Download Biology 2002 - Spring Branch ISD

Biology I Pre-AP
Hiler
Unit 9: Evolution - Chapters 15 & 16
A. Darwin (chapter 15)
1. At this point in our study of biology, you probably recognize that there are many more
living organisms than you thought and that they vary tremendously in their
characteristics. Evolution is a process that helps to explain this diversity. Define
evolution.
2. Who was Charles Darwin? Briefly describe what you learned about his life and his
contribution to science. Read about his observations from his travels around the world.
What types of observations did he make? (p.370-371)
3. Review the timeline on page 374-5. In what ways do the events depicted here influence
Darwin?
4. How is the work of Lamarck different from Darwin’s ideas?
5. What other scientist shared many of Darwin’s thoughts? This scientist prompted Darwin to
publish his findings in what book?
6. Darwin came up with the term artificial selection. What does this mean?
7. Explain each of the following Darwin ideas:
a. struggle for existence
b. survival of the fittest / natural selection
c. descent with modification
B. Evidence of Evolution: Discuss how each of the following is evidence of evolution:
a. Fossils
b. Geographic distribution of species
c. Homologous structures
d. Vestigial structures
e. Similarities in early development
C. Answer the following general questions concerning evolution:
1. Recall the video and explain Darwin's theory of evolution by natural selection and his “tree
of life” idea. How does his theory explain the diversity of life on earth today?
2. In the theory of evolution, the term adaptation refers to random genetic changes in the
DNA code of an organism, which increases an organism's ability to survive. (We often use
the term adaptation incorrectly. For example - "Johnny adapted to the cold climate when
he moved to Alaska." But since this did not result in a genetic change in Johnny's DNA, it is
not genetically transferred to offspring, and therefore does not affect the survival of the
species.) The variation in any given species is the result of random changes in DNA
(mutations). No organism can change its own DNA on demand to fit a new environmental
change.
a. Give three examples of adaptations specific organisms have today and
why they enable their survival.
3. Much more is known today about genetics than was understood during the lifetime of
Darwin. How has current knowledge of DNA changed the way evolution is studied?
Activity #1: NATURAL SELECTION ACTIVITY
Activity #2: MOLECULAR CONNECTION
Biology I Pre-AP
Hiler
D. Evolution of Populations (Chapter 16)
1. Individuals do not evolve, populations evolve. What does this mean? Include gene pool
and relative frequency in your answer.
2. Define evolution in genetic terms (see key concept p.394)
3. What are the sources of genetic variation observed in populations?
4. Natural selection on single gene traits leads to evolution by altering allele frequencies.
Explain how this applies to the lizard example on page 397 in your text.
5. Why is natural selection on polygenic traits different from natural selection on single gene
traits?
6. Define:
a. directional selection
b. stabilizing selection
c. disruptive selection
7. Study Figure 16-9 on page 400. How is this figure an example of genetic drift? What is the
effect on the evolution of populations?
8. What is the Hardy-Weinberg principle?
9. What are the 5 conditions required to maintain genetic equilibrium?
10. Read the “Issue in biology” p.403. How does the use of antibiotics cause the evolution of
bacteria?
Activity #3: HARDY-WEINBERG LAB
E. Speciation (chapter 16-3)
1. What factors lead to speciation (the evolution of different species)? Use the following to guide
you in your explanation:
i. Reproductive isolation
ii. Mechanisms for reproductive isolation
1. behavioral isolation
2. geographic isolation
3. temporal isolation
2. How has the work of Peter and Rosemary Grant supported the work of Darwin? p.406-407
3. Read “Speciation in Darwin’s Finches” and study Figure 16-16 on pages 408-9. Explain how
the vegetarian tree finch may have evolved.