The document discusses key concepts and evidence related to Darwin's theory of evolution by natural selection. It describes how Darwin observed adaptations in species on the Galapagos Islands and how this insight, combined with evidence from fossils, biogeography, embryology and anatomy, led him to propose natural selection as the mechanism of evolution. Natural selection acts on inherited variation in traits, with those conferring greater fitness being passed on to more offspring over generations of descent with modification.

1. KEY CONCEPT There were theories of biological and geologic change before Darwin.

4. Buffon: species shared ancestors rather than arising separately

5. E. Darwin: more-complex forms developed from less-complex forms

7. catastrophism

8. gradualism

10. Darwin observed differences among island species. Variation is a difference in a physical trait. Galápagos tortoises that live in areas with tall plants have long necks and legs. Why would that be an advantage? Galápagos finches that live in areas with hard-shelled nuts have strong beaks. Why would that be an advantage?

15. What term describes the theory that natural disasters shaped Earth's landforms and caused species to become extinct? A. Gradualism B.Uniformitarianism C.Catastrophism D. Evolution

16. What term describes the theory that natural disasters shaped Earth's landforms and caused species to become extinct? A. Gradualism B.Uniformitarianism C.Catastrophism D. Evolution Correct Answer = C What must be true of two individuals of the same species? A. They can reproduce and have fertile offspring. B. They must live in the same environment. C. They can reproduce, but their offspring are not fertile. D. They can pass acquired characteristics to their offspring.

17. What term describes the theory that natural disasters shaped Earth's landforms and caused species to become extinct? A. Gradualism B.Uniformitarianism C.Catastrophism D. Evolution Correct Answer = C What must be true of two individuals of the same species? A. They can reproduce and have fertile offspring. B. They must live in the same environment. C. They can reproduce, but their offspring are not fertile. D. They can pass acquired characteristics to their offspring. Correct Answer = A

18. Review Evolution is the process of change resulting in descendents that are different from their ancestors. A species is a group of organisms that can reproduce to form viable offspring. Variation is difference in a physical trait. Adaptation is a feature that allows an organism to better survive in its environment Adaptations can lead to a genetic change in a population. Fossil evidence and observation of adaptations led to Darwin’s understanding of life’s evolution.

19. KEY CONCEPT Darwin proposed natural selection as a mechanism for evolution.

21. There is a struggle for survival due to overpopulation and limited resources.

25. adaptation

30. similar embryos, diverse organisms

33. Analogous structures have a similar function.Analogous structures are not evidence of a common ancestor. Why?

36. What adaptations did Darwin see in the tortoises of the Galapagos Islands? Shape of beak B. Length of neck and legs C. Shape of head D. Kind of shell Correct Answer = B What did the variations in the Galapagos finches seem to be well suited to? The animals' size B. The animals' age C. The island the animals lived on D. The animals' environment and diet

37. What adaptations did Darwin see in the tortoises of the Galapagos Islands? Shape of beak B. Length of neck and legs C. Shape of head D. Kind of shell Correct Answer = B What did the variations in the Galapagos finches seem to be well suited to? The animals' size B. The animals' age C. The island the animals lived on D. The animals' environment and diet Correct Answer = D

39. There are four principles of natural selection

40. Variation

41. Overproduction

42. Adaptation

43. Descent with modification

45. Embryology shows evidence of evolution

46. Anatomy shows evidence of evolution

47. Homologous structures – similar structure, different function. Suggests common ancestor

48. Analogous structures – similar function. Does not suggest common ancestor

49. Vestigial structures give hints to ancestry and history of species