Clan Donnachaidh, which includes the surname Duncan, has a Y-DNA project.
(DNA is short for Deoxyribonucleic Acid)
FamilyTreeDNA website: http://www.familytreedna.com/      
Join the DNA project: http://www.familytreedna.com/public/clandonnachaidh/
The Clan Donnachaidh DNA Reports       2006.01   2006.02   2007.01

One or more descendants of the following early Duncans have already registered their Y-DNA. If you're also a descendant, please participate and find your genetic cousins. You can read more about these ancestors; click on any name which is highlighted. Please note that the information presented is furnished by the respective descendant, and is not edited nor verified by the Association.

Charles Duncan, Banff, Scotland.htm

Thomas Duncan, 1700-1776, Cumberland Co, PA

Robert Long Duncan, 1837, Fayette Co, PA

Thomas Dunkin, abt 1707-1760, Argyl Co, Scotland, d.1760 Lancaster Co, PA

James Duncan Sr, MD, d. Breckenridge Co, KY

Rev. Landon Duncan, b. ca 1786, Fauquier Co, VA

James (John) Duncan, Stirling, Scotland.htm

Hugh Duncan, Renfrewshire, Scotland, Anderson Co, SC

George Duncan, b. ca 1630, Scotland 

Brantley Duncan, b. 1821, SC>GA

Benjamin Duncan, b. 1755, VA

William Duncan, B. 1821, Cape Girardeau, MO

Robert Duncan, from Scotland ca 1810-1825

James Duncan, 1818-1905 of Aberdeenshire, Scotland

David Duncan, b. 1793, Galston, Ayrshire, Scotland

Charles Browning Duncan, b. 1812, Logan Co, KY

William A. Duncan, b. 1803, Robertson Co, TN

William Duncan, B. 1785-86, d. 1836, TX

James Jordan Ashley, B. ca 1788, d. 1850, TN

John Duncan, b. 1720-1725, Fauquier Co, VA

Marshall Duncan the Elder, b. ca 1705, Prince William Co, VA, d. 1777, Surry Co, NC

William Duncan, b. 1764-1771, TN, AL and NC.

Eli Duncan, b. 1823, TN

John Duncan, b. ca 1790-1795, GA or SC, d. 1844 Warren Co, TN 

James Duncan, b. 1791 PA, to Knox Co, OH

James Duncan, b. 1691, d. ca 1740, Scotland

James Duncan, 1778, KY

Benjamin Duncan, b. ca 1765, VA? d. 1820, KY

Benjamin Floyd Duncan, b. 1861, Carroll Co, VA

Joshua Duncan, b. 1799, Fairfax(?) Co, VA

Solomon Duncan, 17??-1862, Scotland>Nova Scotia

George Washington Duncan, b. ca 1778 SC?, d. 1849 Travis Co, TX

James Duncan, b.  1806 Lincoln? Co, KY, to Putnam Co, IN

John Duncan b. 1784, of Robertson Co, TN, d. 1868

John Duncan, b. 1700 Scotland; d. 1745/46 VA

David Duncan, d. 1745, VA

William Duncan III

John Duncan ca 1735-1806, VA>Orange/Randolph Co, NC

Ambrose Harrison Duncan, 1745-1828

Anderson A. Duncan, 1800, NC 

George Duncan, Ballymoney, Ireland

William T Duncan, 1787, PA

William Duncan, Culpeper Co, VA

John Duncan Jr, Ashe Co, NC

William Duncan, born 1744 Scotland

Many Duncan descendants have already proved their genetic relationship through Y-DNA tests conducted by FamilyTreeDNA. These Duncans are getting closer to finding their mutual Duncan ancestor. See this chart of  relationships. The ultimate success of the DNA project depends heavily on the number of Duncans who can document their lineage for several generations back, and who have their DNA tested. 

To encourage further participation, we currently are offering complimentary membership in our Association--with free access to member-only research files--to new membership applicants who agree to have their DNA tested by FamilyTreeDNA, and to share the results among related Duncans. 

A female descendant can also participate by having a male Duncan relative take the DNA test on her behalf. Click here to to see how to join this project.

Please contact: C. T. Duncan for further details. 

Associated Websites:

Our contributing genealogist, Mary Ann (Duncan) Dobson's Site
http://homepages.rootsweb.com/~dobson

Our editor, C. T. "Terry" Duncan's Homepage
http://mywebpages.comcast.net/cduncan22/

The Clan Duncan Society based in Scotland at 
http://www.clan-duncan.co.uk

The Clan Donnachaidh website: 
http://www.donnachaidh.com