Population Genetics I. Bio

Size: px
Start display at page:

Download "Population Genetics I. Bio"

Transcription

1 Population Genetics I. Bio Don Conrad

2 Why study population genetics? Functional Inference Demographic inference: History of mankind is written in our DNA. We can learn about our species population size changes, migrations, etc. Complex disease: What approaches for analysis make sense? Molecular biology: Measure rates of biological processes like mutation and recombination, learn about gene regulation, speciation Sequencing era. Framework for understanding these sequences. You will have your own genome sequence

3 Outline for Part I and Part II Theory Hardy-Weinberg Forward Models: Wright Fisher Model Backward Models: Coalescent Data Mutation, mutation rates Global diversity, serial bottleneck model Recombination, LD blocks, recombination hotspots Natural Selection

4 Hardy-Weinberg What is the fate of a neutral genetic variant at a biallelic locus in an infinite population? Udney Yule: individuals with dominant traits will increase in the population over time Hardy: Yule is wrong, and that expected genotype frequencies are simply the product of underlying allele frequencies assuming independence

5 Hardy s Argument: Generation 1 Males are 100% AA Females are 100% aa What will be the genotype composition of generation 2? Males A (100%) a (0%) Females A (0%) AA (0%) Aa (0%) a (100%) Aa (100%) aa (0%)

6 Hardy s Argument: Generation 2 Now males are 100% Aa and females are 100% Aa What will Gen 3 look like? Males A (50%) a (50%) Females A (50%) AA (25%) Aa (25%) a (50%) Aa (25%) aa (25%) Freq of a = p = ( 2*25+1*50 ) / 200 = 0.5 Freq of A = q = 1-p = 0.5 Allele frequencies are the same in Gen 3 as in Gen 2 So we have reached an equilibrium

7 Hardy s Argument: Generation 3 Males A (50%) a (50%) Females A (50%) AA (25%) Aa (25%) a (50%) Aa (25%) aa (25%) p = ( 2*25+1*50 ) / 200 = 0.5 q = 1-p = 0.5 The famous equation describes genotype frequencies as a function of allele frequencies at equilibrium: p 2 + 2pq + q 2 = 1

8 Gcbias.org

9 Modern Synthesis Reconciliation of Mendelian genetics with observations of the Biometrists Reconciliation of Mendelian genetics with Darwinian evolution R.A. Fisher Sewall Wright J.B.S Haldane

10 Wright-Fisher Model Assumptions: Two allele system N diploid individuals in each generation 2N gametes Random mating, no selection Discrete generations Generation t A a Gamete pool A a a A A A a a A a t + 1

11 Let s play a round of this game

12 The game is faster by computer I = 400 A = 200 R = 100 G = 100 I = Number of Generations A = Population size (gametes) G = Count of the G allele R = Count of the R allele

13 I = 400 A = 200 R = 100 G = 100

14 I = 400 A = 200 R = 100 G = 100

15 Let s investigate this phenomenon Change Population Size Change allele frequencies

16 I = 40 A = 20 R = 10 G = 10

17 I = 40 A = 20 R = 10 G = 10

18 I = 1000 A = 2000 R = 1000 G = 1000

19 I = 1000 A = 2000 R = 1000 G = 1000

20 I = 400 A = 200 R = 150 G = 50

21 I = 400 A = 200 R = 150 G = 50

22 I = 400 A = 200 R = 150 G = 50

23 Each generation, the new population is made by sampling with replacement from the previous generation A a a A A A a a A a AA Aa aa Let: P t = freq (A) among gametes P t+1 =. In the next generation n t+1 = count of (A).. Aa Then: n t+1 ~ Binomial (P t, 2N) Pr( n t+1 = m)! = # 2 N " m $ & % p 1 pt tm ( ) 2 N m E( p t+1 ) = P t Var( p t+1 ) = p t (1-p t ) 2N Implications: sampling variance ( genetic drift ) is dependent on population size. Allele frequency is a random sequence of numbers: p 1, p 2, p 3, Eventually p = 1 or p = 0. Stay fixed until new mutation.

24 Thinking like a (classical) population geneticist Simulations versus analysis Classical population geneticists tried to prove features of the Mendelian system Lets explore this hypothesis: One allele must always win.

25 The Decay of Heterozygosity Define G t, the homozygosity at generation t. = probability of randomly picking two chromosomes from population and they are the same allele Then the heterozygosity H t = 1- G t. What happens to G t over time, under the assumptions of Wright-Fisher?

26 What is G 0 A A B BB B B B 1. Pick A then A = number of A s / 2N * number A s-1 / (2N-1) Generation 0 2. Pick B then B = number of B s / 2N) * (number B s-1) / (2N-1)

27 What is G 1? Probability = 1/2N Generation 0 Generation 1 Probability (1-1/2N)*G 0 Generation 0 Generation 1

28 Proof of decay of heterozygosity

29 What is the half life of H? H 0 /2 = H 0 (1-1/2N) t t = 2Nln2 N = 10^4, t = 1.1e5 generations

30 What does this mean? In a large population, eventually, every allele will have descended from a single allele in the founding population! All but 1 allele will have died off.

