(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 the following:

The Unifying Concept in Unifying Concept in BiologyBiology

Dr. Carol Eunmi LeeDr. Carol Eunmi Lee

University of Wisconsin, MadisonUniversity of Wisconsin, Madison

EVOLUTIOEVOLUTIONN

Theodosius Dobzhansky (1900-1975)

““Nothing in biology Nothing in biology

makes sense except in makes sense except in

the light of evolution”the light of evolution”

Reading

(1) Evolutionary Analysis

5th Edition, 2013Jon Herron & Scott Freeman

(2) Journal articles posted on Course Website

Course Website

https://mywebspace.wisc.edu/carollee/web/Lee/Evolution410.html

Background needed for this course

Some understanding of basic genetics (Hardy Weinberg Equilibrium, DNA, RNA, transcription, translation, allele, genotype)

1) Overview

2) What is Evolution?

3) Basic Concepts

3) Practical Applications

4) Example of Evolution in Action: Evolution of HIV

OUTLINE:

(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 OverviewCourse Overview:

Introduction What is Evolution? Practical Applications&Background History of Evolutionary Thought No Evolution Hardy Weinberg Equilibrium

Evolutionary Genetic DriftMechanisms Genetic Variation (Mutation,

Recombination)

Epigenetic VariationNatural Selection (including molecular and genome levels)

Macroevolution SpeciationHistory of Life on EarthTree of Life

Diversity Microbial EvolutionPlant EvolutionAnimal DiversityHuman Evolution

Structure of LecturesStructure of Lectures:

• 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 & ExamsGrading & Exams

300 (exams) + 60 (quizzes) + 90 pts (homework) + 50 pts (extra credit) = 500 points total

Q:Q: What is Evolution? What is Evolution?

Q:Q: How does Evolution Occur? How does Evolution Occur?

Q1: What is Evolution?

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

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)Blue Purple Red

 Generation 1: 250 500 250Generation 2: 200 600 200Generation 3: 100 800 100

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)

Q: What is Q: What is EvolutionEvolution?

Change in proportions of genetically different individuals at each generation

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)

Acts by removing individuals from the population, or by allowing some to leave more offspring

By population, we are referring to a group of interbreeding individuals and their offspring (in the case of sexual species)

Q3: How does Evolution Q3: How does Evolution Occur?Occur?

Q3: How does Evolution Q3: How does Evolution Occur?Occur?

***Through 5 Major Mechanisms:

Genetic Drift Mutation Heritable Epigenetic Modification Migration Natural Selection

(Think about what forces would change the allele frequencies in a population, or the heritable expression of those alleles)

i.e. what causes changes in i.e. what causes changes in the allelic composition in a the allelic composition in a population?population? Genetic Drift: totally random changes in allele frequency from generation to generation

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…

Migration: alleles moving from one population to another

Natural Selection: when some alleles favored over others due to an increase in fitness (not random); acts on genetic variation in the population

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

Evolutionary Concepts Evolutionary Concepts Permeate all Aspects Permeate all Aspects of Biologyof Biology

BiotechnologyBiotechnologyAgricultureAgriculture

MedicineMedicine

ConservationConservation

AgricultureAgriculture

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

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

HIV infects

macrophages,

T-cells

HIV: Fastest evolving organism on Earth

AIDS PandemicAIDS Pandemic

#people living with HIV

AIDS is among the most deadly epidemics in Human History (1981-2009: ~30 million deaths)

~34 million people living with AIDS (estimated 2010)

90 million deaths predicted by 2020

UNAIDS. 2008 Report on the Global AIDS Epidemic

(http://www.unaids.org/en/KnowledgeCentre/HIVData/GlobalReport/2008/)

A global view of HIV infection33 million people [30–36 million] living with HIV, 2007

ProblemProblem :: HIV has the fastest mutation rate of any virus or organism

observed to date

HIV evolves more rapidly than humans, and more quickly than the ability of humans to produce new drugs

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

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

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

EvolutionEvolutionPopulationPopulationGenetic DriftGenetic DriftNatural Natural SelectionSelectionMutationMutationGenetic Genetic VariationVariationAllele, Allele, GenotypeGenotypeHIVHIV

ConceptsConcepts