Jewish Genealogical Society
of Greater Philadelphia (JGSGP)

Real World DNA Testing

Megan Smolenyak Smolenyak

www.honoringourancestors.com and www.genetealogy.com

What is “genetealogy”?

·        DNA testing done for the purpose of learning about one’s heritage

·        Mostly used for surname studies to determine if people share a common ancestor

·        But other types of tests are also available

What kind of tests are available?

·        Y-DNA

·        mtDNA

·        SNP

·        Genographic Project

·        BioGeographical/DNAPrint

·        Ethnic: African & Native American

·        Sorenson Molecular Genealogy Foundation

How are the tests done? http://www.davedorsey.com/dna.html

Who offers these tests?

·        The big 3: Family Tree DNA, Relative Genetics, DNA Heritage

·        Other players: Oxford Ancestors, DNAPrint Genomics, Trace Genetics, African Ancestry, GeoGene, GenbyGen, Roots for Real, GeneTree

·        Newest entrants: Ethnoancestry, DNA Fingerprint, Crucial Genetics, Chromosomal Laboratories

Most popular: Y-chromosome testing

·        Passed from father to son through generations

·        Line ends when male dies without issue or only has daughters

·        Women have to find male proxy for testing

·        Objective is usually to find a match

Surname projects:

·        Someone launches a project and invites all with that surname to participate

·        As results come in, matchmaking game begins

·        Participants are gradually divvied into clusters with their Y-DNA mates

 The matchmaking game:

·        Results presented in numbers of repeats at particular markers

·        When 2 or more people are tested, you look for (almost) identical results

Matchmaking example:

Y-DNA tests available in 3 tiers:

·        10-15 markers; 23-26 markers; 37-43 markers

·        More markers = greater accuracy; low resolution can produce occasional false positive

Case study: Smolenyaks

OTHER TYPES OF DNA TESTING

Mitochondrial (mtDNA)

·        Passed from mothers to sons & daughters, but sons don’t pass it on

·        Primarily a deep ancestry test (Seven Daughters of Eve by Bryan Sykes)

·        But also useful if you have a rare mtDNA haplotype, for specific genealogical conundrums, and if dealing with degraded remains

 

SNP

·        Deep ancestry Y-chromosome test (Journey of Man by Spencer Wells)

·        Predictable through standard test, but some take it for confirmation or to learn more

Genographic Project: www.genographic.com

Ethnic

·        African: Y & mtDNA versions; Can sometimes link to country or tribe (African Ancestry)

·        Native American: Y & mtDNA versions; Potential for disappointment (Trace Genetics and Relative Genetics)

BioGeographical (DNAPrint)

·        Presents results in percentages of Indo-European, Sub-Saharan African, Native American and East Asian

·        Somewhat shallow test, so potential for disappointment, controversy, and surprises!

Sorenson Molecular Genealogy Foundation

·        Aiming to collect 100,000 samples & family trees

·        Correlating genetic (Y, mtDNA & autosomal) and genealogical data (dates, places, names prior to 1900)

·        Query database by entering results from commercial lab

Perhaps the most important point to remember about all these tests is that . . . most only address certain portions of the family tree!

Resources:

·        GENEALOGY-DNA Mailing List:

http://lists.rootsweb.com/index/other/GENEALOGY-DNA.html

·        To find existing surname studies: search www.ysearch.org, www.ybase.org, www.smgf.org, and testing company sites, as well as http://www.worldfamilies.net

·        International Society of Genetic Genealogy: http://www.isogg.org/

·        Trace Your Roots with DNA: Using Genetic Tests to Explore Your Family Tree by Megan Smolenyak Smolenyak and Ann Turner

·        Genetic Genealogy Articles: http://honoringourancestors.com/library.html#three and http://www.genetealogy.com