DNA in Genealogy:
Testing, Tools and Techniques
Feb. 8 – March 15, 2021
Classes Monday, 10:30 a.m. – noon
Free Six-Part Series
The Office of Senior and Social Services (OSSS) is pleased to bring this series to Bernalillo County residents. The meeting will open up five minutes prior to start time so individuals may enter and be ready to begin at 10:30 a.m. Classes are recorded for playback.
The Science of Genetic Genealogy
We will explore the uses of Y-DNA, mitochondrial DNA and autosomal DNA. We will examine how DNA is inherited from one generation to the next and how DNA can help us corroborate our documentary evidence and give us leads for further investigation. We will explore chromosomes, DNA, recombination, SNP’s, STR’s, meiosis, haplotypes, haplogroups, alleles and much more.
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About the Presenter
Martin Brady
Marty grew up in Pittsburgh, Pennsylvania. He obtained a B.S. degree in Biochemistry from the University of Pittsburgh in 1975 and then worked as a research assistant at the University of Pittsburgh. Marty was a co-recipient of the Frank R Blood Award which was awarded for an outstanding paper published from that research. Marty received a M.S. degree in Forensic Chemistry in 1980 from the University of Pittsburgh.
In September 1980, Marty took a position with the Albuquerque Police Department (APD) Criminalistics unit. He worked as a Criminalist for four years and then for seven years as the Criminalistics Supervisor in charge of the chemists and biologists in the forensic lab. Marty was instrumental in getting the DNA lab established at APD in 1989. APD had the first forensic DNA lab in New Mexico.
In 1991, Marty accepted the position of Assistant Director of Toxicology at S.E.D. Medical Laboratories. In 1995, Marty was promoted to Director of Toxicology at S.E.D., a position he held until 2012 when S.E.D. was sold. Marty finished out his career as the Chemistry Supervisor at the DPS Forensic lab in Santa Fe. He began genealogical research in June 2016 to prepare for a trip to Ireland. He retired at the end of 2017 and has been involved with the Albuquerque Genealogical Society (AGS) ever since. He is currently the immediate past president of AGS.
The Science of Genetic Genealogy
Handouts
Summary of Topics
Human Genome Project (HGP): The Human Genome Project has made Genetic Genealogy possible. We now know the number and the locations of almost all the mutations in our genome. Mutations allow us to differentiate one person or group of people from another. Without mutations, we would all have identical DNA.
Mitochondrial DNA: Mitochondrial DNA (mtDNA) is inherited from mother to children, generation after generation. Because mtDNA does not crossover and only one type of mtDNA usually exists in any person, it can be used to categorize people into mtDNA haplogroups. On average, mutations in mtDNA occur every 10,000 years, but a mutation can occur in any generation. mtDNA is composed of only 16569 base pairs and behaves much like bacterial DNA, so mtDNA does not behave the same way as nuclear DNA. mtDNA can be used to corroborate a theory of inheritance and it is excellent exclusionary evidence for genealogical hypotheses.
Y-DNA: Y-DNA is inherited from father to son relatively unchanged from generation to generation. Y- DNA can therefore be used for deep ancestry research. It is also often used in surname research as it is tied to the male line. Short Tandem Repeats (STRs) are used for more recent heritage as they mutant more quickly than Single Nucleotide Polymorphisms (SNPs). SNPs are used for deeper ancestry investigation. STRs can be used to find cousins. SNPs are not usually used for finding cousins. That being said, if all males in the world were Y-DNA SNP tested, we might be able to link most male relatives.
Autosomal DNA: Autosomal DNA is valuable in genealogical research going back 5 to 7 generations, but because the DNA is recombined (crossovers and random assortment), every generation contributes less and less to your DNA. Parents (50%), grandparents (~25%), great grandparents (~12.5%), 2X great grandparents (~6.25%), etc. Studies have shown that you may not share any atDNA with a 3rd cousin.
Autosomal DNA is analyzed using DNA microarrays (chips). The first step to ethnicity estimates and DNA matching is phasing the microarray results. Each SNP analyzed on the microarray contains information from mom and dad. In order to correctly match customers and estimate ethnicity, the SNP values must first be correctly assigned to either mom or dad. This is done using statistical algorithms. The statistical algorithms can misassign SNPs to the wrong parent. Because there is a greater chance of misassigning SNP values in small segments, small segments are not as reliable for DNA matching.
Ethnicity Estimates: Ethnicity estimates basically compare a customer’s DNA to the DNA of a reference database. All the companies test different SNPs, use different reference data bases and different algorithms for their estimations, so results can vary from one company to another. However, they are usually very similar.
Health: Some SNPs are associated with certain health conditions. If you get a DNA health report from one of the Direct to Consumer companies, it is recommended that you discuss the results with your doctor before making any health decisions based on those results.
Definitions:
Allele - one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.
Amino acids - organic compounds that combine to form proteins.
Gene - A gene is a DNA segment (region on a chromosome) that codes for the production of a protein (or RNA).
Genotype - the genetic constitution of an individual organism. It includes both sets of chromosomes (i.e., those inherited from mom and from dad).
Haplogroup - A haplogroup is a genetic population group of people who share a common ancestor on the patriline or the matriline. Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations. Haplogroups are groups of similar haplotypes.
Haplotype - A haplotype is defined as the combination of alleles for different polymorphisms that occur on the same chromosome. It can refer to all the alleles on a particular chromosome or a specific set of alleles (i.e., STRs). It is a contraction of the terms haploid and genotype.
