3. 2006-2007 Insect eaters Bud eater Seed eaters Cactus eater Warbler finch Tree finches Ground finches Chp. 14-3 The Theory of Evolution

4. I.Scientific Theory A. Greeks believed organisms resulted from evolution but no proof B. Mid 1800s Darwin & Wallace proved that evolution occurred C. Scientific theory 1. an explanation that something has gone under many tests 2. many theories are in science a. evolution b. cell theory c. germ theory

5. II. Darwin’s Travels and observations A. Charles Darwin travel the world from 1831-1836 1. studied fossils and rock formations 2. found similar organisms in different rock formations 3. noted that similar organisms had gone under change & answer that species do change 4. he collected and made sketched if plants/animals

6. 5.came up with ideas of how evolution occurs a. shared his ideas w/ other scientists but did not publish work right away i. when he heard of Wallace’s adventures, hurried to publish book “The Origin of Species” B.Alfred Wallace traveled to South America and East Indies 1. collected info on organism 2. formed an explanation of evolution – similar to Darwin’s

7. III. Darwin’s Theories A. Hypothesis 1. a testable explanation of a questions or problem 2. Darwin’s hypotheses was tested and much evidence was found to support him 3. Darwin’s hypotheses were stated as 2 theories a. first i. Descent with modification b. second i. Natural selection

8. An explanation of something that needs to go under many tests is known as a 1.hypothesis 2.theory 3.guess 4.pain

9. Who helped Darwin prove evolution occurred? 1.Newton 2.God 3.Wallace 4.Charles

10. Who published a book titled, “The Origin of Species?” 1.Darwin 2.Wallace 3.Both Darwin and Wallace 4.Neither Darwin and Wallace

11. What is a testable problem or question? 1.A theory 2.A hypotheses 3. a guess 4.Life

12. How many theories did Darwin’s hypothesis make? 1.1 2.2 3.3 4.4

13. IV.Decent with modification A. Theory states that more recent species found in the fossil record are changed descendants of earlier species 1. *** today’s species are related to those of the past 2. *** evolution occurs in nature B. Darwin observed this when visiting the Galapagos Islands of South America

14. Galapagos Recently formed volcanic islands. Most of animals on the Galápagos live nowhere else in world, but they look like species living on South American mainland. 800 km west of Ecuador

15. Many of Darwin’s observations made him wonder… Why? Darwin asked: Why were these creatures found only on the Galapagos Islands? Darwin found…many unique species

16. present day Armadillos Darwin found: that creatures have changed over time Evidence that creatures have changed over time ancient Armadillo Darwin asked: Why should extinct armadillos & modern armadillos be found on same continent? Darwin found…clues in the fossils

17. Darwin found: Different shells on tortoises on different islands Darwin asked: Is there a relationship between the environment & what an animal looks like?

18. Darwin found… birds Darwin found: Many different birds on the Galapagos Islands He thought he found very different kinds but He thought he found very different kinds but Darwin was amazed to find out: All 14 species of birds were finches… Yellow warblerWoodpecker finch Small ground finch Cocos Island Finch

19. Sparrow? Warbler? But there is only one species of finch on the mainland! Darwin asked: If the Galapagos finches came from the mainland, why are they so different now?

20. Finch?Sparrow? Woodpecker? Warbler? The finches cinched it! Large ground finch Small ground finch Warbler finchTree finch Darwin said: Ahaaaa! A flock of South American finches were stranded on the Galapagos… Darwin found: The differences between species of finches were associated with the different food they ate. different beaks are inherited variations serve as adaptations that help birds compete for food these birds survive & reproduce pass on the genes for those more fit beaks over time nature selected for different species with different beaks

21. Relationship between species (beaks) & food

22. Darwin’s finches Darwin’s conclusions –variations in beaks differences in beaks in the original flock adaptations to foods available on islands –natural selection for most fit over many generations, the finches were selected for specific beaks & behaviors –offspring inherit successful traits accumulation of winning traits: both beaks & behaviors –separate into different species

23. Warbler finch Woodpecker finch Small insectivorous tree finch Large insectivorous tree finch Vegetarian tree finch Cactus finch Sharp-beaked finch Small ground finch Medium ground finch Large ground finch Insect eaters Bud eater Seed eaters Cactus eater Warbler finch Tree finches Ground finches variation natural selection for best survival & reproduction From 1 species to 14 species…

24. V. Natural Selection –this theory explains how evolution occurs –environmental conditions influence which organisms survive –according to natural selection the organisms that are best suited for the environment are more likely to survive –some may adapt to survive – this process results in the evolution of a new species –Affects all populations of organisms Adaptation – the changing of a species in response to its environment

25. C. Ex – snakes have a specialized upper tooth 1.young snakes use this tooth to cut their way out if their shell and leave it with ease a. adaptive advantage i. having a greater chance to survive because of their characteristic 2. young snakes w/o this characteristic are not able to survive and unable to reproduce and the gene is lost the population

26. VI. Evidence of Evolution A. if populations change then evident should be present 1. fossil records show recent species are slightly different from earlier species 2. some organism’s embryos go through similar stages of development a. a human embryo has a tail and gill pouches as like a fish embryo all vertebrate embryos have a “gill pouch” at one stage of development

27. 3. vestigial structures a.a body part that appears to be useless, however was helpful to ancestors 1. snakes/whales have remnants of leg/pelvic bones – believed to be leftover from when ancestors had legs for walking 2006 fossil discovery of early tetrapod 4 limbs Missing link from sea to land animals

28. Vestigial organs Hind leg bones on whale fossils Why would whales have pelvis & leg bones if they were always sea creatures? Because they used to walk on land!

29. 4. homologous structures (*** see page 374) a. body parts that are similar to related organisms b. thought to have first appeared in an ancestor that is common and had front limbs

30. Which theory states that today’s species are related to those from the past? 1.Descent with modification 2.Natural selection 3.Both 4.Neither

31. Which theory occurs in nature? 1.Descent with modification 2.Natural selection 3.Both 4.neither

32. Which theory states environmental factors influence the species survival? 1.Descent with modification 2.Natural selection 3.Both 4.neither

33. Which theory states a species will adapt to live? 1.Natural selection 2.Descent with modification 3.Both 4.Neither

34. A body part that appears useless now but was once needs by ancestors is a 1.Vestigial system 2.Vestigial structure 3.Homologous structure 4.Any of the above

35. Where was Descent with modifications observed? 1.US 2.Europe 3.Galapagos Islands 4.Hawaiian Islands

36. ASSIGNMENT: - embryo w/s - page 375 review questions # 1 – 5 - w/s 14 - 3