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
Videos
Textbook Question
Chapter 20, Problem 4P
Describe how natural selection can produce balanced polymorphism of allele frequencies through selection that favors heterozygotes.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Selection confers a reproductive advantage to individuals based on their adaptations, and therefore causes the alleles carried by those individuals to increase in the population. Selection can be simulated by having your partner remove any three individuals of a particular suit as you deal the cards into a pile. The fitness of that variant is therefore 0.77 (10/13 survive), while the fitness of the other three variants remains at 1.0 (13/13 survive). Recalculate allelic (suit) frequencies after selection.
1. What is the effect of selection on reproduction, allelic diversity, and frequency?
2. What would happen if similar selection continued over several generations?
Cite references.
Explain how Darwinian evolution can decrease and increase the frequency of an allele or a more complex heritable trait
in sheep, black wool is determined by a Dominant Allele (B) and white wool by a Recessive Allele (b). In a population of 200 sheep, 128 of them exhibit the dominant trait of having black wool and the rest have the recessive trait of white wool. Calculate the frequencies of both the (B) and (b) alleles. Calculate the frequencies of homozygous dominant vs.heterozygous sheep, as well as the homozygous recessives individuals.
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
- Selection may also act against heterozygotes. How do allele frequencies change if the two homozygotes have equal fitness, but heterozgotes have a 50% reduced fitness? Explain what happens and whyarrow_forwardSuppose in a certain population there are 100 individuals homozygous for the A1 allele, 400 individuals homozygous for the A2 allele, and 500 heterozygous individuals. What are the genotype frequencies? What are the allele frequencies?arrow_forwardSelection may also act against heterozygotes. How do allele frequencies change if the two homozygotes have unequal fitness, but heterozgotes have a constant 50% reduced fitness? Simulate allele frequency changes with multiple values of p0 (between 0 and 1). can you explain what happens and whyarrow_forward
- Allelic diversity affects individual variability. What effect is a bottleneck likely to have on a population's ability to evolve?arrow_forwardRecall that the Hardy-Weinberg model makes the following assumptions: No mutations Extremely large population No gene flow No selection You score flower colour in a very large natural population where flower colour is a co-dominant trait where white and red are homozygotes (CWCW and CRCR) and pink are heterozygotes (CWCR). Taking your observed phenotypes and genotypes, you apply the Hardy-Weinberg principle and find an excess of homozygous individuals (that is, individuals with either white or red flowers). Give two plausible explanations for this excess of homozygotes in the natural population.arrow_forwardWhat evolutionary factors can cause allele frequencies to change and possibly lead to a genetic polymorphism? Discuss the relative importance of each type of process.arrow_forward
- Under the above conditions of reproductive discrimination against those with attached earlobes, if the population in this next generation is still 500,000 people, then the new genotypic frequencies will be: Homozygous dominants, unattached ear lobes: 0.34 Heterozygotes, unattached ear lobes: 0.48 Homozygous recessives, attached ear lobes: 0.18 What will be the allele frequencies for L and l in this generation? Did the frequency of the recessive allele (l), as compared to its frequency calculated in Part B, increase or decrease because of its deleterious effects on fitness? Does the possession of the recessive allele kill those who possess it? If those with attached ear lobes continue to be only half as successful in securing mates in each successive generation, what will happen to the frequency of the recessive allele in this population?arrow_forwardMark each statement as True/ False while describing frequency dependent, frequency independent and sexual selection. In negative frequency selection, rare phenotypes are selected against In positive frequency selection, the more common phenotype is selected for The long mane of the male lion which is not present in females is an example of sexual dimorphism An example of the handicap principle can be seen in the similar body forms of male and female birds such as the mourning dove The antlers seen in male antelope, caribou, and mountain goats are example of sexual dimorphismarrow_forwardGive one example of how allele frequencies change from one generation to the next due to mutation, migration, genetic drift, nonrandom mating, and 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:PEARSON
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
Anatomy & 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 & Company
Laboratory 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