31 -Genealogical Analysis of all 131K Icelanders born after 1972

32 Drift versus Darwin How can we add selection to our game? We need to account for dominant and recessive alleles!

33 The Wright Fisher Game v0.2 Define relative fitness for each possible individual Fitness RR = 1 Fitness RG = 1.1 Fitness GG = 2 Modify rules. Pick an individual with probability proportional to the fitness of her genotype. A given GG individual is twice as likely to be picked. Now choose one chromosome and put into the next generation.

34 What relative fitness should we select? Conserved elements <0.01% increase in fitness

35 Drift versus Darwin I = 100 A = 100 R = 99 G = 1 fg = 2*fR

36 I = 100 A = 100 R = 99 G = 1 fg = 3*fR

37 I = 100 A = 100 R = 99 G = 1 fg = 3*fR

38 I = 100 A = 100 R = 99 G = 1 fg = 3*fR

39 I = 100 A = 2000 R = 1999 G = 1 fg = 3*fR

40 Some startling results! Survival of the fittest luckiest. Sometimes drift can overcome selection. Depends on allele frequency, population size. Most new advantageous mutations are not fixed!

41 Mutation Infinite alleles model Assumptions

42 I = 5000 U = Start as Homozygous At allele A U=mutation rate

43 Summary thus far Chance can play a large role in determining which polymorphisms are fixed in a population. These findings are/were not obvious. Amount of a variation at a locus, and the fate of individual alleles, is the product of Mutation-selection-drift balance

44 Recursion equations Genotype Total AA Aa aa Freq in generation t q 2 2pq p 2 1 = q 2 + 2pq + p 2 Fitness w 11 w 12 w 22 Freq (after selection) q 2 w 11 2pqw 12 p 2 w 22 ŵ = q 2 w pqw 12 +p 2 w 22 p t+1 = p 2 w 22 +pqw 12 ŵ q t+1 = q 2 w 11 +pqw 12 ŵ Recursion equations for analysis of selection Assumptions in this example: no drift or mutation, discrete generations, random mating

45 Evolutionary dynamics in a simplex for a biallelic locus aa AA Analysis of recursion equations, and later, differential equations, was the central tool for classical popgen Aa 2010 by National Academy of Sciences Modified from Gokhale C S, Traulsen A PNAS 2010;107:

46 Dynamics:Topics covered Selection (additive, balancing, frequency-dependent) Altruism, kin selection Structural variation (inversions) Multiple loci (recombination, epistatic selection) Population structure (island model, stepping stone model, isolation by distance, metapopulation models) Assortative mating Sex-specific effects (migration, selection) Variable environments, etc

47 Sampling with Replacement Past Some alleles pass on no copies to the next generation, while some pass on more than one. Present

48 The Coalescent Process ACTT T G C G ACGT ACGT ACTT ACTT AGTT Backward in time process Discovered by JFC Kingman, F. Tajima, R. R. Hudson c DNA sequence diversity is shaped by genealogical history Genealogies are unobserved but can be estimated Conceptual framework for population genetic inference: mutation, recombination, demographic history

Processes of Evolution

Processes of Evolution 15 Processes of Evolution Forces of Evolution Concept 15.4 Selection Can Be Stabilizing, Directional, or Disruptive Natural selection can act on quantitative traits in three ways: Stabilizing selection

More information

Problems for 3505 (2011)

Problems for 3505 (2011) Problems for 505 (2011) 1. In the simplex of genotype distributions x + y + z = 1, for two alleles, the Hardy- Weinberg distributions x = p 2, y = 2pq, z = q 2 (p + q = 1) are characterized by y 2 = 4xz.

More information

Population Genetics. with implications for Linkage Disequilibrium. Chiara Sabatti, Human Genetics 6357a Gonda

Population Genetics. with implications for Linkage Disequilibrium. Chiara Sabatti, Human Genetics 6357a Gonda 1 Population Genetics with implications for Linkage Disequilibrium Chiara Sabatti, Human Genetics 6357a Gonda csabatti@mednet.ucla.edu 2 Hardy-Weinberg Hypotheses: infinite populations; no inbreeding;

More information

Introduction to population genetics & evolution

Introduction to population genetics & evolution Introduction to population genetics & evolution Course Organization Exam dates: Feb 19 March 1st Has everybody registered? Did you get the email with the exam schedule Summer seminar: Hot topics in Bioinformatics

More information

The Wright-Fisher Model and Genetic Drift

The Wright-Fisher Model and Genetic Drift The Wright-Fisher Model and Genetic Drift January 22, 2015 1 1 Hardy-Weinberg Equilibrium Our goal is to understand the dynamics of allele and genotype frequencies in an infinite, randomlymating population

More information

How robust are the predictions of the W-F Model?

