Joining the Study

All adult males around the world with the surname Irwin, or its variant spellings such as Arvin, Ervin, Erwin, Irvin, Irvine, Irving and Urwin, are invited to participate in FTDNA's Irwin Clan Surname Project and in this independent Clan Irwin Surname DNA Study.  Females are welcome to participate if they can first persuade an adult male relation with such a surname to take a Y-DNA test on their behalf.  Adult males with other surnames are also welcome if their Y-DNA signature is a close match with an Irwin tester.

There is no membership fee or admission form.  Membership of both FTDNA's Irwin Clan Surname Project and this Study are achieved automatically by ordering a Y-DNA test on-line at:  or, if you already have a Y-DNA test and its results meet the criteria above, by asking FTDNA ( to add your name to their Irwin Clan Surname project.

For most prospective testers we recommend FTDNA’s 37-marker yDNA STR test at $119, plus a shipping charge of $9.95 (USA & international).  Alternatively their 12-marker test at $59 (plus shipping charge) offers a cheap start, but it is usually found desirable to subsequently upgrade to 37 markers.  FTDNA no longer offer discounted rates for project members, or their 25- and 67-marker tests.  Their 111-marker STR test remains available at $249 and they also offer various other upgrades and add-ons, but we generally now only recommend upgrading to their BigY700 test (see "Choosing your next test").

 Four ways to reduce the cost of a DNA test may be considered:

We have chosen FamilyTreeDNA (“FTDNA”) as our preferred testing company because, in the absence of any international standard for yDNA tests, it has the largest data bank.  FTDNA was established in Houston, Texas in 2000 and is now the only company offering a comprehensive series of yDNA tests.  It has conducted nearly 1,000,000 yDNA tests, hosts over 10,000 registered surname studies, and provides useful support.  No member of our Study has any financial connection with FTDNA.

FTDNA's Y-DNA tests do not have any medical significance and, lacking any custody trail, are irrelevant to paternity cases.  However DNA test results may bring surprises and be disappointing: prospective testers are advised to read section 2.9 of Interpreting DNA Test Results.  Use of test results for Law Enforcement Matching is an emotive issue but FTDNA give each customer the ability to opt in or opt out at their choice, and to change their opting at any time if they so wish.

When FTDNA receives your application they will send you a sample test kit and simple instructions on its use.  On receipt of your two saliva samples they will undertake the relevant analysis, enter your results in their confidential database, compare these results with those of other testers in this database, and advise you of any testers with exact or close matches.  We recommend that you complete FTDNA’s Release Form so you you gain access to the e-mail addresses of these testers, and in indication of how closely you are related to them.  

When your test results are complete FTDNA enable you to download a note on “Understanding your results”.  In addition your Study Administrator will enter your test results in the Results Table for the Study and discuss with you by e-mail their significance and implications. 

If you already have the results of a Y-DNA test with FTDNA and your surname is Irwin (or variant spelling) but you are not a member of this Study you are welcome to e-mail the Study Administrator or to request participation at no additional cost.  

If you already have the results of a Y-DNA test with the Genographic Project and your surname is Irwin (or variant spelling) you can also participate in this Study at no additional cost:  simply log in to your Genographic Project page, go to "What else can I do with my results", click on "Learn more" and follow the instructions. 

If you already have the results of a Y-DNA test with another company and your surname is Irwin (or variant spelling) you are also welcome to participate in this Study, although for full benefits it is desirable to re-test with FTDNA.  For this a discount may be available - please contact

If you already have the results of a Y-DNA test with any company and have a surname quite dissimilar to Irwin but your yDNA signature is a close match with existing testers (as evidenced, for example, by FTDNA "Matches" page showing all or nearly all of your matches are with Irwins), then you are welcome to contact the Study Administrator to request participation in this Study. 


         Relationship                          Match Probability

         2nd cousin or closer:                >99%

         3rd cousin:                                 >90%

         4th cousin:                                 >50%

         5th cousin:                                 >10%

         6th cousin or more distaqnt:  <   2% 

Note that not only must the cousin be relatively close, but he or she must also have taken a Family Finder test.  This test is thus useful for confirming two suspected close cousins are indeed related, and may be useful to a single tester "fishing" for possible unknown cousins, especially those resident in USA, and a growing number of non-Americans are now taking Family Finder tests as well. Incidentally, according to Ancestry’s calculations, the average British person has around 1,570 fourth cousins, 17,300 fifth cousins, and 174,000 sixth cousins.

4. All those interested in genetic genealogy, whether members of this Study or not, are encouraged to join ISOGG, the International Society of Genetic      Genealogists - membership is free.  See

Leaving the Study

You may request to leave FTDNA's project at any time by sending an e-mail to the Study Administrator, or to groups, advising your wish to leave the Irwin Clan Surname Project, or by clicking the relevant "Leave" box on your Project Preferences page.   You may also request to leave this independent Study by sending an e-mail to the Study Administrator., in which case your request will be cmplied with as soon as practicable.