Download Chapter 22 - cloudfront.net

Chapter 22
Interactive Question 22. 1
a. Match the theory or philosophy and its proponent(s) with the following
descriptions
A. catastrophism
B. Inheritance of acquired characteristics
C. Gradualism
D. Natural Selection
E. Taxonomy
F. Scale of nature
G. Uniformitarianism
a.
b.
c.
d.
e.
f.
g.
Aristotle
Cuvier
Darwin
Hutton
Lamarck
Linnaeus
Lyell
Answers
a.
1. E f
2. A b
3. B e
4. C c, d, g
5. F a
6. D c
7. G g
b. 5,1,2,4,3,7,6
Interactive Question 22.2
Summarize in your own words Darwin’s theory of natural selection as the mechanism of
evolution.
Answer: The excessive production of offspring sets up the struggle for existence; only a
small proportion can live to leave offspring of their own. Natural selection is the
differential reproductive success of individuals within a population that are best suited to
the environment, which leads over generations to greater adaptation of populations of
organisms to their environment.
Interactive Question 22.3
Within a few weeks of treatment with the drug 3TC, a patient’s HIV population consists
entirely of 3TC-resistan HIV. Explain how this rapid evolution of drug resistance is an
example of natural selection.
Answer: Treatment with the drug 3TC prevents most HIV from reproducing when their
enzyme reverse transcriptase inserts this cytosine mimic into its DNA, halting replication
and production of new HIV. The 3TC-resistant HIV have a version of reversetranscriptase that discriminates between cytosine and 3TC, and they are still able to
reproduce. With HIV’s short generation time, it takes very little time for 3TC-resistant
HIV to be strongly selected for by this drug and 100% of a patient’s HIV population to be
3TC resistant.
Interactive Question 22.4
Complete the following concept map that summarizes the main sources of evidence for
evolution
Answers
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
biogeography
fossil record
homologies
island species and mainland species or neighboring species in different
habitats
ancestral and transitional forms
homologous structures
embryological development
molecular comparisons
DNA and proteins
Descent from a common ancestor
Structure Your Knowledge
1. Briefly state the main components of Darwin’s theory of evolution
Answer: The two major components of Darwin’s evolutionary theory are that all life has
descended from a common ancestral form and that this evolution has been by natural
selection. The theory of natural selection is based on several key observations and
inferences. The overreproduction of offspring in conjunction with the limited resources
leads to a struggle for existence and the differential reproductive success of those
organisms best suited to the local environment. The unequal survival and reproduction of
the most fit individuals in a population leads to the gradual accumulation of adaptive
characteristics in a population.
Test Your Knowledge
Multiple Choice: Choose the best answer
1. b. taxonomy p.439
2. c. paleontology p.440
3. e. local catastrophic events such as droughts or floods p.440
4. a. the gradual accumulation of adaptations to changing or different environments
p.445 - 446
5. c. the reproductive success of the members of a population best adapted to the
environment p.445 - 446
6. a. are vestigal structures p.448
7. e. fossils of extinct whales found in Egypt and Pakistan that had small hind limbs
p.448
8. d. molecular biology p.449
9. d. a population p.450
10. d. Many adaptive traits may be acquired during an individual’s lifetime, helping
that individual to evolve p.445 - 446
11. c. Insects and vertebrates diverged from a common ancestor more recently than
did yeasts and molds p.450
12. e. Mendel’s paper in which he described his “laws of inheritance” p.442 - 443
13. b. Bats and humans evolved in the same geographic area p.448
14. d. found only in that location and nowhere else on Earth p.450
15. c. similarities between the marsupial sugar glider and the eutherian flying squirrel
p.450
16. c. the two groups share relatively recent common ancestor p.450