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