How robust are the predictions of the W-F Model? How robust are the predictions of the W-F Model? As simplistic as the Wright-Fisher model may be, it accurately describes the behavior of many other models incorporating additional complexity. Many population

More information

Outline of lectures 3-6

Outline of lectures 3-6 GENOME 453 J. Felsenstein Evolutionary Genetics Autumn, 007 Population genetics Outline of lectures 3-6 1. We want to know what theory says about the reproduction of genotypes in a population. This results

More information

Lecture 1 Hardy-Weinberg equilibrium and key forces affecting gene frequency

Lecture 1 Hardy-Weinberg equilibrium and key forces affecting gene frequency Lecture 1 Hardy-Weinberg equilibrium and key forces affecting gene frequency Bruce Walsh lecture notes Introduction to Quantitative Genetics SISG, Seattle 16 18 July 2018 1 Outline Genetics of complex

More information

NOTES CH 17 Evolution of. Populations

NOTES CH 17 Evolution of. Populations NOTES CH 17 Evolution of Vocabulary Fitness Genetic Drift Punctuated Equilibrium Gene flow Adaptive radiation Divergent evolution Convergent evolution Gradualism Populations 17.1 Genes & Variation Darwin

More information

Outline of lectures 3-6

Outline of lectures 3-6 GENOME 453 J. Felsenstein Evolutionary Genetics Autumn, 009 Population genetics Outline of lectures 3-6 1. We want to know what theory says about the reproduction of genotypes in a population. This results

More information

Q1) Explain how background selection and genetic hitchhiking could explain the positive correlation between genetic diversity and recombination rate.

Q1) Explain how background selection and genetic hitchhiking could explain the positive correlation between genetic diversity and recombination rate. OEB 242 Exam Practice Problems Answer Key Q1) Explain how background selection and genetic hitchhiking could explain the positive correlation between genetic diversity and recombination rate. First, recall

More information

Mechanisms of Evolution

Mechanisms of Evolution Mechanisms of Evolution 36-149 The Tree of Life Christopher R. Genovese Department of Statistics 132H Baker Hall x8-7836 http://www.stat.cmu.edu/ ~ genovese/. Plan 1. Two More Generations 2. The Hardy-Weinberg

More information

8. Genetic Diversity

8. Genetic Diversity 8. Genetic Diversity Many ways to measure the diversity of a population: For any measure of diversity, we expect an estimate to be: when only one kind of object is present; low when >1 kind of objects

More information

Solutions to Even-Numbered Exercises to accompany An Introduction to Population Genetics: Theory and Applications Rasmus Nielsen Montgomery Slatkin

Solutions to Even-Numbered Exercises to accompany An Introduction to Population Genetics: Theory and Applications Rasmus Nielsen Montgomery Slatkin Solutions to Even-Numbered Exercises to accompany An Introduction to Population Genetics: Theory and Applications Rasmus Nielsen Montgomery Slatkin CHAPTER 1 1.2 The expected homozygosity, given allele

More information

Homework Assignment, Evolutionary Systems Biology, Spring Homework Part I: Phylogenetics:

Homework Assignment, Evolutionary Systems Biology, Spring Homework Part I: Phylogenetics: Homework Assignment, Evolutionary Systems Biology, Spring 2009. Homework Part I: Phylogenetics: Introduction. The objective of this assignment is to understand the basics of phylogenetic relationships

More information

The Mechanisms of Evolution

The Mechanisms of Evolution The Mechanisms of Evolution Figure.1 Darwin and the Voyage of the Beagle (Part 1) 2/8/2006 Dr. Michod Intro Biology 182 (PP 3) 4 The Mechanisms of Evolution Charles Darwin s Theory of Evolution Genetic

More information

Introduction to Natural Selection. Ryan Hernandez Tim O Connor

Introduction to Natural Selection. Ryan Hernandez Tim O Connor Introduction to Natural Selection Ryan Hernandez Tim O Connor 1 Goals Learn about the population genetics of natural selection How to write a simple simulation with natural selection 2 Basic Biology genome

More information

A. Correct! Genetically a female is XX, and has 22 pairs of autosomes.

A. Correct! Genetically a female is XX, and has 22 pairs of autosomes. MCAT Biology - Problem Drill 08: Meiosis and Genetic Variability Question No. 1 of 10 1. A human female has pairs of autosomes and her sex chromosomes are. Question #01 (A) 22, XX. (B) 23, X. (C) 23, XX.

More information

LECTURE # How does one test whether a population is in the HW equilibrium? (i) try the following example: Genotype Observed AA 50 Aa 0 aa 50

LECTURE # How does one test whether a population is in the HW equilibrium? (i) try the following example: Genotype Observed AA 50 Aa 0 aa 50 LECTURE #10 A. The Hardy-Weinberg Equilibrium 1. From the definitions of p and q, and of p 2, 2pq, and q 2, an equilibrium is indicated (p + q) 2 = p 2 + 2pq + q 2 : if p and q remain constant, and if

More information

Microevolution Changing Allele Frequencies

Microevolution Changing Allele Frequencies Microevolution Changing Allele Frequencies Evolution Evolution is defined as a change in the inherited characteristics of biological populations over successive generations. Microevolution involves the

More information

Population Genetics & Evolution

Population Genetics & Evolution The Theory of Evolution Mechanisms of Evolution Notes Pt. 4 Population Genetics & Evolution IMPORTANT TO REMEMBER: Populations, not individuals, evolve. Population = a group of individuals of the same

More information

Gene Genealogies Coalescence Theory. Annabelle Haudry Glasgow, July 2009

Gene Genealogies Coalescence Theory. Annabelle Haudry Glasgow, July 2009 Gene Genealogies Coalescence Theory Annabelle Haudry Glasgow, July 2009 What could tell a gene genealogy? How much diversity in the population? Has the demographic size of the population changed? How?

