How Many Markers?

The question comes up as to whether it's better to get the 12 marker kit or the 25 marker kit or 37 marker kit or the 59 marker kit.  There are some reasons for choosing 12 or 25 initially. The 25 marker test is going to provide a shorter TMRCA (Time To Most Recent Common Ancestry); in other words your probabilities of matching another will occur within a shorter number of generations. (That is, you will know that there's a 50 percent chance you match someone within 8 generations as opposed to 14, for example). One reason  is, from a practical standpoint, the cost of the test, others are considering what results one would like to get. Remember also that genealogy DNA testing is not an exact science, but another good way, along with a documented paper trail of baseline ancestors, to sort out surnames. The 37 marker test discussion is here

• 12 Markers- $99.00 for 12 marker test (plus S&H) (The cost of the kit for non-group members is higher)
• 25 Markers - $148.00 for 25 marker test (plus S&H) (The cost of the kit for non-group members is higher)
• 12-25 Marker Upgrade- $49 for 12-25 marker upgrade (plus S&H)
• 37 Markers- $189 for 37 marker test (plus S&H)
• 25-37 Marker Upgrade- $49 for 25-37 marker upgrade (plus S&H)
• 12-37 Marker Upgrade $99 for 12-37 marker upgrade (plus S&H)
• 67 Markers - $269 for 67 marker test (plus S&H) (The cost of the kit for non group members is $  )
• 12-67 Marker Upgrade - $189 for 12-67 marker upgrade (plus S&H)
• 25-67 Marker Upgrade -$148 for 25-67 marker upgrade (Plus S&H)
• 37-67 Marker Upgrade - $99 for 37-67 marker upgrade (plus S&H)

After the cost is considered, the next considerations, I believe, are these.

• The number of people in the main family groups that have taken the test to compare against. As a new project progresses, there will be more people to test results against. You might opt to take the 12 marker test and upgrade later if there are some other participants you wish to compare against in greater detail. Why would you want to check for greater detail? Because either you would find that more markers continue to show matches or more markers show mutational differences that were not obvious with only 12. (In some cases, a participant matched on 12 markers but the relationship was completely disproven with 25).
• The amount of paper trail that exists for some baseline ancestors. Some participants will not necessarily be interested in more than 12 markers, but more of a test to see if they match the baselines that are being established.
• How many generations back do you want to compare exact matches AND/OR if there is an exact match or close match on 12 markers, what differences or similarities would 25 markers show? A 25 marker test brings closer the TMRCA (Time to Most Recent Common Ancestry) to a shorter number of generations where there is a match (See http://nitro.biosci.arizona.edu/ftdna/TMRCA.html )

So, let's use some examples:

• 12 marker test-exact match. To find out if the matches are within a shorter number of generations, 2 of the participants could take 25 marker test.
• 12 marker test-one mutation, no other exact matches. Seeking another distant cousin of that 11/12 match to test against to see if the same mutation occurs. 25 marker test against 12/12 with 25 markers could also show additional mutational distinctions disproving a match that might look apparent with 12/12.
• 12 marker test-two mutations, no other exact matches. Seeking a distant cousin of that 10/12 match to test against as well as upgrading when that occurs for finer results to 25 marker would be beneficial.

Therefore, going to recommend this. Starting with the 12 marker test will save money for the group as a whole, and will, I think, encourage more participants in the program to test against. If you want to, initially get the 25 marker test, but if there are no other 25 marker participants, you will not have a base to test against. . If you get the 12 marker test, consider that you may want to upgrade to the 25 markers if you have a 12/12 match with another participant you would like to do a finer match-testing against. This may not occur for a while as the project grows in size.

There is some very good information on the front page, right hand side, of the Family Tree DNA site which is must reading, including this http://www.familytreedna.com/markerschart.html