Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Genealogy and Family History: DNA

A guide to assist those interested in starting a family history project.

About DNA and Genealogy

Many people who are interested in genealogy also find that doing DNA testing supplements their research into their family history.  Which type of DNA test you take should be based on what information you are interested in finding. The most common types of DNA testing done for genealogy are Autosomal, Y and Mt.  There are many companies that sell these tests (Ancestry, FamilyTreeDNA, 23&Me, My Heritage, etc.) to the public. Their websites often have very informative articles, links, white papers, etc. to assist you in understanding the results. If you are interested in comparing different companies DNA test results with others, there are websites such as GEDMatch that will assist you with uploading the data. Do your due diligence before you do any DNA tests and/or share your information with others. Read and understand the privacy policy of each vendor/website and the complete terms of service before you proceed.

Basic DNA

Extract Your Own DNA as an Experiment

Genealogy and DNA Testing

The Genetic Genealogist & Other DNA Blogs

Which Companies Do DNA Testing for Ancestry?

Exporting Your Tree Out of as a GedCom File

What is a GEDCOM File?
GEnealogy Data COMmunications, or, the universal file format for genealogy databases that allows users of different software programs to share their data with others.

Adding DNA Test Results into FamilySearch

Instructional Videos on DNA & Ancestry

Transferring your autosomal DNA results to other Databases

DNA Triangulation

GedMatch & GedMatch Genesis

Ancestry's New ThruLines

Create a Surname Table


FamilyTreeDNA Results Explained: Family Finder Match Comparison (ICW, Matrix, Chromosome Browser)

FamilyTreeDNA Results Explained: mtDNA Matching & Genealogy

FamilyTreeDNA Webinar: X Chromosome Matches in Family Finder



Admixture refers to ancestry from more than one recent population group. Many people today have ancestry from more than one population and/or location.


An allele is a genetic variant at a specific point, locus, in our genetic code.

Ancestral Haplotype

In genetic genealogy, the ancestral haplotype is the set of marker values of your ancestor.

Autosomal DNA
genetic material inherited equally from mother and father. It’s less useful genealogically than Y-DNA and mtDNA because it mutates more often. Genetic tests to determine ethnic origins—African, Native American, Viking—typically analyze autosomal DNA.

a threadlike strand of DNA that carries genes and transmits hereditary information.

Common Ancestor
Person through whom two or more persons claim descent or lineage

Degree of relationship between persons who descend from a common ancestor. A father and son are related by lineal consanguinity, uncle and nephew by collateral sanguinity.

the molecule that contains each cell’s genetic code, organized into 23 pairs of chromosomes. Genetic genealogy tests analyze your Y-DNA, mtDNA or autosomal DNA.

GEnealogy Data COMmunications, or, the universal file format for genealogy databases that allows users of different software programs to share their data with others.

a hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome, and determines a particular characteristic in an organism.

The study of your family’s history; the process of tracing your ancestors back through time.

Genetic Marker
represents a specific location on a chromosome where the basic genetic units exist in a variable number of repeated copies

the compilation of multiple genetic markers; serves as the unique genetic identifier for any given individual.

an identification of the genetic group your ancient ancestors (10,000 to 60,000 years ago) belonged to; sometimes referred to as your branch of the world’s family tree

collectively, the marker values on your Y-DNA test results

Direct line of descent from an ancestor; progeny

Maternal Line
Line of descent traced through the mother's ancestry

Mitochondrial DNA
genetic material both males and females inherit from their mothers. Because it’s passed down mostly unchanged from mothers to daughters, mtDNA can tell you about your maternal line—but the results reveal only “deep ancestry,” not definitive links to recent generations.

Nucleic Acids

Nucleic acids are the basic components of our genetic code. DNA is made up of four types of nucleic acids: adenine (A), cytosine (C), guanine (G), and thymine (T).


Recombination is the mixing of the DNA on each chromosome that you receive from your mother and father. Different chromosomes and different parts of each chromosome are more or less likely to recombine in a single generation.

Last name, family name

Y Chromosome
genetic material passed down from father to son. Because surnames also pass from father to son, Y-DNA tests can confirm (or disprove) genealogical links through a paternal line. Y-DNA surname studies are the most popular application of genetic genealogy.

For more terms visit

DNA/Genealogy Books in the TMCC Library