More information

AEC 550 Conservation Genetics Lecture #2 Probability, Random mating, HW Expectations, & Genetic Diversity,

AEC 550 Conservation Genetics Lecture #2 Probability, Random mating, HW Expectations, & Genetic Diversity, AEC 550 Conservation Genetics Lecture #2 Probability, Random mating, HW Expectations, & Genetic Diversity, Today: Review Probability in Populatin Genetics Review basic statistics Population Definition

More information

EVOLUTION UNIT. 3. Unlike his predecessors, Darwin proposed a mechanism by which evolution could occur called.

EVOLUTION UNIT. 3. Unlike his predecessors, Darwin proposed a mechanism by which evolution could occur called. EVOLUTION UNIT Name Read Chapters 1.3, 20, 21, 22, 24.1 and 35.9 and complete the following. Chapter 1.3 Review from The Science of Biology 1. Discuss the influences, experiences and observations that

More information

Evolutionary Genetics Midterm 2008

Evolutionary Genetics Midterm 2008 Student # Signature The Rules: (1) Before you start, make sure you ve got all six pages of the exam, and write your name legibly on each page. P1: /10 P2: /10 P3: /12 P4: /18 P5: /23 P6: /12 TOT: /85 (2)

More information

Study of similarities and differences in body plans of major groups Puzzling patterns:

Study of similarities and differences in body plans of major groups Puzzling patterns: Processes of Evolution Evolutionary Theories Widely used to interpret the past and present, and even to predict the future Reveal connections between the geological record, fossil record, and organismal

More information

Population Structure

Population Structure Ch 4: Population Subdivision Population Structure v most natural populations exist across a landscape (or seascape) that is more or less divided into areas of suitable habitat v to the extent that populations

More information

Genetics and Natural Selection

Genetics and Natural Selection Genetics and Natural Selection Darwin did not have an understanding of the mechanisms of inheritance and thus did not understand how natural selection would alter the patterns of inheritance in a population.

More information

Life Cycles, Meiosis and Genetic Variability24/02/2015 2:26 PM

Life Cycles, Meiosis and Genetic Variability24/02/2015 2:26 PM Life Cycles, Meiosis and Genetic Variability iclicker: 1. A chromosome just before mitosis contains two double stranded DNA molecules. 2. This replicated chromosome contains DNA from only one of your parents

More information

Mutation, Selection, Gene Flow, Genetic Drift, and Nonrandom Mating Results in Evolution

Mutation, Selection, Gene Flow, Genetic Drift, and Nonrandom Mating Results in Evolution Mutation, Selection, Gene Flow, Genetic Drift, and Nonrandom Mating Results in Evolution 15.2 Intro In biology, evolution refers specifically to changes in the genetic makeup of populations over time.

More information

Mathematical modelling of Population Genetics: Daniel Bichener

Mathematical modelling of Population Genetics: Daniel Bichener Mathematical modelling of Population Genetics: Daniel Bichener Contents 1 Introduction 3 2 Haploid Genetics 4 2.1 Allele Frequencies......................... 4 2.2 Natural Selection in Discrete Time...............

More information

UNIT 8 BIOLOGY: Meiosis and Heredity Page 148

UNIT 8 BIOLOGY: Meiosis and Heredity Page 148 UNIT 8 BIOLOGY: Meiosis and Heredity Page 148 CP: CHAPTER 6, Sections 1-6; CHAPTER 7, Sections 1-4; HN: CHAPTER 11, Section 1-5 Standard B-4: The student will demonstrate an understanding of the molecular

More information

Notes for MCTP Week 2, 2014

Notes for MCTP Week 2, 2014 Notes for MCTP Week 2, 2014 Lecture 1: Biological background Evolutionary biology and population genetics are highly interdisciplinary areas of research, with many contributions being made from mathematics,

More information

19. Genetic Drift. The biological context. There are four basic consequences of genetic drift:

19. Genetic Drift. The biological context. There are four basic consequences of genetic drift: 9. Genetic Drift Genetic drift is the alteration of gene frequencies due to sampling variation from one generation to the next. It operates to some degree in all finite populations, but can be significant

More information

Effective population size and patterns of molecular evolution and variation

Effective population size and patterns of molecular evolution and variation FunDamental concepts in genetics Effective population size and patterns of molecular evolution and variation Brian Charlesworth Abstract The effective size of a population,, determines the rate of change

More information

Genetic Variation in Finite Populations

Genetic Variation in Finite Populations Genetic Variation in Finite Populations The amount of genetic variation found in a population is influenced by two opposing forces: mutation and genetic drift. 1 Mutation tends to increase variation. 2

More information

Big Idea #1: The process of evolution drives the diversity and unity of life

Big Idea #1: The process of evolution drives the diversity and unity of life BIG IDEA! Big Idea #1: The process of evolution drives the diversity and unity of life Key Terms for this section: emigration phenotype adaptation evolution phylogenetic tree adaptive radiation fertility

More information

Microevolution 2 mutation & migration

Microevolution 2 mutation & migration Microevolution 2 mutation & migration Assumptions of Hardy-Weinberg equilibrium 1. Mating is random 2. Population size is infinite (i.e., no genetic drift) 3. No migration 4. No mutation 5. No selection

More information

Neutral Theory of Molecular Evolution

Neutral Theory of Molecular Evolution Neutral Theory of Molecular Evolution Kimura Nature (968) 7:64-66 King and Jukes Science (969) 64:788-798 (Non-Darwinian Evolution) Neutral Theory of Molecular Evolution Describes the source of variation

More information

Chapter 17: Population Genetics and Speciation

Chapter 17: Population Genetics and Speciation Chapter 17: Population Genetics and Speciation Section 1: Genetic Variation Population Genetics: Normal Distribution: a line graph showing the general trends in a set of data of which most values are near

More information

EXERCISES FOR CHAPTER 3. Exercise 3.2. Why is the random mating theorem so important?

