Download Ch. 13 How Populations Evolve packet-2007

Ch. 13 How Populations Evolve
Name _____________________________
Period _________
California State Standards covered by this chapter:
Evolution
7. The frequency of an allele in a gene pool of a population depends on many factors and may be stable or unstable over
time. As a basis for understanding this concept:
a. Students know why natural selection acts on the phenotype rather than the genotype of an organism.
b. Students know why alleles that are lethal in a homozygous individual may be carried in a heterozygote and thus
maintained in a gene pool.
c. Students know new mutations are constantly being generated in a gene pool.
d. Students know variation within a species increases the likelihood that at least some members of a species will
survive under changed environmental conditions.
8.
Evolution is the result of genetic changes that occur in constantly changing environments. As a basis for
understanding this concept:
a. Students know how natural selection determines the differential survival of groups of organisms.
b. Students know a great diversity of species increases the chance that at least some organisms survive major
changes in the environment.
c. Students know the effects of genetic drift on the diversity of organisms in a population.
d. Students know reproductive or geographic isolation affects speciation.
e. Students know how to analyze fossil evidence with regard to biological diversity, episodic speciation, and mass
extinction.
Read the appropriate section in the textbook and lecture notes before answering the following questions. You must
put all answers and definitions into your own words for full credit.
Charles Darwin and The Origin of Species
1. natural selection:
2. evolutionary adaptation:
3. evolution:
4. Describe Lamarck’s proposed theory of evolution, The Theory of Acquired Traits.
5. Darwin’s phrase for evolution, ____________________ with __________________, captured the idea
than an ancestral species could diversify into many descendant species by the accumulation of different
_____________________ to various environments.
6. Explain what Darwin meant by “descent with modification”.
Evidence for Evolution
7. Define the evidence for evolution and give a specific example of each that supports the theory.
Form of
Definition
Example
Evidence
a) Fossil Record
b) Biogeography
c) Comparative
anatomy
d) Comparative
embryology
e) Molecular
biology
8. Explain how the 5 pieces of evidence are used to support the theory of evolution:
Evidence:
a) Fossil record
b) Biogeography
c) Comparative
anatomy
d) Comparative
embryology
e) Molecular biology
How it supports the theory of evolution:
9. homologous structures:
10. vestigial structures:
11. Name the category of evidence to which each of the following examples belongs.
Example
a. Fertilized eggs of earthworms, insects, and snails all go
through the same pattern of cell division.
Category
_____________________________
b. Remains of upright-walking but small-brained apes have
been found in Africa.
_____________________________
c. All animals with backbones have 12 pairs of nerves
extending from the brain.
_____________________________
d. The DNA of humans and chimpanzees is about 95%.
_____________________________
e. A protein called albumin is very similar in dogs and
wolves, and less similar in dogs and cats.
_____________________________
f. Animals called trilobites were common in the oceans 300
million years ago, but they have been extinct for millions of
years.
_____________________________
g. The farther an island is from the mainland, the more
different its plants and animals are.
_____________________________
Natural Selection
12. Describe Darwin’s key observations that led to his theory of natural selection.
a.
b.
13. Explain Darwin’s Theory of Natural Selection. Be specific.
14. Describe an example found in nature that supports this idea of natural selection (you could use your
own example or either the land snails or the pepper moth).
Modern Synthesis: Darwinism meets Genetics
15. population:
16. Define each term and explain how each of the following can lead to genetic variation:
Source of Genetic
Variation
Definition
How it leads to genetic variation.
a) Mutation
b) Sexual
recombination
17. gene pool:
18. Microevolution is a change in the frequency of __________________ in a population’s gene pool.
Evolving populations result from one or more of the following conditions (which are contrary to the
Hardy-Weinberg Equilibrium):
1. The population size is small.
2. The population is not isolated. Individuals migrate in and out of the population.
3. Mutations change the gene pool.
4. Mating is not random. Mates are selected by their traits.
Mechanisms of Microevolution
19. Describe the potential causes of microevolution and give specific examples of each.
Potential
Description
Examples
Cause
a) Genetic
drift
b) Gene
flow
c) Mutation
d) Natural
selection
20. bottleneck effect:
give an example:
21. founder effect:
give an example:
22. ________________________ is the original source of genetic variation in a population, but in a sexual
population with a relatively long generation span, most of the variation we observe is due to
__________________________.
23. Endangered species often have reduced genetic variation. Why might new strains of pathogens pose a
greater threat to cheetah populations than to mammalian populations having more genetic variation?
24. In Darwin’s “survival of the fittest”, what is used to measure “fitness”?
25. Describe the 3 main modes of natural selection. Give an example of each mode.
Mode of
Natural
Description
Example
Selection
a) Stabilizing
selection
b) Directional
selection
c) Diversifying
selection