Download Test Review on Evolution and Populations

Test Review on Evolution and Populations
1. Linnaeus based his classification on what 3 things? Common structures, fossil
record, common ancestry
2. Know the work of Lyell, Darwin, Lamarck, Aristototle, Curvier, and Hutton.
Aristotle- fixed species that increase in complexity; Lyell- uniformitarismmechanisms of change are constant over time, changes in Earth’s surface occur
slowly over time; Lamarck- acquired traits can be passed on, use and disuse,
Cuvier- catastrophism- opposed evolution, sudden events occurred in the past that
caused changes. Cuvier, Linnaeus, and Aristotle’s beliefs opposed Darwin’s.
Hutton said that Earth’s geologic features could be explained by gradual
mechanisms still operating, such as valleys forming from river flow.
3. Who’s theory was closest to Darwin’s? Wallace’s
Prior to Darwin people believed that Earth was a few thousand years old and
populations were unchanging.
4. What did Darwin find out about finches in the Galapagos? The finches had
variations that were selected for by the environment they lived in. For example,
they finches with beaks that could crush seeds survived because there were a lot of
seeds to eat on the Island.
5. Explain resistance to antibiotics or pesticides. Offspring that are genetically
resistant will survive and reproduce.
6. What are homologous structures? Name 3. They are structures of similar
embryonic origin. They may have different functions. Ex. Human arm, wing of a
bat, bird wing, a fin of a whale, dolphins (cetaceans).
7. What is the strongest evidence of common ancestry? All organisms share a
common genetic code.
8. Explain natural selection.
a. Members of a population vary in their traits.
b. Traits are inherited from parents
c. Species produce more offspring than survive
d. Resources and the environment influence survival
9. _Catastrophism_ was Cuvier’s way of explaining the fossil record.
10. Lamarck said __”use and disuse” and acquired traits are passed on.
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11. Biogeography- similar species are found and distributed throughout the planet
because the Earth was once one landmass.
12. What other naturalist devised the concept of natural selection? Wallace
13. Darwin was the first to propose a mechanism for evolution supported by evidence.
14. Evolution states that the more closely 2 organisms are related, the more recently
they shared a common ancestor.
15. Natural selection does not state that individuals MUST adapt to their environment.
16. The most fit individuals leave the most fit offspring.
17. Are variations in populations ever caused by the environment? Yes, but not
because of need. The environment puts pressure on organisms and only the most
fit survive.
18. What changes have been observed in humans over time? Skip (taller, larger skulls,
less dense bones)
19. Why do resistant bacteria strains become predominant? Those bacteria that have a
genetically resistant survive and reproduce, while the susceptible bacteria die. This
is true of pesticides and insects too.
20. Humans, whales, and cats have many of the same bones that we call homologous
structures. This proves that these animals share a common ancestor.
21. When an organism loses a structure that it doesn’t use, this means that those
structures must have presented greater costs to the organisms than benefits.
22. All organisms share the same genetic code.
23. The spleen is no longer considered a vestigial organ because it functions in
immunity and destroying old blood cells.
24. Darwin didn’t understand genetics when he did his work. There was not an
understanding of DNA and genetics at that time. He didn’t know about gene
frequency in populations.
25. What can you conclude about frequencies that don’t change? They are in HardyWeinberg equilibrium
26. List the criteria required for Hardy Weinberg to be true.
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a.
b.
c.
d.
e.
Large population
Not gene flow
No natural selection
Random mating
No mutations
27. 52% of the animals in a population are aa. What is the frequency of the recessive
allele? The dominant allele? Heterozygotes?
a. q 2= .52 q = .72 p= .28 p 2= .08 2pq= .40
28. If the frequency of little a in a population is 0.9, what is the frequency of
heterozygous individuals? What percentage would this be?
a. q = 0.9 p= 0.1
2pq= .18
29. Why do harmful recessive alleles remain in populations? Because the
heterozygous individuals survive.
30. If 54% of the population is heterozygous for a trait, what would the frequency of
homozygotes be? 46%
31. 1000 people have been blood typed. 140 are AA, 460 are AB, and and 400 are
BB. That means there are 2000 alleles in the population.
32. What is the frequency of A? AA= 140 x2= 280
AB = 460x1=460
280 +460= 740/2000 alleles = 0.37
33. B? BB= 400x2= 800 plus AB = 460 x1= 460
800+460= 1260/2000= .63
34. O? I will either ask for A or B. If you calculate the frequency of B to be 0.63,
then the recessive frequency (O)= q= 0.37
35. If there were 2000 children born to this generation, how many would be AB?
2(.63)(.37)= 0.47 x 2000= 940
36. If T = tall and t= short in pea plants, and there are 42 purple flowers and 36 white
flowers, what is the frequency of q? SKIP
37. Circle the following that are due to chance: sexual recombination, bottleneck,
founder effect, mutation, and natural selection.
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38. If a generation of Amish are displaying an increase in a bad recessive gene, what
should the population do? They experience this due to genetic drift, bottleneck,
and founder effect. They need to get new genes in their population.
39. Whenever bottleneck effect occurs, what other process would follow? Genetic
drift, founders effect, and microevolution could follow.
Sources of variation include crossing-over, Independent Assortment, Random
Fertilization, and mutations.
40. Gene flow occurs through populations. The more migration the < > evolution.
(greater)
41. Cline- a change in a population due to drastic changes in the environment, such as
plants decreasing in size as the altitude increases.
42. Genetic drift occurs when small populations reproduce. This can be due to
founder effect, bottleneck effect, or choice.
43. Random selection44. directional selection- when a phenotype of a population changes to one extreme or
another.
45. stabilizing selection- this removes extreme variants from the population and
preserves the intermediate types.
46. disruptive selection- favors variants at both ends of the distribution.
47. sexual selection- a form of natural selection when individual characteristic are
considered to be more desirable by a mate.
1. Having greater fitness means that surviving and passing genes on to offspring.
2. If 59% of the animals in a population display the recessive trait aa, what is the
estimated frequency of allele a in the pool? a= 0.77= q
p= 0.23
3. Aa? 2 (0.77)(0.23)= 0.35
4. What is the relative fitness of a lethal recessive allele? It would have little relative
fitness if the individual did not survive and reproduce to pass on its genes.
5. What is the founder effect? When a population size decreases due to movement of
the population or bottleneck effect. It can lead to genetic drift.
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6. Compare directional selection and diversitfying selection. Directional favors
extreme variants; diversifying favors 2 extremes without individuals with middle
variation.
7. Define: random selection, directional selection, stabilizing selection, diversifying
selection, artificial selection and sexual selection. Be able to apply these
definitions to examples that I give you. See above.
8. Name the prezygotic and post-zygotic barriers. Prezygotic barriers prevent mating
by isolation, such as habitat isolation, temporal isolation, behavioral isolation,
mechanical isolation, and gametic isolation. Post-zygotic barriers reduce hybrid
viability, reduce hybrid fertility, or result in hybrid breakdown.
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