EXERCISES FOR CHAPTER 3. Exercise 3.2. Why is the random mating theorem so important? Statistical Genetics Agronomy 65 W. E. Nyquist March 004 EXERCISES FOR CHAPTER 3 Exercise 3.. a. Define random mating. b. Discuss what random mating as defined in (a) above means in a single infinite population

More information

URN MODELS: the Ewens Sampling Lemma

URN MODELS: the Ewens Sampling Lemma Department of Computer Science Brown University, Providence sorin@cs.brown.edu October 3, 2014 1 2 3 4 Mutation Mutation: typical values for parameters Equilibrium Probability of fixation 5 6 Ewens Sampling

More information

Population genetics snippets for genepop

Population genetics snippets for genepop Population genetics snippets for genepop Peter Beerli August 0, 205 Contents 0.Basics 0.2Exact test 2 0.Fixation indices 4 0.4Isolation by Distance 5 0.5Further Reading 8 0.6References 8 0.7Disclaimer

More information

Evolution and the Genetics of Structured populations. Charles Goodnight Department of Biology University of Vermont

Evolution and the Genetics of Structured populations. Charles Goodnight Department of Biology University of Vermont Evolution and the Genetics of Structured populations Charles Goodnight Department of Biology University of Vermont Outline What is Evolution Evolution and the Reductionist Approach Fisher/Wright Controversy

More information

5/31/2012. Speciation and macroevolution - Chapter

5/31/2012. Speciation and macroevolution - Chapter Speciation and macroevolution - Chapter Objectives: - Review meiosis -Species -Repro. Isolating mechanisms - Speciation -Is evolution always slow -Extinction How Are Populations, Genes, And Evolution Related?

More information

overproduction variation adaptation Natural Selection speciation adaptation Natural Selection speciation

overproduction variation adaptation Natural Selection speciation adaptation Natural Selection speciation Evolution Evolution Chapters 22-25 Changes in populations, species, or groups of species. Variances of the frequency of heritable traits that appear from one generation to the next. 2 Areas of Evolutionary

More information

Notes on Population Genetics

Notes on Population Genetics Notes on Population Genetics Graham Coop 1 1 Department of Evolution and Ecology & Center for Population Biology, University of California, Davis. To whom correspondence should be addressed: gmcoop@ucdavis.edu

More information

Outline of lectures 3-6

Outline of lectures 3-6 GENOME 453 J. Felsenstein Evolutionary Genetics Autumn, 013 Population genetics Outline of lectures 3-6 1. We ant to kno hat theory says about the reproduction of genotypes in a population. This results

More information

Chapter 16. Table of Contents. Section 1 Genetic Equilibrium. Section 2 Disruption of Genetic Equilibrium. Section 3 Formation of Species

Chapter 16. Table of Contents. Section 1 Genetic Equilibrium. Section 2 Disruption of Genetic Equilibrium. Section 3 Formation of Species Population Genetics and Speciation Table of Contents Section 1 Genetic Equilibrium Section 2 Disruption of Genetic Equilibrium Section 3 Formation of Species Section 1 Genetic Equilibrium Objectives Identify

More information

The neutral theory of molecular evolution

The neutral theory of molecular evolution The neutral theory of molecular evolution Introduction I didn t make a big deal of it in what we just went over, but in deriving the Jukes-Cantor equation I used the phrase substitution rate instead of

More information

BIOL Evolution. Lecture 9

BIOL Evolution. Lecture 9 BIOL 432 - Evolution Lecture 9 J Krause et al. Nature 000, 1-4 (2010) doi:10.1038/nature08976 Selection http://www.youtube.com/watch?v=a38k mj0amhc&feature=playlist&p=61e033 F110013706&index=0&playnext=1

More information

POPULATIONS. p t+1 = p t (1-u) + q t (v) p t+1 = p t (1-u) + (1-p t ) (v) Phenotypic Evolution: Process HOW DOES MUTATION CHANGE ALLELE FREQUENCIES?

POPULATIONS. p t+1 = p t (1-u) + q t (v) p t+1 = p t (1-u) + (1-p t ) (v) Phenotypic Evolution: Process HOW DOES MUTATION CHANGE ALLELE FREQUENCIES? Phenotypic Evolution: Process MUTATION SELECTION + POPULATIONS +/ MIGRATION DRIFT HOW DOES MUTATION CHANGE ALLELE FREQUENCIES? Assume: a single autosomal locus with 2 alleles. Frequency (A) = p Frequency

More information

The Genetics of Natural Selection

The Genetics of Natural Selection The Genetics of Natural Selection Introduction So far in this course, we ve focused on describing the pattern of variation within and among populations. We ve talked about inbreeding, which causes genotype

More information

Name Class Date. KEY CONCEPT Gametes have half the number of chromosomes that body cells have.

