Genetic Analysis: An Integrated Approach (3rd Edition)
3rd Edition
ISBN: 9780134605173
Author: Mark F. Sanders, John L. Bowman
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 20, Problem 24P
In the mouse, Musmusculus, survival in agricultural fields that are regularly sprayed with a herbicide is determined by the genotype for a detoxification enzyme encoded by a gene with two alleles, F and S. The relative fitness values for the genotypes are:
a. Why will this pattern of natural selection result in a stable equilibrium of frequencies of F and S?
b. Calculate the equilibrium frequencies of the alleles.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
A species of hummingbird feeds on nectar of a particular plant whose flowers
form a long, skinny cup. Beak length is a heritable trait that varies among
individual hummingbirds. The birds' beaks must be long enough to reach the
nectar, but longer beaks are also heavier and make flying more costly in terms of
energy.
a. Which mode of selection is this hummingbird species experiencing?
b. How does this mode of selection affect the mean and standard deviation
over time?
Assume that in a certain population of giraffes, dark brown spots are dominant to light brown spots. If the frequency of dark brown giraffes is 56%, what is the frequency of the dark brown allele? Hint: the frequency that is provided is the frequency of a specific phenotype (i.e. not a genotype frequency)
The three-spined stickleback (Gasterosteus aculeatus) is a species of fish that has both marine and freshwater populations. There are genetic differences between the populations in the different environments. The graph shows the frequency of a certain allele in freshwater and marine populations of stickleback fish. In 1978, scientists studied how the fitness of marine sticklebacks would be affected if they were introduced into a freshwater environment. They collected 90 male and 90 female sticklebacks from a marine population and 10 male and 10 female sticklebacks from a freshwater population. The 200 sticklebacks were introduced into a freshwater environment that had no stickleback fish previously. Which of the following best describes the likely results of the scientists’ investigation of the fitness of the sticklebacks that were originally from a marine environment?
Chapter 20 Solutions
Genetic Analysis: An Integrated Approach (3rd Edition)
Ch. 20 - 20.1 Compare and contrast the terms in each of the...Ch. 20 - In a population, what is the consequence of...Ch. 20 - 20.3 Identify and describe the evolutionary forces...Ch. 20 - Describe how natural selection can produce...Ch. 20 - Thinking creatively about evolutionary mechanisms,...Ch. 20 - 20.6 Genetic drift, an evolutionary process...Ch. 20 - Over the course of many generations in a small...Ch. 20 - Catastrophic events such as loss of habitat,...Ch. 20 - 20.9 George Udny Yule was wrong in suggesting that...Ch. 20 - 20.10 The ability to taste the bitter compound...
Ch. 20 - Figure 20.6 illustrates the effect of an ethanol ...Ch. 20 - 20.12 Biologists have proposed that the use of...Ch. 20 - 20.13 Two populations of deer, one of them large...Ch. 20 - 20.14 Directional selection presents an apparent...Ch. 20 - 20.15 What is inbreeding depression? Why is...Ch. 20 - 20.16 Certain animal species, such as the...Ch. 20 - Genetic Analysis 20.1 predicts the number of...Ch. 20 - 20.18 In a population of rabbits, and . The...Ch. 20 - Sickle cell disease (SCD) is found in numerous...Ch. 20 - 20.20 Epidemiologic data on the population in the...Ch. 20 - The frequency of tasters and nontasters of PTC...Ch. 20 - Tay-Sachs disease is an autosomal recessive...Ch. 20 - 20.23 Cystic fibrosis (CF) is the most common...Ch. 20 - 20.24 In the mouse, Mus musculus, survival in...Ch. 20 - 20.25 In a population of flowers growing in a...Ch. 20 - Assume that the flower population described in the...Ch. 20 - 20.27 ABO blood type is examined in a Taiwanese...Ch. 20 - 20.28 A total ofmembers of a Central American...Ch. 20 - 20.29 A sample offield mice contains individuals...Ch. 20 - Prob. 30PCh. 20 - Albinism, an autosomal recessive trait...Ch. 20 - 20.32 The frequency of an autosomal recessive...Ch. 20 - 20.33 Evaluate the following pedigree, and answer...Ch. 20 - Evaluate the following pedigree, and answer the...Ch. 20 - The following is a partial pedigree of the British...Ch. 20 - Draw a separate hypothetical pedigree identifying...Ch. 20 - Prob. 37PCh. 20 - 20.38 Achromatopsia is a rare autosomal recessive...Ch. 20 - 20.39 New allopolyploid plant species can arise by...