I have just learned that the male line of a family can be traced via Y chromosome DNA.There are several firms doing the test for genealogical purposes.
I would like to start a site for the Langstaff family in Canada, USA and UK, to see if one can trace the Irish Langstaff's and any other Langstaff family to those found in County Durham and Yorkshire.
My oldest Langstaff is William who married Elisabeth Warren in Wexford and came to Grenville Co, Ontario about 1825, his brother John came in 1832.
I also follow an Andrew Langstaff who came from Ireland to Gloucester Twp. near Ottawa, and I think they may be related and DNA seems to be the only answer.
The test costs $99US, and the firm I have been in contact with will help in the analysis.The more we could test, the more interesting would be the results.But one must be prepared for any odd result as well.
Send me an e_mail if any Langstaff male is interested, and I will collate the list.