Name Class Date. KEY CONCEPT Gametes have half the number of chromosomes that body cells have. Section 1: Chromosomes and Meiosis KEY CONCEPT Gametes have half the number of chromosomes that body cells have. VOCABULARY somatic cell autosome fertilization gamete sex chromosome diploid homologous

More information

Biology 213 Summer 2004 Midterm III Choose the most correct answer and mark it on the scantron sheet. (2 pts each)

Biology 213 Summer 2004 Midterm III Choose the most correct answer and mark it on the scantron sheet. (2 pts each) Biology 213 Summer 2004 Midterm III Choose the most correct answer and mark it on the scantron sheet. (2 pts each) 1. Evolution is a. a change in allele frequency in a population b. occurred in the past

More information

Microevolution (Ch 16) Test Bank

Microevolution (Ch 16) Test Bank Microevolution (Ch 16) Test Bank Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Which of the following statements describes what all members

More information

Mathematical models in population genetics II

Mathematical models in population genetics II Mathematical models in population genetics II Anand Bhaskar Evolutionary Biology and Theory of Computing Bootcamp January 1, 014 Quick recap Large discrete-time randomly mating Wright-Fisher population

More information

Question: If mating occurs at random in the population, what will the frequencies of A 1 and A 2 be in the next generation?

Question: If mating occurs at random in the population, what will the frequencies of A 1 and A 2 be in the next generation? October 12, 2009 Bioe 109 Fall 2009 Lecture 8 Microevolution 1 - selection The Hardy-Weinberg-Castle Equilibrium - consider a single locus with two alleles A 1 and A 2. - three genotypes are thus possible:

More information

Outline for today s lecture (Ch. 14, Part I)

Outline for today s lecture (Ch. 14, Part I) Outline for today s lecture (Ch. 14, Part I) Ploidy vs. DNA content The basis of heredity ca. 1850s Mendel s Experiments and Theory Law of Segregation Law of Independent Assortment Introduction to Probability

More information

Demography April 10, 2015

Demography April 10, 2015 Demography April 0, 205 Effective Population Size The Wright-Fisher model makes a number of strong assumptions which are clearly violated in many populations. For example, it is unlikely that any population

More information

List the five conditions that can disturb genetic equilibrium in a population.(10)

List the five conditions that can disturb genetic equilibrium in a population.(10) List the five conditions that can disturb genetic equilibrium in a population.(10) The five conditions are non-random mating, small population size, immigration or emigration, mutations, and natural selection.

More information

Mathematical Population Genetics II

Mathematical Population Genetics II Mathematical Population Genetics II Lecture Notes Joachim Hermisson March 20, 2015 University of Vienna Mathematics Department Oskar-Morgenstern-Platz 1 1090 Vienna, Austria Copyright (c) 2013/14/15 Joachim

More information

Gene Pool The combined genetic material for all the members of a population. (all the genes in a population)

Gene Pool The combined genetic material for all the members of a population. (all the genes in a population) POPULATION GENETICS NOTES Gene Pool The combined genetic material for all the members of a population. (all the genes in a population) Allele Frequency The number of times a specific allele occurs in a

More information

Darwinian Selection. Chapter 6 Natural Selection Basics 3/25/13. v evolution vs. natural selection? v evolution. v natural selection

Darwinian Selection. Chapter 6 Natural Selection Basics 3/25/13. v evolution vs. natural selection? v evolution. v natural selection Chapter 6 Natural Selection Basics Natural Selection Haploid Diploid, Sexual Results for a Diallelic Locus Fisher s Fundamental Theorem Darwinian Selection v evolution vs. natural selection? v evolution

More information

Q Expected Coverage Achievement Merit Excellence. Punnett square completed with correct gametes and F2.

Q Expected Coverage Achievement Merit Excellence. Punnett square completed with correct gametes and F2. NCEA Level 2 Biology (91157) 2018 page 1 of 6 Assessment Schedule 2018 Biology: Demonstrate understanding of genetic variation and change (91157) Evidence Q Expected Coverage Achievement Merit Excellence

More information

Enduring Understanding: Change in the genetic makeup of a population over time is evolution Pearson Education, Inc.

Enduring Understanding: Change in the genetic makeup of a population over time is evolution Pearson Education, Inc. Enduring Understanding: Change in the genetic makeup of a population over time is evolution. Objective: You will be able to identify the key concepts of evolution theory Do Now: Read the enduring understanding

More information

Introduction to Advanced Population Genetics

Introduction to Advanced Population Genetics Introduction to Advanced Population Genetics Learning Objectives Describe the basic model of human evolutionary history Describe the key evolutionary forces How demography can influence the site frequency

More information

Reproduction and Evolution Practice Exam

Reproduction and Evolution Practice Exam Reproduction and Evolution Practice Exam Topics: Genetic concepts from the lecture notes including; o Mitosis and Meiosis, Homologous Chromosomes, Haploid vs Diploid cells Reproductive Strategies Heaviest

More information

6 Introduction to Population Genetics

6 Introduction to Population Genetics Grundlagen der Bioinformatik, SoSe 14, D. Huson, May 18, 2014 67 6 Introduction to Population Genetics This chapter is based on: J. Hein, M.H. Schierup and C. Wuif, Gene genealogies, variation and evolution,

More information

The theory of evolution continues to be refined as scientists learn new information.