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Consider a gene with two alleles, L and M, that exhibit complete dominance. The table below provides the relative fitnesses of the three genotypes in two populations. LL LM MM Population 1 0.8 0.3 0.3 Population 2 0.9 1.0 1.0 a. Which allele is dominant, and how do you know? b. Which allele will increase (in each population), and how do you know? c. In which population will the change in allele frequencies occur more quickly, and how do you know?arrow_forwardIn a species of snail (Snail 1), a locus has two alleles, A and B. The snail has populations on a continent and a small nearby island. The frequency of allele A on the continent is 0.7, and the frequency of allele A on the island is 0.2. If the migration rate, m, from the continent to the island is 0.1 (assume no migration from island back to continent), What is the change in the frequency of allele A after the first generation, compared to the original population?arrow_forwardIn a certain population of finches, a single gene controls beak length. There are two possible alleles: S, which leads to a short beak, and L, which leads to a long beak. Individuals with the genotype SS will have a short beak, individuals with the genotype LL will have a long beak, and individuals with the genotype SL will have a medium-length beak. Scientists measure that in this population of 1,128 total birds, 321 birds have short beaks, 562 have medium-length beaks, and 245 have long beaks. Ten years later, the measurements are repeated. This time, there were 1,346 birds in the population. 452 have short beaks, 699 have medium-length beaks, and 195 have long beaks. Based on the data collected 10 years later, is this population of finches currently evolving? How do you know? A. yes because more individuals in the population exhibit the SS genotype than would be expected if the population was in Hardy-Weinberg equilibrium B. no because the number of individuals that…arrow_forward
- Assume that the frequency of gene B in a hypothetical population Is 0.63, that there are only two alleles (B and b) of the gee in the population, that allele B is dominant over allele b, that neither allele has a selective advantage over the other, and that the population is at equilibrium with regard to this particular gene. What proportion of the population is expected to have the phenotype specified by the B allele according to the Hardy-Weinberg formula? 0.47 0.87 0.67 0.40 0.37arrow_forwardThe graph below shows values for body size in parents and offspring. The data shown are consistent with which of the following situations. ANSWER CHOICES A. variation in body size is completely due to variation in the environment (heritability is 0) B. most of the variation in body size is due to variation in the environment but there is a small effect of genes (heritability is around 0.2) C. variation in body size is completely due to variation in genes (heritability is 1.0) D. most of the variation in body size is due to variation in genes but there is some effect of the environment (heritability is about 0.8)arrow_forwardA population sample of 300 individuals is studied for the electrophoretic mobility of an enzyme that varies according to the genotype determined by 2 alleles, E and T of a single gene. The results are 7 individuals with genotype EE, 106 with genotype ET, and 187 with genotype TT. What are the allele frequencies of E and T, and what are the expected numbers of the 3 genotypes if random mating is assumed?arrow_forward
