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15-3: Darwin Presents His Case (p.378-386)
Publication of On the Origin of Species (p. 378–379)
1. The naturalist whose essay gave Darwin an incentive to publish his own work was _______________________________
2. Darwin described natural selection and presented evidence that evolution has been taking place for millions of years in his
book __________________________________________ published in __________.
Inherited Variation & Artificial Selection (p. 379)
3. Heritable differences among individuals of a species are referred to as ___________________ ____________________,
which we now know is caused by variations in the organisms’ ______________.
4. __________________________ _______________________ takes place when humans select natural variations (traits)
found in plants and animals for breeding.
Evolution by Natural Selection (p. 380–382)
5. What does the struggle for existence mean? ____________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
6. An organism’s __________________ refers to its ability to survive and reproduce in its specific environment and is a
result of _________________________, inherited characteristics that increase an organism’s chance for survival.
7. True/False. Adaptations can be anatomical (structural), physiological (functional), or behavioral.
8. Darwin referred to the fact that individuals best suited to their environment survive and reproduce most successfully as
__________________ ____ ______ _____________ or ____________________ _____________________.
9. Over time, what does natural selection result in? ________________________________________________________
______________________________________________________________________________________________
10. Circle the letter of each sentence that is true about natural selection.
a.
b.
c.
d.
It selects traits that increase fitness.
It takes place without human control.
It can be observed directly in nature.
It leads to an increase in a species’ fitness.
11. The principle that living species descend, with changes, from other species over time is referred to as
_____________________________________________________________.
12. What is the principle of common descent? _____________________________________________________________
______________________________________________________________________________________________
Evidence (p. 382–385)
13. Evidence supporting the theory of evolution can be found in:
a.
b.
c.
d.
14. What are fossils? _________________________________________________
15. What do transitional fossils do? ______________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
16. After observing similarities in the different species of finches on the Galapagos islands, what did Darwin decide/conclude?
______________________________________________________________________________________________
______________________________________________________________________________________________
17. What caused animals on different continents around the world to evolve common features? _______________________
______________________________________________________________________________________________
18. Structures that have different mature forms but develop from the same embryonic tissues are called
___________________________ ____________________________.
19. True/False. Homologous structures provide strong evidence that all four-limbed vertebrates have descended, with
modifications, from common ancestors.
20. Organs that are so reduced in size that they are just vestiges, or traces, of homologous organs in other species are called
_________________________ ____________________ .
Summary of Darwin’s Theory (p. 386)
21. Circle the letter of each idea that is part of Darwin’s theory of evolution.
a. There is variation in nature.
b. Fewer organisms are produced than can survive.
c. There is a struggle for existence.
d. Species change over time.
Strengths and Weaknesses (p. 386)
22. Evolution is often called the “________________________________________________________________.”