The theory of evolution continues to be refined as scientists learn new information. Section 3: The theory of evolution continues to be refined as scientists learn new information. K What I Know W What I Want to Find Out L What I Learned Essential Questions What are the conditions of the

More information

Week 7.2 Ch 4 Microevolutionary Proceses

Week 7.2 Ch 4 Microevolutionary Proceses Week 7.2 Ch 4 Microevolutionary Proceses 1 Mendelian Traits vs Polygenic Traits Mendelian -discrete -single gene determines effect -rarely influenced by environment Polygenic: -continuous -multiple genes

More information

Lecture 14 Chapter 11 Biology 5865 Conservation Biology. Problems of Small Populations Population Viability Analysis

Lecture 14 Chapter 11 Biology 5865 Conservation Biology. Problems of Small Populations Population Viability Analysis Lecture 14 Chapter 11 Biology 5865 Conservation Biology Problems of Small Populations Population Viability Analysis Minimum Viable Population (MVP) Schaffer (1981) MVP- A minimum viable population for

More information

Parts 2. Modeling chromosome segregation

Parts 2. Modeling chromosome segregation Genome 371, Autumn 2018 Quiz Section 2 Meiosis Goals: To increase your familiarity with the molecular control of meiosis, outcomes of meiosis, and the important role of crossing over in generating genetic

More information

Parts 2. Modeling chromosome segregation

Parts 2. Modeling chromosome segregation Genome 371, Autumn 2017 Quiz Section 2 Meiosis Goals: To increase your familiarity with the molecular control of meiosis, outcomes of meiosis, and the important role of crossing over in generating genetic

More information

Ch 11.4, 11.5, and 14.1 Review. Game

Ch 11.4, 11.5, and 14.1 Review. Game Ch 11.4, 11.5, and 14.1 Review Game What happens to the chromosome number during meiosis? A It doubles B It stays the same C It halves D It becomes diploid Ans: C Gametes are A Sex cells B Sperm and eggs

More information

Mechanisms of Evolution Microevolution. Key Concepts. Population Genetics

Mechanisms of Evolution Microevolution. Key Concepts. Population Genetics Mechanisms of Evolution Microevolution Population Genetics Key Concepts 23.1: Population genetics provides a foundation for studying evolution 23.2: Mutation and sexual recombination produce the variation

More information

The Wright Fisher Controversy. Charles Goodnight Department of Biology University of Vermont

The Wright Fisher Controversy. Charles Goodnight Department of Biology University of Vermont The Wright Fisher Controversy Charles Goodnight Department of Biology University of Vermont Outline Evolution and the Reductionist Approach Adding complexity to Evolution Implications Williams Principle

More information

Perplexing Observations. Today: Thinking About Darwinian Evolution. We owe much of our understanding of EVOLUTION to CHARLES DARWIN.

Perplexing Observations. Today: Thinking About Darwinian Evolution. We owe much of our understanding of EVOLUTION to CHARLES DARWIN. Today: Thinking About Darwinian Evolution Part 1: Darwin s Theory Perplexing Observations Mystery of the Black Death?? What is evolution?? And what is this finch doing?!? We owe much of our understanding

More information

6 Introduction to Population Genetics

6 Introduction to Population Genetics 70 Grundlagen der Bioinformatik, SoSe 11, D. Huson, May 19, 2011 6 Introduction to Population Genetics This chapter is based on: J. Hein, M.H. Schierup and C. Wuif, Gene genealogies, variation and evolution,

More information

2. Map genetic distance between markers

2. Map genetic distance between markers Chapter 5. Linkage Analysis Linkage is an important tool for the mapping of genetic loci and a method for mapping disease loci. With the availability of numerous DNA markers throughout the human genome,

More information

Major questions of evolutionary genetics. Experimental tools of evolutionary genetics. Theoretical population genetics.

Major questions of evolutionary genetics. Experimental tools of evolutionary genetics. Theoretical population genetics. Evolutionary Genetics (for Encyclopedia of Biodiversity) Sergey Gavrilets Departments of Ecology and Evolutionary Biology and Mathematics, University of Tennessee, Knoxville, TN 37996-6 USA Evolutionary

More information

Biology 20 Evolution

Biology 20 Evolution Biology 20 Evolution Evolution: Modern synthesis: Individuals: Lamarck: Use and disuse: Inheritance of Acquired Traits: Darwin: Travelled: Galapagos Islands: What was the name of Darwin s book, which he

More information

Heterozygosity is variance. How Drift Affects Heterozygosity. Decay of heterozygosity in Buri s two experiments

Heterozygosity is variance. How Drift Affects Heterozygosity. Decay of heterozygosity in Buri s two experiments eterozygosity is variance ow Drift Affects eterozygosity Alan R Rogers September 17, 2014 Assumptions Random mating Allele A has frequency p N diploid individuals Let X 0,1, or 2) be the number of copies

More information

Outline. P o purple % x white & white % x purple& F 1 all purple all purple. F purple, 224 white 781 purple, 263 white

