Chapter 15: The Theory of Evolution

1. The modern theory of evolution is the fundamental concept in biology.

2. Evolution is the change in populations over time.

3. Fossil evidence formed the basis of early evolutionary concepts.

4. The ideas first published by Charles Darwin are the basis of modern evolutionary theory.

5. Darwin observed that the traits of individuals vary in populations.

6. Variations are then inherited.

7. Breeding organisms with specific traits in order to produce offspring with identical traits is called artificial selection.

8. Name three organisms that have evolved through artificial selection.

9. Natural selection occurs when organisms with favorable variations survive, reproduce, and pass their variations to the next generation.

10. Organisms without these variations are less likely to survive and reproduce.

11. As a result, each generation consists of offspring from parents with these variations that aid survival.

12. Darwin published the first book about evolution called On the Origin of Species in 1859.

13. The ideas detailed in Darwin’s book are a basic unifying theme of biology.

14. Evolutionary processes are difficult for humans to observe directly.

15. The short scale of human life spans makes it difficult to comprehend evolutionary processes that occur over millions of years.

16. An adaptation is any variation that aids an organism’s chances of survival.

17. Name three human adaptations.

18. According to Darwin’s theory, adaptations in species develop over many generations.

19. Mimicry is a structural adaptation that enables one species to resemble another species.

20. Describe one example of mimicry.

21. Another subtle adaptation is camouflage, an adaptation that enables species to blend with their surroundings.

22. Describe one example of camouflage.

23. Fossils are an important source of evolutionary evidence because they provide a record of early life and evolutionary history.

24. Although the fossil record provides evidence that evolution occurred, the record is incomplete.

25. Evolutionary biologists view structural similarities as evidence that organisms evolved from a common ancestor.

26. It would be unlikely for so many animals to have similar structures if they each arose separately.

27. Structural features with a common evolutionary origin are called homologous structures.

28. Describe an example of homologous structures.

29. The body parts of organisms that do not have a common evolutionary origin but are similar in function are called analogous structures.

30. Describe an example of analogous structures.

31. A vestigial structure is a body structure in a present-day organism that no longer serves its original purpose, but was probably useful to an ancestor.

32. Give an example of a vestigial structure.

33. An embryo is an early stage of growth and development of plants and animals.

34. The embryos of a fish, a reptile, a bird, and a mammal all have a tail and pharyngeal pouches. This suggests evolution from a common ancestor.