If I could find volunteers, I would be willing to start a Theil surname Y-chromosomal DNA research project through FamilyTreeDNA (FTDNA).

The requirements would be that you are a male descendant of a direct paternal line of Theils (no recent male line adoptions or name changes) or variant of the surname. (I'm considering including variant spellings; Thiel, Thiele, Theile, Thejll, etc.) or you could get a male relative descended from a direct paternal line of Theil (or variant) to test on your behalf.

Interested parties should contact me via e-mail; sjtheil -at- bigplanet.com

http://www.familytreedna.com/surname.aspx