Statistical weights of single source DNA profiles Forensic Bioinformatics (www.bioforensics.com) Dan E. Krane, Wright State University, Dayton, OH Forensic.

Slides:

Advertisements

Similar presentations

Statistical Weights of DNA Profiles Forensic Bioinformatics ( Dan E. Krane, Wright State University, Dayton, OH.

Advertisements

Attaching statistical weight to DNA test results 1.Single source samples 2.Relatives 3.Substructure 4.Error rates 5.Mixtures/allelic drop out 6.Database.

Population Genetics 1 Chapter 23 in Purves 7 th edition, or more detail in Chapter 15 of Genetics by Hartl & Jones (in library) Evolution is a change in.

Two-locus systems. Scheme of genotypes genotype Two-locus genotypes Multilocus genotypes genotype.

Genetic Statistics Lectures （５） Multiple testing correction and population structure correction.

Lab 3 : Exact tests and Measuring of Genetic Variation.

Lab 3 : Exact tests and Measuring Genetic Variation.

SNP Applications statwww.epfl.ch/davison/teaching/Microarrays/snp.ppt.

Forensics and DNA Statistics Harry R Erwin, PhD CIS308 Faculty of Applied Sciences University of Sunderland.

Expected Value Suppose it costs $2 to get a ticket from the parking ticket machine. Suppose if you are caught without a ticket, the fine is $20. Suppose.

BIOE 109 Summer 2009 Lecture 5- Part I Hardy- Weinberg Equilibrium.

KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.

 Read Chapter 6 of text  Brachydachtyly displays the classic 3:1 pattern of inheritance (for a cross between heterozygotes) that mendel described.

BMI 731- Winter 2005 Chapter1: SNP Analysis Catalin Barbacioru Department of Biomedical Informatics Ohio State University.

Fundamentals of Forensic DNA Typing Slides prepared by John M. Butler June 2009 Appendix 3 Probability and Statistics.

Copyright © McGraw-Hill Education. Permission required for reproduction or display. Chapter 14 Constant Allele Frequencies.

Population Genetics A.The Hardy-Weinberg principle B.Factors that can change allele frequencies.

DATA ANALYSIS Module Code: CA660 Lecture Block 2.

Review of Mendelian Genetics and Population Genetics Prep for lab tomorrow: Chapter 5.

Population Genetics: Populations change in genetic characteristics over time Ways to measure change: Allele frequency change (B and b) Genotype frequency.

JS 115- Population Genetics- Assessing the Strength of the Evidence I.Pre class activities a.Quiz b.Review Assignments and Schedules c.Return and Review.

Evolutionary Concepts: Variation and Mutation 6 February 2003.

Genetic Statistic Application in Forensic Science Arthur J. Eisenberg, PhD Professor and Chairman Department of Forensic and Investigative Genetics Co-Director.

Population Genetics. Macrophage CCR5 CCR5-  32.

Forensic Statistics From the ground up…. Basics Interpretation Hardy-Weinberg equations Random Match Probability Likelihood Ratio Substructure.

Population Genetics Learning Objectives

Statistical weights of mixed DNA profiles Forensic Bioinformatics ( Dan E. Krane, Wright State University, Dayton, OH Forensic DNA.

Genetic Variation and Mutation. Definitions and Terminology Microevolution –Changes within populations or species in gene frequencies and distributions.

Hardy-Weinberg equilibrium. Is this a ‘true’ population or a mixture? Is the population size dangerously low? Has migration occurred recently? Is severe.

Genetic Drift Random change in allele frequency –Just by chance or chance events (migrations, natural disasters, etc) Most effect on smaller populations.

The Hardy-Weinberg Principles Changing Populations.

Population Genetics is the study of the genetic

DNA evidence The DNA Double Helix Consists of so-called nucleobases always in pairs A-T, C-G. One part of the pair is inherited from the mother, the other.

Thinking About DNA Database Searches William C. Thompson Dept. of Criminology, Law & Society University of California, Irvine.

Lecture 21 Based on Chapter 21 Population Genetics Copyright © 2010 Pearson Education Inc.

PV92 PCR/Informatics Kit Population Genetics and Informatics.

Genes in human populations n Population genetics: focus on allele frequencies (the “gene pool” = all the gametes in a big pot!) n Hardy-Weinberg calculations.

Artifacts and noise in DNA profiling Forensic Bioinformatics ( Dan E. Krane, Wright State University, Dayton, OH Forensic DNA Profiling.

1 Population Genetics Definitions of Important Terms Population: group of individuals of one species, living in a prescribed geographical area Subpopulation:

Population Genetics The Study of how Populations change over time.

Allele Frequencies: Staying Constant Chapter 14. What is Allele Frequency? How frequent any allele is in a given population: –Within one race –Within.

Statistical Analysis of DNA Simple Repeats –Identical length and sequence agat agat agat agat agat Compound Repeats –Two or more adjacent simple repeats.

Mechanisms of Evolution  Lesson goals:  1. Define evolution in terms of genetics.  2. Using mathematics show how evolution cannot occur unless there.

Lecture 14: Population Assignment and Individual Identity October 8, 2015.

Implications of database searches for DNA profiling statistics Forensic Bioinformatics ( Dan E. Krane, Wright State University, Dayton,

Maximum-likelihood estimation of admixture proportions from genetic data Jinliang Wang.

Measuring Genetic Variation in Natural Populations Historical Method: Examining protein variation via electrophoresis Modern Method: DNA sequencing and.

