American trypanosomiasis chagas disease second edition, 2017. Evolution is difficult to observe in nature, but modeling an evolving population of edible treats effectively engages your students in the hardy weinberg principle and demonstrates what happens when hardy weinberg conditions are not met. Hardyweinberg by sam amey on prezi presentation software. Web server based software that estimates a variety of population genetic parameters and conducts a variety of sophisticated tests for departures from hardyweinberg, population differentiation, and linkage disequilibrium. The application of the hardyweinberg law of genetic equilibrium demonstrates that mutations, genetic drift and natural selection have a dramatic effect on gene frequency in a population. Discussing the meaning of hardyweinberg equilibrium and its requirements, then discussing the two equations and how they are useful. Apr, 2005 we evaluated the testing and reporting of hardyweinberg equilibrium hwe in recent genetic association studies, detected how frequently hwe was violated and estimated the power for hwe testing. Materials based on a class size of 30 one large aquarium or wading pool to serve as gene pool 60 index cards with a.
In this laboratory, you will apply this model by using your class as a sample population. Hardyweinberg lab laboratory 7, ap biology abstract through the random mating simulation completed in lab one the rabbit lab we were able to see how within nature lethal genes often are passed through a population of animals. Consider a simple situation with two alleles, a and a, at a single locus. Mar 04, 20 i discuss the theory of the lab briefly, then walk through a tutorial of how to set up a spreadsheet to model population genetics in microsoft excel. One equation used to model populations is the hardy weinberg equilibrium equation. Hardyweinberg equilibrium hwe is a null model of the relationship between allele and genotype frequencies, both within and between generations, under assumptions of no mutation, no migration, no selection, random mating, and infinite population size. Weinberg independently proposed that the frequency of alleles and genotypes in a population will remain constant from generation to generation if the population is stable and in genetic equilibrium. Using both cases and controls for testing hardyweinberg. Hardy weinberg equilibrium lab emilies phantastic labs. Hardyweinberg equilibrium test for analyzing population. Population genetics software for evolutionary analysis. Using computer and internet access, students will explore how a hypothetical gene pool changes from one generation to the next. For this simulation, we will assume that gender an genotype are irrelevant to mate selection. Population genetics and hardyweinberg mcat biology.
In order to simulate random mating, choose another student at random. We studied this process in ap bio using the straw fish lab. Hardyweinberg how can mathematical models be used to investigate the. The relationship between allele frequencies and genotype frequencies in populations at hardyweinberg equilibrium is usually described using a trait for which there are two alleles present at the locus of interest. This study was conducted at new tech high located in coppell, tx on december 7, 2015. Ap biology hardyweinberg spreadsheet tutorial on the app store. One equation used to model populations is the hardyweinberg equilibrium equation. Jul 11, 2015 the hardy weinberg law, which is the basis of population genetics, states, in part, that in a large randommating population at equilibrium i. The class is a population of randomly mating heterozygous individuals with an initial. The hardyweinberg principle is often hard for students to understand. The hardyweinberg principle is a fundamental principle in population genetics. The relationship between allele frequencies and genotype frequencies in populations at hardy weinberg equilibrium is usually described using a trait for which there are two alleles present at the locus of interest.
Court lab hw calculator a simple calculator to determine. This allowed some allele pairs to occur more frequently, which caused a certain genotype to become more common. The simple equation describes the expected allele frequency of a population that is not evolving. Ramal moonesinghe, office of minority health and health disparities, 4770 buford highway, mailstop e67, atlanta, ga 30341 email. The hardy weinberg principle is often hard for students to understand. Hardy weinberg lab report essays and research papers. The hw equilibrium is a valuable tool for population biologists because it serves as a baseline to measure changes in allele frequencies in a population. This calculator demonstrates the application of the hardyweinberg equations to loci with more than two alleles. A hardyweinberg equilibrium test for analyzing population genetic surveys with complex sample designs ramal moonesinghe correspondence to dr. Testing hardyweinberg one approach to testing the hypothesis that genotypes are in hardyweinberg proportions is quite simple. A hardy weinberg equilibrium test for analyzing population genetic surveys with complex sample designs ramal moonesinghe correspondence to dr. The subroutines below implement a fast exact hardy weinberg equilibrium test for snps as described in wigginton, et al. Feb 09, 2015 hardy weinberg lab laboratory 7, ap biology abstract through the random mating simulation completed in lab one the rabbit lab we were able to see how within nature lethal genes often are passed through a population of animals.
