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(1) Name (2) Year (3) Major (4) Courses taken in Biology (4) Career goals (5) Email address (6) Why am I taking this class? On your Notecards please write.

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Presentation on theme: "(1) Name (2) Year (3) Major (4) Courses taken in Biology (4) Career goals (5) Email address (6) Why am I taking this class? On your Notecards please write."— Presentation transcript:

1 (1) Name (2) Year (3) Major (4) Courses taken in Biology (4) Career goals (5) address (6) Why am I taking this class? On your Notecards please write the following:

2 Unifying Concept in Biology The Unifying Concept in Biology Dr. Carol Eunmi Lee University of Wisconsin, Madison EVOLUTION EVOLUTION

3 Theodosius Dobzhansky ( ) “Nothing in biology makes sense except in the light of evolution”

4 Reading (1) Evolutionary Analysis 5 th Edition, 2013 Jon Herron & Scott Freeman (2) Journal articles posted on Course Website

5 Course Website n olution410.html

6 Background needed for this course n Some understanding of basic genetics (Hardy Weinberg Equilibrium, DNA, RNA, transcription, translation, allele, genotype)

7 1) Overview 2) What is Evolution? 3) Basic Concepts 3) Practical Applications 4) Example of Evolution in Action: Evolution of HIV OUTLINE:

8 (1) TODAY: What is Evolution? Practical Applications (2, 3) History of Evolutionary Thought (4) Hardy Weinberg Equilibrium (no evolution), Genetic Drift (5) EVOLUTIONARY MECHANISMS: Genetic Drift (6, 7) EVOLUTIONARY MECHANISMS: Genetic Variation (8) EVOLUTIONARY MECHANISMS: Epigenetic Inheritance (9,10) EVOLUTIONARY MECHANISMS: Natural Selection (11, 12) Molecular Evolution (13, 14) Genome Evolution (15, 16) Evolutionary Tradeoffs (17, 18) Speciation (19, 20) Earth History, History of Life on Earth (21, 22) Reconstructing the Tree of Life (23) Microbial Evolution (24) Plant Evolution (25, 26) Animal Diversity (27, 28) Human Evolution Course Overview Course Overview:

9 IntroductionWhat is Evolution? Practical Applications &BackgroundHistory of Evolutionary Thought No EvolutionHardy Weinberg Equilibrium EvolutionaryGenetic Drift MechanismsGenetic Variation ( Mutation, Recombination) Epigenetic Variation Natural Selection (including molecular and genome levels) MacroevolutionSpeciation History of Life on Earth Tree of Life DiversityMicrobial Evolution Plant Evolution Animal Diversity Human Evolution Structure of Lectures Structure of Lectures:

10 3 exams of equal weight, multiple choice: 100 points each = 300 pts total 3 quizzes: 20 points each = 60 pts total 3 homeworks: 30 points each = 90 pts total In-class extra credit, unannounced random dates: 50 pts Grading & Exams 300 (exams) + 60 (quizzes) + 90 pts (homework) + 50 pts (extra credit) = 500 points total

11 Q: What is Evolution? Q: How does Evolution Occur?

12 Q1: What is Evolution?

13 Q1: What is Evolution? (give the most comprehensive answer) (1)The increase in fitness over time due to natural selection, or adaptation. (2)The accumulation of mutations, which alter fitness over time. (3)The change in allele frequencies (or the heritable expression of those alleles) in a population across generations. (4)The progression into more complex forms of life

14 Q1: What is Evolution? (give the most comprehensive answer) The change in allele frequencies (or the heritable expression of those alleles) in a population across generations. (BB)(Bb)(bb) BluePurpleRed Generation 1: Generation 2: Generation 3: Although, even if allele frequencies in a population remain the same across generations, a population is evolving if it goes out of Hardy-Weinberg Equilibrium (more on this later)

15 Q: What is Evolution Q: What is Evolution? n Change in proportions of genetically different individuals at each generation n Leading to an average change in characteristics of populations over time  change in allele frequencies (genetic composition) or the heritable change in the expression of those alleles (epigenetic inheritance) n Acts by removing individuals from the population, or by allowing some to leave more offspring n By population, we are referring to a group of interbreeding individuals and their offspring (in the case of sexual species)

16 Q3: How does Evolution Occur?

17 *** Through 5 Major Mechanisms: n Genetic Drift n Mutation n Heritable Epigenetic Modificatio n n Migration n Natural Selection (Think about what forces would change the allele frequencies in a population, or the heritable expression of those alleles)

18 i.e. what causes changes in the allelic composition in a population? n Genetic Drift : totally random changes in allele frequency from generation to generation n Mutation : changes in the genetic code, such as errors in DNA replication, gene deletions or duplications, etc… Epigenetic Inheritance : heritable changes that are not due to changes in DNA sequence itself, but the expression of the DNA, such as changes in DNA methylation and histone modifications, etc… n Migration : alleles moving from one population to another n Natural Selection: when some alleles favored over others due to an increase in fitness (not random); acts on genetic variation in the population

19 Natural Selection Without genetic or epigenetic variation, Natural Selection cannot occur Mutation generates genetic variation Epigenetic modification changes expression of genes Genetic Drift reduces genetic variation Sources of Genetic Variation Natural Selection acts on genetic or epigenetic variation in a population

20 Evolutionary Concepts Permeate all Aspects of Biology BiotechnologyAgricultureMedicineConservation

21 Agriculture n Most of your food is a product of intense artificial selection, or human induced evolution

22 Evolution of a Pathogen as an Example: I will now use an infectious disease to illustrate basic evolutionary concepts. The following example illustrates several evolutionary mechanisms I will explain these concepts in more detail over the next few lectures

23 HIV infects macrophages, T-cells HIV : Fastest evolving organism on Earth

24 AIDS Pandemic #people living with HIV n AIDS is among the most deadly epidemics in Human History ( : ~30 million deaths) n ~34 million people living with AIDS (estimated 2010) 90 million deaths predicted by 2020 UNAIDS Report on the Global AIDS Epidemic ( dgeCentre/HIVData/GlobalRepor t/2008/)

25 A global view of HIV infection 33 million people [30–36 million] living with HIV, 2007

26 Problem : n HIV has the fastest mutation rate of any virus or organism observed to date n HIV evolves more rapidly than humans, and more quickly than the ability of humans to produce new drugs n Implications: AIDS vaccines are unlikely to work on all strains of the virus… …and unlikely to work on a given strain in the long run n Our understanding of how to combat viruses had in general been poor, and the recent intensive research on HIV has greatly enhanced our understanding of how to combat viruses in general

27 Questions: (1) What is Evolution? (2) How does evolution operate? What are the main Evolutionary Mechanisms? (3) Discuss how an understanding of evolution impacts practices in Agriculture, Medicine, and Conservation (4) For example, discuss how different evolutionary mechanisms impact the evolution of HIV, the virus that causes AIDS

28 EvolutionPopulation Genetic Drift Natural Selection Mutation Genetic Variation Allele, Genotype HIV Concepts

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