The Time Has Come to Analyze DNA Profile Databases Forensic Bioinformatics ( Dan E. Krane, Ph.D., Wright State University, Dayton,

KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.

KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.

Objective: Chapter 23. Population geneticists measure polymorphisms in a population by determining the amount of heterozygosity at the gene and molecular.

Chapter 23: Evaluation of the Strength of Forensic DNA Profiling Results.

Exercise 1 DNA identification. To which population an individual belongs? Two populations of lab-mice have been accidentally put in a same cage. Your.

Individual Identity and Population Assignment Lab. 8 Date: 10/17/2012.

Chi square and Hardy-Weinberg

What can go wrong with DNA profiling Dan E. Krane, Wright State University, Dayton, OH Forensic DNA Profiling Video Series Forensic Bioinformatics (

Observer effects in DNA profiling Dan E. Krane, Wright State University, Dayton, OH Forensic DNA Profiling Video Series Forensic Bioinformatics (

By Bryce Perry and Cecil Brown

Modern Evolutionary Biology I. Population Genetics A. Overview Sources of VariationAgents of Change MutationN.S. Recombinationmutation - crossing over.

Population Genetics I. Basic Principles. Population Genetics I. Basic Principles A. Definitions: - Population: a group of interbreeding organisms that.

8 and 11 April, 2005 Chapter 17 Population Genetics Genes in natural populations.

POINT > Define Hardy-Weinberg Equilibrium POINT > Use Hardy-Weinberg to determine allele frequencies POINT > Define “heterozygous advantage” POINT > Describe.

Disputed DNA Stats for a Low-level Sample: A Case Study By Dan Krane – Carrie Rowland –

Seventh Annual Prescriptions for Criminal Justice Forensics Program Fordham University School of Law June 3, 2016 DNA Panel.

HS-LS-3 Apply concepts of statistics and probability to support explanations that organisms with an advantageous heritable trait tend to increase in proportion.

Generating forensic DNA profiles

Statistical Analysis of DNA

Statistical Weights of DNA Profiles

Population Genetics: Selection and mutation as mechanisms of evolution

Presentation transcript:

Statistical weights of single source DNA profiles Forensic Bioinformatics ( Dan E. Krane, Wright State University, Dayton, OH Forensic DNA Profiling Video Series

DNA statistics Coincidental 13 locus DNA profile matches are exceedingly rare Several factors can make statistics less impressive –Mixtures –Incomplete information –Relatives

DNA profile

Comparing electropherograms Evidence sampleSuspect #1’s reference EXCLUDE

Comparing electropherograms Evidence sampleSuspect #2’s reference CANNOT EXCLUDE

What weight should be given to DNA evidence? Statistics do not lie. But, you have to pay close attention to the questions they are addressing.

What weight should be given to DNA evidence? Statistics do not lie. But, you have to pay close attention to the questions they are addressing. RMP: The chance that a randomly chosen, unrelated individual from a given population would have the same DNA profile observed in a sample.

Single source samples Formulae for RMP: At a locus: Heterozygotes: Homozygotes: Multiply across all loci p2p2 Statistical estimates: the product rule 2pq p2p2 p2p2 p2p2 xxxx xxxx xxxx x x

0.1454x0.1097x2 Statistical estimates: the product rule

3.2%6.0%4.6%1.2% 9.8%9.5%6.3%2.2%1.0% 2.9%5.1%29.9%4.0% 1.1%6.6% XXXX XXXXX XXXX X Statistical estimates: the product rule 1 in 609,000,000,000,000,000,000 1 in 609 quintillion = xx

Two underlying assumptions of the product rule: The events being evaluated are independent –In this context, the events are the observation of specific alleles The frequencies of the events are known –In this context, at what frequency does each allele occur?

Population genetics: testing for independence Hardy-Weinberg equilibrium (HWE) –A test of the independence of alleles within a locus Linkage equilibrium –A test of the independence of alleles between loci

DNA profile

DNA statistics Coincidental 13 locus DNA profile matches are exceedingly rare Corrections can be made for population substructure RMP statistics described in terms of quintillions are common

Two underlying assumptions of the product rule: The events being evaluated are independent –In this context, the events are the observation of specific alleles The frequencies of the events are known –In this context, at what frequency does each allele occur?

What weight should be given to DNA evidence? Statistics do not lie. But, you have to pay close attention to the questions they are addressing. RMP: The chance that a randomly chosen, unrelated individual from a given population would have the same DNA profile observed in a sample.

What is the relevant population? 1 in 609 quintillion

Popular vote in 2008 by county. McCain won red counties, Obama won blue counties. How would you determine the frequency of Obama supporters in North Carolina? Obama N.C. 50.2%

Popular vote in 2008 by county. McCain won red counties, Obama won blue counties. How would you determine the frequency of Obama supporters in North Carolina? Obama N.C. 50.2% Region 59.6%

Popular vote in 2008 by county. McCain won red counties, Obama won blue counties. How would you determine the frequency of Obama supporters in North Carolina? Obama N.C. 50.2% Region 59.6% U.S. 52.9%

Popular vote in 2008 by county. McCain won red counties, Obama won blue counties. How would you determine the frequency of Obama supporters in North Carolina? Obama N.C. 50.2% Region 59.6% U.S. 52.9% Utah? 35.5% ?

DNA statistics Coincidental 13 locus DNA profile matches are exceedingly rare Several factors can make statistics less impressive –Mixtures –Incomplete information –Relatives

Statistical weights of single source DNA profiles Forensic Bioinformatics ( Dan E. Krane, Wright State University, Dayton, OH Forensic DNA Profiling Video Series