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BIO305: Genetics

Unit 9: Population and Evolutionary Genetics   This last unit will focus on the relationship between genetics, populations of organisms, and evolution. Our modern understanding of evolution would not be complete without understanding the genetics of evolutionary change. In this unit, we will look at some of the genetics-related topics associated with evolution. We will begin by discussing the genetics of a population of organisms. Because the frequencies of the traits in a population change with time to adapt to the environment, we know that the frequencies of the alleles producing these traits must also be changing. Accordingly, this unit focuses on studies of allele frequency change over time within a population. We will look at examples of human populations with unusually high frequency of a disease, and we will employ population genetics to explain why the particular disease is more common in the population.

Unit 9 Time Advisory
This unit should take you approximately 20 hours to complete:
 
☐    Subunit 9.1: 2.25 hours
 
☐    Subunit 9.2: 6 hours
☐    Introduction: 1.5 hours
 
☐    Subunit 9.2.1: 1 hour
 
☐    Subunit 9.2.2: 1 hour
 
☐    Subunit 9.2.3: 0.5 hours
 
☐    Subunit 9.2.4: 2 hours

☐    Subunit 9.3: 5 hours
☐    Subunit 9.3.1: 0.25 hours
 
☐    Subunit 9.3.2: 0.25 hours
 
☐    Subunit 9.3.3: 2.5 hours
 
☐    Subunit 9.3.4: 2 hours

☐    Subunit 9.4: 6 hours
☐    Introduction: 1 hour
 
☐    Subunit 9.4.1: 0.5 hours
 
☐    Subunit 9.4.2: 2.5 hours
 
☐    Subunit 9.4.3: 2 hours

☐    Subunit 9.5: 0.75 hours

Unit9 Learning Outcomes
Upon successful completion of this unit, you will be able to:
- compare and contrast as well as discuss allelic and gene frequencies; - discuss the consequence of genetic variation in populations; - explain the role of mutations in selection; - discuss how population genetics can explain the unusual frequency of diseases in certain populations; - identify the populations that are in equilibrium with the help of the Hardy-Weinberg equation; and - discuss the bottleneck, the founder effect, and nonrandom mating, and their effect on gene frequencies in a population.

9.1 Genetics of a Population   9.1.1 Hardy-Weinberg Equilibrium   - Reading: Massachusetts Institute of Technology: Professor Chris Kaiser’s “Lecture 25: Population Genetics: Hardy-Weinberg” Link: Massachusetts Institute of Technology: Professor Chris Kaiser’s “Lecture 25: Population Genetics: Hardy-Weinberg” (PDF)
 
Instructions: Select the PDF link for “Lecture 25: Population Genetics: Hardy-Weinberg,” and read these lecture notes. These lecture notes explain allele frequencies and genotype frequencies first. These notes also explain conditions when the frequencies of genotypes change in populations. This text is technical, so please plan to read it several times for a full understanding.
 
Reading these lecture notes should take approximately 30 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Reading: Dr. John W. Kimball’s Biology Pages: “The Hardy-Weinberg Equilibrium” Link: Dr. John W. Kimball’s Biology Pages: “The Hardy-Weinberg Equilibrium” (HTML)
     
    Introduction: Read this article. Note that the Hardy-Weinberg equation describes populations that are in equilibrium.
     
    Reading this article should take approximately 1 hour and 30 minutes.
     
    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.1.2 Phenotypic Frequency   - Reading: The Saylor Foundation’s “Phenotypic Frequency” Link: The Saylor Foundation’s “Phenotypic Frequency” (PDF)
 
Instructions: Read this article for an overview of phenotypic frequencies.
 
Reading this article should take less than 15 minutes.

9.2 Mutation and Selection   - Reading: Massachusetts Institute of Technology: Professor Chris Kaiser’s “Lecture 26: Population Genetics: Mutation and Selection” Link: Massachusetts Institute of Technology: Professor Chris Kaiser’s “Lecture 26: Population Genetics: Mutation and Selection” (PDF)
 
Instructions: Select the PDF link for “Lecture 26: Population Genetics: Mutation and Selection,” and read these lecture notes. These lecture notes discuss what can limit the frequency of disease causing recessive alleles in a population. These notes also explain that phenotypic advantage of sickle-cell anemia and cystic fibrosis alleles may contribute to the continuing presence of these alleles in human populations. This text is technical, so please plan to read it several times for a full understanding.
 