- Calculate selection for the following scenario. In a population of prairie dogs living on a prairie, prairie dogs with genotype aa have 8 offspring per year on average, those with genotype Aa have 4 offspring per year on average, and those with genotype AA have 3 offspring per year on average. Round selection to the nearest hundredth, report selection as a value ranging from "0.00" to "1.00" Selection on genotype Aa: Selection on genotype AA: Selection on genotype aa: Which genotype has the highest fitness? Fill in the blank with homozygous dominant, heterozygous, or homozygous recessivearrow_forwardA dominant mutation in Drosophila called Deltacauses changes in wing morphology in Delta/+ heterozygotes. Homozygosity for this mutation (Delta /Delta) is lethal prior to the adult stage. In a population of 150 flies, it was determined that 60 hadnormal wings and 90 had abnormal wings.a. What are the allele frequencies in this population?b. Using the allele frequencies calculated in part (a),how many total zygotes must be produced by thispopulation in order for you to count 160 viableadults in the next generation?c. Given that there is random mating, no migration,and no mutation, and ignoring the effects ofgenetic drift, what are the expected numbers ofthe different genotypes in the next generation if160 viable offspring of the population in part(a) are counted?d. Is this next generation at Hardy-Weinberg equilibrium? Why or why not?740 Chapter 21 Variation and Selection in Populationsarrow_forwardConsider a hypothetical beetle whose back abdomen pattern is determined by two alleles A1 and A2. Beetles that are homozygous for the 'A1' allele have solid coloring, beetles that are heterozygous (A1A2) are spotted, and beetles that are homozygous for the A2 allele are striped. You find a population of 100 of these beetles and count each phenotype (shown below). TRUE or FALSE: this population is in Hardy-Weinberg equilibrium? What is the predicted frequency of spotted beetle? Solid Beetles = 49 Spotted Beetles = 35 Striped Beetles = 16 asap pleasearrow_forward
- Imagine you are studying a population of finches on one of the Galápagos Islands. You have been recording many of the birds’ physical traits, including the length of both wings. You observe that for 80% of individuals measured, the length of the left wing is not significantly different from the length of the right wing (in other words, they are symmetrical). But for about 20% of birds measured, the wing lengths are asymmetrical. This distribution is true from generation to generation. Suddenly, a rare 5-day windstorm takes over the island. After the storm, you spend the next several days netting each bird on the island that survived the storm. You discover that 85% of the birds with symmetrical wings survived the storm, whereas only 5% of the birds with asymmetrical wings did. a. Propose a hypothesis to explain this observation. b. If such storms become increasingly common due to changes in climate, how might you expect the population to change over time with respect to wing symmetry?arrow_forwardA population of mealworm beetles (Tenebrio molitor) called the founder generation-consisting of 150 Black (MM) individuals, 100 Brown (Mm) individuals and 250 Orange (mm) individuals-is established on a remote region of Puerto Rico. Mating within this population occurs at random, the three genotypes are selectively neutral and mutations occur at a negligible rate. (a) What are the frequencies of alleles M and m in the founder generation? Frequency of allele M= Frequency of allele m= (b) Calculate p2, 2pq, q2 and the expected number of MM individuals, Mm individuals, and mm individuals in the population, assuming that the population is in Hardy-Weinberg equilibriumarrow_forwardIn a tropical species of butterfly, wing shape is controlled by a single gene. Individuals can have wide wings (WW), elongated wings(Ww), or reduced wings (ww) In one population you calculate the genotype frequencies are: * wide WW=0.75 *Elongated Ww=0.20 *reduced ww = 0.05 Wide shape affects fitness because predators are most successful at catching butterflies with reduced wings, although they also get some of the other phenotypes. After new predator colonizers the rainforest where this butterfly lives, the average number of offspring per butterfly is *wide WW=40 * elongated Ww=50 *reduced ww=80 What will be the genotype frequencies in the first generation of butterflies following natural selection due to the new predator? (ie you are looking for frequencies after selection and before reproduction) Round all values 2 decimal places A. wide WW=0.75, elongated Ww=0.20, reduced ww=0.05 B.Wide WW=0.68, elongated Ww=0.29, reduced ww=0.04 C.There is no way to know because natural selection…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education
What is Evolution?; Author: Stated Clearly;https://www.youtube.com/watch?v=GhHOjC4oxh8;License: Standard Youtube License