The hardy weinberg principle states that the allele and gene frequencies will stay constant from generation to generation as long as no other evolutionary influences come along. Forensic dna tests and hardyweinberg equilibrium science. The survivability of recessive alleles was examined by selecting red and white beads from a bowl to symbolize recessive and. The hardyweinberg equilibrium lab a simulation objective students will learn how changes in allele frequency affect population changes. One represents 100%, p represents the dominant alleles, q represents the recessive allele while 2pq are the heterozygous alleles, for example ff. The hardy weinberg law of genetic equilibrium provides a mathematical model for studying evolutionary changes in allelic frequency within a population. Hardy weinberg lab presentation by kallie supernor on prezi. Each line shows one of the three possible genotypes. The subroutines below implement a fast exact hardyweinberg equilibrium test for snps as described in wigginton, et al. The hardyweinberg law of genetic equilibrium provides a mathematical model for studying evolutionary changes in allelic frequency within a population. The application of the hardy weinberg law of genetic equilibrium demonstrates that mutations, genetic drift and natural selection have a dramatic effect on gene frequency in a population. We need to build a lab spreadsheet that will model how allele frequencies change through one life cycle of this imaginary population.
Assessment of the hardyweinberg proportion hwp in control subjects has been widely used as a quality control measure for identifying questionable genotypes in casecontrol association studies 1,2,3,4,5,6,7,8. The frequency of alleles can differ over generations as a result of genetic drift, natural selection, and mutation when a population violates equilibriums conditions. In this simulation, you will simulate 5 generations of offspring beginning with a parental population that are all heterozygous. Hardyweinberg activities, such as those in lab 8 of the ap biology lab manual 2001. In this virtual lab, you will learn to construct a genetic inheritance model and analyze scenarios when the assumptions of hardyweinberg equilibrium are violated. Hardyweinberg equilibrium in genetic association studies. The following lab is a delicious way to help your students understand the hardy weinberg principle. Lab 2 ap bio hardy weinberg math modeling using excel. Named for a pair of early 20th century scientists, this theorem is. This equation determines the allelicphenotypic frequencies of a population. Weinberg suggested a scheme whereby evolution could be viewed as changes in the frequency of alleles in a population of organisms. If natural selection occurs 25% of the time, genetic drift happens in a population of, and mutations happen 5% of the time, then each independently can eliminate a recessive allele from a population.
The hardy weinberg equilibrium states that both genotype and allele frequencies within a breeding population will remain constant from generation to generation only when there is an absence of evolutionary influences, such as gene flow. The student is able to justify data from mathematical models based on the hardy. Evolution is difficult to observe in nature, but modeling an evolving population of edible treats effectively engages your students in the hardyweinberg principle and demonstrates what happens when hardyweinberg conditions are not met. Pypop python for population genomics is an environment developed by the thomson lab for doing largescale population genetic analyses including. In reality, populations are always evolving due to one or multiple microevolutionary forces that change allele frequencies from generation to. Named for a pair of early 20th century scientists, this theorem is a mathematical model that shows. The user enters values for parameters controlling selection, mutation, migration, genetic drift, and inbreeding. One of the most important mathematical models in biology is called the hardyweinberg theorem. They established what is now known as the hardyweinberg principle. This flash program simulates drift, selection, mutation, migration and bottle neck affect. Population genetics software for evolutionary analysis allelea1 models evolution at a single locus in an ideal population of imaginary organisms. We hypothesized the recessive allele would be removed entirely from the population at the end of ten trials.
In this calculator, hardyweinberg equilibrium can be used to calculate the expected common homozygotes, expected heterozygotes, expected rare homozygotes and the frequency range of the 2 p and. Hardyweinberg equilibrium law states that allele and genotype frequencies in a population will remain constant from one generation to next generation in the absence of disturbing factors. Allelea1 models evolution at a single locus in an ideal population of imaginary organisms. Bioinformatics software and tools microsatellite data. The ap biology hardyweinberg spreadsheet tutorial app is the ideal tool for advanced placement biology teachers who want to create an interactive spreadsheet that uses the hardyweinberg equation to calculate allele and genotype frequencies in a. Labbench activity key concepts the hardyweinberg law of genetic equilibrium. Finally, you will perform computer simulations of population genetic processes during week 6. Gene combinations are a large part of the study of biology, and they are created simply by mixing genes. Genetic drift is defined as the unpredictable fluctuations in allele frequencies from one generation to the next. Hardyweinberg principle an overview sciencedirect topics.