Outline. P o purple % x white & white % x purple& F 1 all purple all purple. F purple, 224 white 781 purple, 263 white Outline - segregation of alleles in single trait crosses - independent assortment of alleles - using probability to predict outcomes - statistical analysis of hypotheses - conditional probability in multi-generation

More information

Endowed with an Extra Sense : Mathematics and Evolution

Endowed with an Extra Sense : Mathematics and Evolution Endowed with an Extra Sense : Mathematics and Evolution Todd Parsons Laboratoire de Probabilités et Modèles Aléatoires - Université Pierre et Marie Curie Center for Interdisciplinary Research in Biology

More information

Evolution of Populations. Chapter 17

Evolution of Populations. Chapter 17 Evolution of Populations Chapter 17 17.1 Genes and Variation i. Introduction: Remember from previous units. Genes- Units of Heredity Variation- Genetic differences among individuals in a population. New

More information

4. Populationsgenetik

4. Populationsgenetik 4. Populationsgenetik Populations are never uniform, but individuals differ genetically and phenotypically. Population genetics is concerned with the study of the genetic composition of populations and

More information

19. When allele frequencies change as a result of the migration of a small subgroup of a population

19. When allele frequencies change as a result of the migration of a small subgroup of a population CP Biology: Evolution Name: Per: Directions: Use your textbook to help you answer the practice questions for each chapter. It is important that you READ the chapter sections and not just search for the

More information

Darwin s Observations & Conclusions The Struggle for Existence

Darwin s Observations & Conclusions The Struggle for Existence Darwin s Observations & Conclusions The Struggle for Existence 1 Voyage of the Beagle During His Travels, Darwin Made Numerous Observations And Collected Evidence That Led Him To Propose A Revolutionary

More information

UNIT V. Chapter 11 Evolution of Populations. Pre-AP Biology

UNIT V. Chapter 11 Evolution of Populations. Pre-AP Biology UNIT V Chapter 11 Evolution of Populations UNIT 4: EVOLUTION Chapter 11: The Evolution of Populations I. Genetic Variation Within Populations (11.1) A. Genetic variation in a population increases the chance

More information

e.g. population: 500, two alleles: Red (R) and White (r). Total: 1000 genes for flower color in the population

e.g. population: 500, two alleles: Red (R) and White (r). Total: 1000 genes for flower color in the population The Evolution of Populations What is Evolution? A change over time in the genetic composition of a population Human evolution The gene pool Is the total aggregate of genes for a particular trait in a population

More information

Chapter 22: Descent with Modification: A Darwinian View of Life

Chapter 22: Descent with Modification: A Darwinian View of Life Chapter 22: Descent with Modification Name Period Chapter 22: Descent with Modification: A Darwinian View of Life As you study this chapter, read several paragraphs at a time to catch the flow of ideas

More information

Mathematical Population Genetics II

Mathematical Population Genetics II Mathematical Population Genetics II Lecture Notes Joachim Hermisson June 9, 2018 University of Vienna Mathematics Department Oskar-Morgenstern-Platz 1 1090 Vienna, Austria Copyright (c) 2013/14/15/18 Joachim

More information

Population Genetics 7: Genetic Drift

Population Genetics 7: Genetic Drift Population Genetics 7: Genetic Drift Sampling error Assume a fair coin with p = ½: If you sample many times the most likely single outcome = ½ heads. The overall most likely outcome ½ heads n P = 2 k (

More information

Introduction to Wright-Fisher Simulations. Ryan Hernandez

Introduction to Wright-Fisher Simulations. Ryan Hernandez Introduction to Wright-Fisher Simulations Ryan Hernandez 1 Goals Simulate the standard neutral model, demographic effects, and natural selection Start with single sites, and build in multiple sites 2 Hardy-Weinberg

More information

(Write your name on every page. One point will be deducted for every page without your name!)

(Write your name on every page. One point will be deducted for every page without your name!) POPULATION GENETICS AND MICROEVOLUTIONARY THEORY FINAL EXAMINATION (Write your name on every page. One point will be deducted for every page without your name!) 1. Briefly define (5 points each): a) Average

More information

Population Genetics II (Selection + Haplotype analyses)

Population Genetics II (Selection + Haplotype analyses) 26 th Oct 2015 Poulation Genetics II (Selection + Halotye analyses) Gurinder Singh Mickey twal Center for Quantitative iology Natural Selection Model (Molecular Evolution) llele frequency Embryos Selection

More information

Evolution Test Review

Evolution Test Review Name Evolution Test Review Period 1) A group of interbreeding organisms (a species) living in a given area is called population 2) Give an example of a species. Ex. One wolf Give an example of a population.

More information

Educational Items Section

Educational Items Section Atlas of Genetics and Cytogenetics in Oncology and Haematology OPEN ACCESS JOURNAL AT INIST-CNRS Educational Items Section Hardy-Weinberg model Robert Kalmes, Jean-Loup Huret Institut de Recherche sur

More information

Evidence of Evolution

Evidence of Evolution Evidence of Evolution Biogeography The Age of Earth and Fossils Ancient artiodactyl Modern whale Ancestors of Whales Ambulocetus could both swim in shallow water and walk on land. Rodhocetus probably spent

More information