Darwin's Theory of Evolution: Key Principles and the Voyage of the Beagle

1. Biology Chapter 15 Evolution Unit: Darwin’s Theory of Evolution

2. IQ #1 Darwin’s Dangerous Idea • How long was Darwin on the Beagle? • What Island chain did he study? • What trait of finches did he observe variation in? • What theory did Darwin come up with? • Why will the best adapted organism continue to populate the earth? • What selects which organism will survive according to Darwin? • What do all organisms compete for? • Was Darwin’s theory well accepted at the time? • Can viruses adapt like organisms? What example is used to support this in the video? • What is an example of a complex structure developing slowly over a long period of time as shown in the video?

3. 15-1 The Puzzle of Life’s Diversity I. Background: Evolution and Its Core Principles • Evolution is a T. Zobzhansky: “Nothing in biology makes sense except in the light of evolution.” Central theme in biology

4. B. Core principles of evolution: Common ancestor 1. All life is linked through a ___________________ 2. Populations of living things ___________________ (evolve). 3. The _______________________ this change (natural selection) so that advantageous traits are selected over less advantageous traits. 4. The _________________________________ ____________________________________ (descent with modification). Change over time Environment influences advantageous traits become more common in the population

5. II. Voyage of the Beagle Darwin frame his theory of evolution. A. A sea voyage helped ____________________ 1. Darwin was born in England on February 12, 1809. 2. Set sail on the HMS Beagle from England in 1831 for a ____________ around the world. 5 year voyage

6. Darwin’s Journey

7. Tortoise Marine Iguana

8. 3. Darwin’s Observations: Patterns of Diversity a. ___________________: plants and animals seemed remarkably well suited to whatever environment they inhabited.

9. Living Organisms and Fossils b. ____________________________: Many of the fossils that Darwin discovered resembled living organisms but were not identical to them. For example, glyptodon, an extinct animal, is an ancient relative of the armadillo of South America. (page 370)

10. c. The Galapagos Islands: 1.) Located 1000 km west of South America. 2.) Islands were close together but had _________________ 3.) Hood Island had __________________. Tortoises on this island had _____________ and a curved shell allowing them to reach the sparse vegetation. 4.) Isabel Island had _________________. Tortoises on this island had _____________ and a dome-shaped shell. different climates sparse vegetation long necks rich vegetation shorter necks

11. 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

12. similarities and differences with mainland species 5.) Galapagos Finches: striking correlation between form of finches and the environment they inhabit;

13. Beak Adaptations

14. Small Tree Finch Large Ground Finch Woodpecker Finch

15. 15-2 Ideas That Shaped Darwin’s Thinking Aristotle I. Evolutionary Thinking before Darwin A. ________ believed that species were fixed and did not evolve. B. All species were created in a single act of creation about 6,000 years ago. C. Buffon (mid-1700’s) suggested that _______________________ and raised the possibility that different species ______________________________ Earth was much older arose from common ancestors.

16. II. An Ancient Changing Earth • Hutton (1785) • ________________ ________________ ________________ 2. Earth is much older than a few thousand years. Geological processes operate extremely slowly.

17. B. Lyell (1833) 1. Wrote Principles of Geology. 2. Promoted the idea of continual, gradual, consistent geological changes.

18. first to support the idea of evolution. C.Lamarck (1809) was the 1. Believed organisms acquired or lost certain traits during their lifetime. Example: giraffe 2. therefore, this led to a change in a species. Traits could be passed to offspring

19. Example: Giraffe

20. increase too fast D. Malthus (1798) 1. If human populations _______________, it would lead to competition for scarce resources, and 2. only some individuals would survive. Limits to population growth.

21. E. Wallace (1858) 1. Conceived of essentially the same theory as Darwin. 2. Speculates on evolution by natural selection.

22. 15-3 Darwin Presents His Case I. Publication of On the Origin of Species A. Wallace’s letter outlining basic principles of natural selection spurs Darwin into taking his ideas public.

23. B. After much fierce debate, Darwin publishes his theory in 1859. • Contains a well-constructed • Backed by • He used the phrase • The book is “sold out” in one day. argument for natural selection. considerable evidence. “descent with modification.”

24. C. Advances in genetics in the twentieth century yield the mechanism through which natural selection operates, vindicating Darwin’s ideas. DNA Fingerprinting

25. II. Inherited Variation and Artificial Selection • Nature provided the variation, B. Variation existed both in nature and in farms. This variation was inherited. 1. Cows that __________________________ were selected by breeders. 2. Plants that __________________________ were selected. and humans selected those variations that they found useful. produced the most milk produced the largest and most flavorful fruit

26. Artificial Selection: Dogs

27. Artificial Selection: Plants

28. III. Evolution by Natural Selection High birth rates and a shortage of life’s basic needs A. The Struggle for Existence 1. would force organisms to compete. 2. Result: or better protected, such as a porcupine can . Those predators that are faster or have a better mechanism to catch prey survive. Those prey that are better camouflaged, avoid being caught

29. B. Survival of the Fittest ability of an organism to survive and reproduce. • Fitness – 2. Darwin proposed that 3. Adaptation – any _________________ characteristic that increases an organism’s chance of survival. fitness is a result of adaptation. inherited

30. Examples of Adaptations a. Waxy coating on the surface of leaves prevents against water loss • Ability to climb trees - spider monkey - Tree boa • Coloration - Octopus

31. Look closely: It’s an Insect! 4. Those individuals and reproduce most successfully. Darwin called this process “survival of the fittest” or best suited to their environment survive natural selection. Mantids exhibit camouflage.

32. C. Descent with Modification 1. 2. Common descent: all species –__________________– were derived from common ancestors. 3. All living organisms are related to one another. living and extinct A single “tree of life” links all living things.

33. The “Tree of Life”

34. The “Tree of Life”

35. IV. Evidence of Evolution

36. Strata of sedimentary rock at the Grand Canyon.

37. Figure 17-2 Formation of a Fossil Section 17-1 Water carries small rock particles to lakes and seas. Dead organisms are buried by layers of sediment, which forms new rock. The preserved remains may later be discovered and studied. Go to Section:

38. Formation of sedimentary rock and deposition of fossils from different time periods.

39. Leaf Fossil Insect in Amber Ammonites Dinosaur Fossil

40. IV. Evidence of Evolution

41. Darwin’s Finches

42. The continent of Australia is home to unique animals, such as these marsupials, that evolved in isolation.

43. IV. Evidence of Evolution

44. Overuse of Antibiotics has lead to Antibiotic Resistance in bacteria. Evolution of Pesticide Resistance in insect populations.

45. IV. Evidence of Evolution

47. Evolution Evidence: Comparative Anatomy • Homologous structures (homology) • Descent from a common ancestor • Vestigial organs Ex: whale/snake hindlimbs; wings on flightless birds

48. Comparative Anatomy: Whale hind limb Fossilized leg bones of Basilosaurus, an ancient whale. A transitional fossil linking past and present.

49. Whales are mammals that evolved from land dwellers.