Hardyweinberg equilibrium calculator science primer. The hardyweinberg principle is a mathematical model used to describe the equilibrium of two alleles in a population in the absence of evolutionary forces. The main objective of this lab was to explore how natural selection would affect a population under hardy weinberg equilibrium. Our data for case 1 did not end up matching the initially provided hardy weinberg data due to the addition of the simulated sexual reproduction, which allowed for randomization. Genes can fail to be in hardweinberg equilibrium for a number of reasons. It describes populations that are no longer undergoing evolution and thus reach a steady state. This is known as the hardyweinberg equilibrium hw equilibrium. Five conditions are required in order for a population to remain at hardy. The theory of recessive allele survivability and its relation to hairless rabbits was examined by using the hardy weinberg model. Evaluating the effects of natural selection in drosophila. I found the ap lab gave great instructions for how to set up the initial model. Time this lesson was designed for one or two 50minute class periods. The webbased version can be accessed via shesisplus web version.
The main objective of this lab was to explore how natural selection would affect a population under hardyweinberg equilibrium. The hardyweinberg principle is a null model in population genetics that is used to determine if evolution has occurred in a population. Today, hardyweinberg equilibrium hwe is a common hypothesis used in scientific domains ranging from botany weising, 2005 to forensic science council, 1996, and genetic epidemiology. A distribution of the genepop software as an r package. It also can convert data files to formats for use with other programs, including arlequin. If all of the hardyweinberg assumptions are met, we can conclude that the population is not evolving. As the simulation runs, the software plots a graph showing the frequency of allele a1 over time. It is assessed by considering whether the percentage of samples having each genotype are in the correct proportion, which can be tested using a chisquare goodness of fit test.
It states that the allele and genotype frequencies across a population will remain constant across generations in the. One of the most important mathematical models in biology is called the hardy weinberg theorem. To run allelea1 for the first time, you may need to hold down the control key, click on the allelea1 icon, and select open from the popup menu that appears. When the frequency is constant, the population is not. Sep, 2012 ap hardy weinberg simulation i taught this simulation for the first time this year.
In this calculator, hardyweinberg equilibrium can be used to calculate the expected common homozygotes, expected heterozygotes, expected rare homozygotes and the frequency range of. We evaluated the testing and reporting of hardyweinberg equilibrium hwe in recent genetic association studies, detected how frequently hwe was violated and estimated the power for hwe testing. Can anyone please suggest a software to test the hardyweinberg equilibrium. In this case, the recessive gene for no hair, which in turn disabled the rabbits to withstand the harsh climates thus. This calculator demonstrates the application of the hardy weinberg equations to loci with more than two alleles. Ap biology hardyweinberg spreadsheet tutorial on the app. Heather scoville is a former medical researcher and current high school science teacher who writes science curriculum for. This test is based on an efficient algorithm for enumerating the exact heterozygote probability distribution conditional on the number of minor alleles present in the sample.
The ap biology hardy weinberg spreadsheet tutorial app is the ideal tool for advanced placement biology teachers who want to create an interactive spreadsheet that uses the hardy weinberg equation to calculate allele and genotype frequencies in a fictional population. Hardy weinberg simulation case study random mating. The hardy weinberg law, which is the basis of population genetics, states, in part, that in a large randommating population at equilibrium i. Testing hardyweinberg equilibrium with a simple rootmean. You are also expected to become familiar with the hardy weinberg principle, and how it can be used as a null model to determine if evolution has occurred in a population. Red represents the dominant allele t and green represents the recessive allele t. Tfpga, short for tools for population genetic analyses, is a program for the analysis of allozyme and molecular population genetic data that calculates descriptive statistics, genetic distances, fstatistics, and tests for hardyweinberg equilibrium see also fstat and gda. Ap bio hardy weinberg simulation lab part 1 youtube.
The hardy weinberg equation can be used to test whether a population is evolving. The rest of the models are from my students who gave permission to have them posted. The evolutionary influences can be things such as mutation, mate choice, selection, genetic drift, gene flow, and meiotic drive. The essentiality of reporting hardyweinberg equilibrium. This lab used straws to represent the fish in a pond. With the redesigned ap biology curriculum stressing statistical analysis, this activity will help reinforce the advanced concepts. Dec 30, 2015 ap bio hardy weinberg simulation lab part 1.