Reading these lecture notes should take approximately 1 hour and 30 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.2.1 Inbreeding   - Reading: Massachusetts Institute of Technology: Professor Chris Kaiser’s “Lecture 27: Population Genetics Inbreeding” Link: Massachusetts Institute of Technology: Professor Chris Kaiser’s “Lecture 27: Population Genetics: Inbreeding” (PDF)
 
Instructions: Select the PDF link for “Lecture 27: Population Genetics: Inbreeding,” and read these lecture notes. These lecture notes explain the consequence of consanguineous mating in a population. This text is technical, so please plan to read it several times for a full understanding.
 
Reading these lecture notes should take approximately 1 hour.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.2.2 Complex Traits   - Reading: Massachusetts Institute of Technology: Professor Gerry Fink’s “Lecture 31: Complex Traits” Link: Massachusetts Institute of Technology: Professor Gerry Fink’s “Lecture 31: Complex Traits” (PDF)
 
Instructions: Select the PDF link for “Lecture 31: Complex Traits,” and read these lecture notes. These lecture notes discuss examples of non-allelic heterogeneity in human populations. This text is technical, so please plan to read it several times for a full understanding.
 
Reading these lecture notes should take approximately 1 hour.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.2.3 Founder Effects   - Reading: University of California, Berkeley: Understanding Evolution “Bottlenecks and Founder Effects” Link: University of California, Berkeley: “Bottlenecks and Founder Effects” (HTML)
 
Instructions: Read this article. Once you have completed this reading, feel free to surf this website to read additional information that interests you.
 
Reading this article should take approximately 30 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.2.4 Nonrandom Mating   - Reading: Scott Freeman and Jon C. Herron’s Evolutionary Analysis: “Chapter 6: Mendelian Genetics in Populations II: Migration, Genetic Drift, and Non-Random Mating” Link: Scott Freeman and Jon C. Herron’s Evolutionary Analysis: “Chapter 6: Mendelian Genetics in Populations II: Migration, Genetic Drift, and Non-Random Mating” (HTML)
 
Instructions: Read this chapter for an overview of genetic drift, nonrandom mating, and other important concepts to population genetics.
 
Reading this chapter should take approximately 2 hours.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.3 Population Genetics and Human Disease   9.3.1 Ashkenazi Jews and Tay-Sachs Disease   - Reading: National Center for Biotechnology Information: “Tay-Sachs Disease” Link: National Center for Biotechnology Information: “Tay-Sachs Disease” (HTML)
 
Instructions: Read this article, which will give you a practical application for the genetics information you have learned so far.
 
Reading this article should take approximately 15 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.3.2 Amish Population and Ellis-van Creveld Syndrome   - Reading: National Center for Biotechnology Information: “Ellis-van Creveld Syndrome” Link: National Center for Biotechnology Information: “Ellis-van Creveld Syndrome” (HTML)
 
Instructions: Read this article about Ellis–van Creveld Syndrome.
 
Reading this article should take approximately 15 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.3.3 Microbial Antibiotic Resistance   - Reading: FDA Consumer: Dr. Ricki Lewis’s “The Rise of Antibiotic-Resistant Infections” Link: FDA Consumer: Dr. Ricki Lewis’s “The Rise of Antibiotic-Resistant Infections” (HTML)
 
Instructions: Read this article for an overview of antibiotic-resistant bacteria and how the existence of these bacterial strains is an example of evolution in action.
 
Reading this article should take approximately 2 hours.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Assessment: The Saylor Foundation’s “Antibiotic Resistance” Link: The Saylor Foundation’s “Antibiotic Resistance” (HTML)
     
    Instruction: Complete this multiple choice assessment. Clicking on an answer will bring you to another page: If your answer is correct, then it is acknowledged with a short explanation. If your answer is wrong, you will be taken to a tutorial page. Study the tutorial page carefully. At the end of the tutorial page, you will be prompted to return to the assessment to try it again. Note that antibiotic drugs attack both pathogenic and normal flora bacteria.
     
    Completing this assessment should take approximately 15 minutes.

