The basics of DNA testing for genealogists

By Kitty Munson Cooper
Blogging at blog.kittycooper.com

98% shared
DNA with him
99.7% with me

are NOT the same as
personal genome tests

Forensic DNA tests

23 pairs of chromosomes

Image of painted chromosomes - Courtesy of DeWitt Stetten, Jr., Museum of Medical Research
Image of painted (SKY) chromosomes - Courtesy of DeWitt Stetten, Jr., Museum of Medical Research

Three types of DNA tests

Y test for father's father's line

mtDNA for mother's mother's line

Autosomal DNA test for all your ancestors

Diagrams from the NIH http://ghr.nlm.nih.gov

Y Haplogroups

By Chakazul, via Wikimedia Commons [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)]

Y Haplogroups

By Chakazul, via Wikimedia Commons [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)]

Mitochondria under the microscope

Image Source: Dartmouth EM images, http://remf.dartmouth.edu/imagesindex.html
By User:Maulucioni via Wikimedia Commons [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)]

Mitochondrial Haplogroups

used by permission from http://stevemorse.org/genetealogy/dna.htm

Autosomal Inheritance by Steve Morse

Inheritance from 8 g-grandparents, courtesy of Angie Bush
Relationship Chart from ISOGG wiki http://www.isogg.org/wiki/Autosomal_DNA_statistics

Your autosomal test data

Why Do A DNA Test?

  • Am I who I think I am?
  • Ancestry Composition, as expected?
  • Find some distant cousins
  • Break a Genealogical Brick Wall

from Cece Moore's blog at http://www.yourgeneticgenealogist.com/2015/02/switched-at-birth-unravelling-century_27.html

My brother at 23andme.com

My brother at Ancestry.com

My brother at FamilyTreeDNA.com

My brother at GEDmatch.com

My brother at DNA.land

Where to test? It depends ...

  • 23andme.com
  • Ancestry.com
  • FamilyTreeDNA.com

http://blog.kittycooper.com/dna-testing/