that species change over time. Using data he gathered from the natural world, Darwin began to form his well-known idea of evolution by natural selection.

6. In 1859, Darwin published a controversial book - On the Origin of Species by Natural Selection. Controversy led to criticism of Darwin’s ideas.

7. Natural selection is a mechanism for change in populations. Diversity within a species allows natural selection of favorable traits to occur.

8. Organisms with favorable traits survive, reproduce, and pass these variations on to the next generation.

9. Organisms with less favorable variations are less likely to survive and pass on traits to the next generation.

10. The idea of natural selection is often referred to as “SURVIVAL OF THE FITTEST”.

11. An adaptation is any trait that aids the chances of survival and reproduction of an organism.

13. Darwin’s theory of natural selection can be applied to explain the evolution of adaptations in organisms.

14. The thorns of rosebushes and the spines of sea urchins are used for defense against predators

16. Mimicry provides protection for a an organism by enabling it to copy the appearance of another species. Structural Adaptations

17. defensive adaptation that involves changes to the color of organisms It enables an organism to blend in with its surroundings. Organisms that are well camouflaged are more likely to escape predators and survive to reproduce. Structural Adaptations

18. Structural Adaptations: Camouflage

19. changes in an organism’s metabolic processes Only 50 years ago, the antibiotic drug penicillin was considered a wonder drug because it could kill many types of disease- causing bacteria. Today, scientists know that penicillin is not as effective as it used to be because many species of bacteria have evolved physiological adaptations that make them resistant to penicillin. Rapid changes have also been seen in pest organisms. Bacteria has evolved & become more resistant to drugs.

20. Most of the evidence for evolution comes from indirect sources.

21. Are an indirect source of evolutionary history of animals such as whales provide a record of earlier life. fossil record is incomplete it shows that 40 to 50 million years ago, horses were a species of small, dog-sized animals

24. Structures with common evolutionary origin Can be similar in arrangement (structure), function, or both

25. Do not have a common evolutionary history. Any body part that is similar in function but different in structure Bird wings are made of a set of bones, whereas insect wings are mainly composed of a tough substance called chitin.

26. Structure in a present-day organism that no longer serves its original purpose, but was probably useful to its ancestor

27. May develop as species change in form and behavior. May serve no function, but continue to be inherited as part of the body plan for that species. The wings of an ostrich are Vestigial since they are Flightless.

29. Human appendix useless yet in other mammals, including primates, it is necessary to aid in digestion of high cellulose diet Human external ear muscles still present but useless Humans have tailbones and some babies occasionally have tails.tails

30. Human wisdom teeth are vestigial compared to other primates Some snakes have skeletal limbs. Cave dwelling crayfish have eyestalks yet no eyes.

31. Sometimes vestigial organs may be adapted for new uses, e.g. penguin wings can't be used for flight yet adapted for swimming.

33. Embryo – the earliest stage of growth and development of a plant or an animal Similarities among vertebrate embryos suggest evolution from a common ancestor. In the earliest stage of development, a tail and gill slits can be seen in all species. As development continues, the embryos become more and more distinct.

35. Fish embryo Chicken embryo Pig embryoHuman embryo

36. The most recent evidence for evolution has come from comparisons of DNA & RNA within taxonomic groups. One study of comparisons of RNA sequences led to the construction of an evolutionary tree that shows 3 major groups: the eubacteria, the archaebacteria, and eukaryotes.

37. If an individual organism possesses a phenotype that isn’t adapted to the environment, it may result in the individual’s inability to successfully compete. However, within the lifetime of one individual, new features cannot evolve in response to natural selection. Rather, natural selection operates only on populations over many generations.

38. Natural processes such as mutation, random genetic drift (alteration of genes by chance processes), and natural selection can lead to changes in a population’s gene pool ( sum of all genes among a population), but how does this result in the evolution of new species?

39. Natural selection that favors average individuals in a population Either extreme are chosen against Example – predators easily see the larger spiders and the small ones die because they find it difficult to find food

40. Natural selection that favors one of the extreme variations of a trait. The average and the other extremes are chosen against

41. Natural selection that favors both extremes of a trait’s variations The average organism chosen

42. Evolution of new species, can occur only when either interbreeding or the production of fertile offspring is somehow prevented. A species is defined as a group of organisms that look alike and have the ability to interbreed and produce fertile offspring in nature.

43. It occurs if a physical barrier separates a population into groups. Over time, each small population would adapt to the local environment through the process of natural selection. Eventually, the gene pools of each group would become so different that one could be considered a new species. Eg. Tree frogs that have been forced to separate because of drought in rain forests.

45. presence of multiple (an extra set) of chromosomes Is the result of mistakes that occur during meiosis. It’s estimated that nearly half of the known flowering plant species originated in this way, as well as crops such as wheat, cotton, apples, and bananas. Chrysanthemum: an Example of speciation Due to polyploidism.

46. GRADUALISM is the idea that species originate through a gradual change of adaptations. It is slow and steady Supported by fossil record PUNCTUATED EQUILIBRIUM idea that states that speciation occurs quickly in rapid bursts, with long periods of stability in between. Results from extreme environmental changes, such as warmer temperatures or the introduction of a new competitive species

48. Evolution in which species that once were similar to an ancestral species diverge Occurs when populations change as they adapt to different environmental conditions, eventually resulting in new species

49. Divergent evolution in which ancestral species evolve in a variety of species that fit diverse habitats

50. Evolution in which unrelated organisms evolve similar traits Occurs when unrelated species occupy similar environments and face similar selection pressures.

51. Small organic molecules joined to form larger molecules Genetic material originated Organic molecules aggregated into droplets Figure 22.4 (p. 514)

54. A phylogenetic tree

55. The process of fossilizaiton

56. Homologous structures

63. We are a class of organisms called Mammals

64. Nerve cord Vertebrae (backbone) Brain

65. Hair Long infancy (comparatively) Flexibility in responses due to large brain Produce milk (mammary glands)

67. Monkeys & Apes Physically and Biochemical similar

70. Chimps and Man Common ancestor about 5 million years ago

72. Upright walking Precision and Power grip Daytime color vision w/ depth perception More generalized teeth for omnivore diet Increase in brain size allows for new and abstract behavior

75. 60 mya- nighttime omnivores 40mya Daytime larger brains 35mya ancestor to monkeys and apes and humans

78. Roughly 200,000 years old (from H. erectus) 15,000 years in the Americas 35,000 years in Asia decline of Neanderthal 2 modes Multiregional hypothesis (humans from independent evolution in europe, asia, africa and Australia Out of Africa, one ancestor

79. Our evolution is cultural not morphological