  • Assessment: The Saylor Foundation’s “Phage Therapy” Link: The Saylor Foundation’s “Phage Therapy” (HTML)
     
    Instruction: Complete this multiple choice assessment. Clicking on an answer will bring you to another page: If your answer is correct, then it is acknowledged with a short explanation. If your answer is wrong, you will be taken to a tutorial page. Study the tutorial page carefully. At the end of the tutorial page, you will be prompted to return to the assessment to try it again.
     
    Completing this assessment should take approximately 15 minutes.

9.3.4 Sickle-Cell Anemia and Malaria Resistance   - Reading: Scitable by Nature Education: Dr. Abram Gabriel’s “Sickle-Cell Anemia: A Look at Global Haplotype Distribution Link: Scitable by Nature Education: Dr. Abram Gabriel’s “Sickle-Cell Anemia: A Look at Global Haplotype Distribution” (HTML)
 
Instructions: Read this article. Malaria resistance is the main reason why there are so many people with sickle-cell anemia. Researchers have found that carriers of the sickle-cell anemia gene are highly resistant to malaria. In countries where malaria is prevalent, carriers are likely to survive and are thus likely to have children with sickle-cell anemia.
 
Reading this article should take approximately 2 hours.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.4 Evolutionary Genetics   - Reading: Dr. John W. Kimball’s Biology Pages: “Evolution and Adaptation” Link: Dr. John W. Kimball’s Biology Pages: “Evolution and Adaptation” (HTML)
 
Instructions: Read this article. Note that phenotype and genotype frequencies change in populations over time unless each gene has only one and the same allele in all individuals of the population.
 
Reading this article should take approximately 1 hour.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.4.1 Molecular Clocks   - Reading: Dr. John W. Kimball’s Biology Pages: “Evolution of Homo sapiens Link: Dr. John W. Kimball’s Biology Pages: “Evolution of Homo sapiens (HTML)
 
Instructions: Read this article.
 
Reading this article should take approximately 30 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.4.2 Tree and Species Gene Tree   - Reading: Dr. John W. Kimball’s Biology Pages: “Taxonomy: Classifying Life” Link: Dr. John W. Kimball’s Biology Pages: “Taxonomy: Classifying Life” (HTML)
 
Instruction: Read this article. Be sure to follow the “Link to a phylogenetic tree of living hominoids based on DNA-DNA hybridization” hyperlink within the “DNA-DNA Hybridization” section. This link opens a webpage that explains the evolutionary relationship of hominoids. Note that evolution changes the genes not only across the phyla, but within a species as well.
 
Reading this article should take approximately 2 hour and 30 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.4.3 The Evolution of Development   - Lecture: New York University: Professor Stephen C. Stearns’ Principles of Evolution, Ecology, and Behavior: “Lecture 7 – The Importance of Development in Evolution” Link: New York University: Professor Stephen C. Stearns’ Principles of Evolution, Ecology, and Behavior: “Lecture 7 – The Importance of Development in Evolution” (Adobe Flash)
 
Instruction: Watch this lecture on evolution. This lecture is technical, so please plan to pause, take notes, and re-watch segments for a full understanding.
 
Watching this lecture and pausing to take notes should take approximately 2 hours.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.5 Genomics and the Future   - Lecture: New York University: Professor Mark Siegal’s Genomes and Diversity: “Lecture 25 – Genomics & the Future” Link: New York University: Professor Mark Siegal’s Genomes and Diversity: “Lecture 25 – Genomics & the Future” (Adobe Flash)
 
Instruction: Watch this lecture, which highlights how genomics will likely influence our life.
 
Watching this lecture and pausing to take notes should take approximately 15 minutes.
 
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Reading: The Saylor Foundation’s “The Future of Research” Link: The Saylor Foundation’s “The Future of Research” (PDF)
     
    Instructions: Read this article. The purpose of this subunit is to give you a new perspective on the future of genetic research while also helping you reflect on what you have learned in this course.
     
    Reading this article should take approximately 15 minutes.

  • Assessment: The Saylor Foundation’s “Unit 9 Assessment” Link: The Saylor Foundation’s “Unit 9 Assessment” (HTML)
     
    Instructions: Complete this multiple choice and true/false Unit 9 Assessment.
     
    Completing this assessment should take approximately 15 minutes.

Final Exam   - Final Exam: The Saylor Foundation’s “BIO305 Final Exam” Link: The Saylor Foundation’s “BIO305 Final Exam” (HTML)
 
Instructions: You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.