Heteroplasmy - describes the situation in which two or more mtDNA variants exist within the same cell.
Heterozygous - having two different alleles of a particular gene or genes.
Homozygous is a genetic condition where an individual inherits the same alleles for a particular gene from both parents.
Meiosis - a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes (sperms & eggs).
Phylogenetic Tree - A phylogenetic tree, also known as a phylogeny, is a diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor.
Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. Proteins are required for the structure, function, and regulation of the body's cells, tissues, and organs. Each protein has unique functions. Proteins are essential components of muscles, skin, bones and the body as a whole. Examples of proteins include whole classes of important molecules, among them enzymes, hormones, and antibodies.
Recombination - the formation of new combinations of genes in progeny that did not occur in the parents by the processes of crossing-over and independent assortment.
STR - An STR is a short tandem repeat. This is a place in your DNA code where a letter sequence is repeated. For example, AGTAAGTAAGTA is three repeats of the sequence AGTA. STRs have a fast mutation rate. Some STRs mutate faster than others. When they change, it is an increase or decrease in the number of repeats. STR values change back (back mutate) more common.
SNP - A SNP is a single nucleotide polymorphism. That means that it is a single small change in your DNA code. These changes are rare. Once they happen, they seldom change back (back mutate).
References:
Articles and Websites:
Sequencing Human Genome: The Contributions of Francis Collins and Craig Venter https://www.nature.com/scitable/topicpage/sequencing-human-genome-the-contributions-of- francis-686
Genetic Mutation by Suzanne Clancy, Ph.D., 2008 https://www.nature.com/scitable/topicpage/genetic-mutation-441/
Misconceptions about mitochondria and mammalian fertilization: Implications for theories on human evolution, Friderun Ankel-Simons and Jim M. Cummins, 1996 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC19448/
Mutation
https://www.genome.gov/genetics-glossary/Mutation
STRs
A Brief Review of Short Tandem Repeat Mutation
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5054066/
Websites:
SNPs:
www.SNPedia.com
www.Promethease.com
SNP Index on www.ISOGG.org (International Society of Genetic Genealogy) https://isogg.org/wiki/FT_SNP_index
Other Geneology websites:
DNA eXplained - Genetic Genealogy → https://dna-explained.com/
www.DNA-Central.com (subscription) www.DNAPainter.com https://www.eupedia.com/genetics/human_genome_and_genetics.shtml http://scaledinnovation.com/gg/snpTracker.html
www.GeneticHomeland.com
Legacy Family Tree Webinars → https://legacy.familytreewebinars.com/ If you want to try out some webinars before purchasing, check out the FREE webinars first, located under WEBINAR LIBRARY here → https://familytreewebinars.com/archived_webinars_free.php
Videos:
What is DNA and How Does it Work (part of a “Stated Clearly” series of YouTube videos on a number of subjects.) https://www.youtube.com/watch?v=zwibgNGe4aY
Blaine Bettinger: Advanced DNA Techniques: Deductive Chromosome Mapping
https://familytreewebinars.com/download.php?webinar_id=1233
Blaine Bettinger: The Stories Behind the Segments
https://familytreewebinars.com/download.php?webinar_id=904
“How Y DNA Can Help Your One Name Study” by Dr. Maurice Gleeson https://www.youtube.com/watch?v=vOx971zy6LI
“Using Y-DNA to Research Your Surname” by Dr. Maurice Gleeson
https://www.youtube.com/watch?v=u5xHtppMNJY
“Exploring New Y-DNA Horizons with Big Y-700” by Dr. Iain McDonald https://familytreewebinars.com/download.php?webinar_id=1443
Books:
- “The Family Tree Guide to DNA Testing and Genetic Genealogy” by Blaine Bettinger
- “Genetic Genealogy in Practice” by Blaine Bettinger and Debbie Parker Wayne
- “Advanced Genetic Genealogy: Techniques and Case Studies”,
Editor: Debbie Parker Wayne
- “Tracing Your Ancestors Using DNA, A guide for Family Historians” edited
by Graham S. Holton
- “Genome” by Matt Ridley
- “Genetics for Dummies” by Tara Rodden Robinson “The Seven Daughters of Eve”
by Bryan Sykes “Viking, Saxons and Celts” by Bryan Sykes
- “Who We Are and How We Got Here” by David Reich
- “The Genealogist’s Guide to Y-DNA Testing for Genetic Genealogy” by David Vance
- “Forensic Genealogy” by Colleen Fitzpatrick, PhD and Andrew Yeiser
Facebook groups:
Genetic Genealogy Tips & Techniques (private group; ask to join) →
https://www.facebook.com/groups/geneticgenealogytipsandtechniques
Autosomal DNA-GEDmatch-FTDNA-23andme-Ancestry-MyHeritage
(private group; ask to join) → https://www.facebook.com/groups/DNAandGenealogy
Albuquerque Genealogical Society:
Recorded webinars on our website → https://abqgen.org/abcs-dna-videos/
Upcoming schedule of webinars → https://abqgen.org/abcs-dna-2021-programs/
Information about our DNA Special Interest Group that meets the 1st Thursday of every month → https://abqgen.org/learning-resources/sig/
This series will use webinar settings in Zoom which disables audio and video of the registrants, but can enable for questions when needed. All registrants are sent a reminder email an hour before each class with the link to join and the password.
If you have specific questions for the class, please email BCOSSS@bernco.gov attn: Veronica Cordova, Subject: DNA Question.
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