Pratley DNA Study
In an attempt to bridge the gap between the 1600s and the 1700s which has
been left by the missing baptism register, and determine how all the various
branches of the Pratley family are related, I've set up a DNA project with
FamilyTreeDNA. If we can get as
many male Pratleys as possible to participate, we should be able to build up a
picture of how each line descends from William Spratley.
So if you are (or know of!) a male Pratley, and are interested in taking
part in this project, please
get in touch to discuss
submitting a test kit. The results will remain completely anonymous - only you
and I will know which set of results are yours. The cost of a test kit is
around £85, though I will of course contribute to this.
In order to reduce the number of test kits (and save a bit of money!), only
one representative from each family is needed. So if your brother/father has
already taken part, you don't need to as well.
Hopefully the technology of the 21st century will help to solve the puzzle
of the 17th century!
Results so far: The raw DNA data
The raw data that has been gathered so far can be seen here on FamilyTreeDNA's site.
The results in the red "Main Pratley branch" section form the backbone of the results.
They differ from each other by only a handful of mutations, which not only shows that
they are related within the last 20 or so generations, but more importantly the
differences give an indication of how the ancestors of the testers are connected.
A few notes on the data in this section:
- Kit IN17693 comes from one of the few branches of the Pratleys to
spontaneously appear outside of Oxfordshire in the 1700s, so it's good to have
confirmation through DNA that this branch did indeed have the same origins
as all other Pratleys.
- A few markers have independently mutated in the same way in different
branches, which initially caused possibly ambiguity of interpretation of the
relationship between test kits - in particular, DYS570 changed from 22 to 21
in branches where DYS607 is 14 and also where it is 13, so either DYS570 or
DYS607 could have been the earlier common mutation. However, increasing
the number of tested markers led to DYS712 showing the same grouping as
DYS607, implying that the DYS607 change between 14 and 13 happened first.
The results in the pink "Potters Hill Lodge Pratley branch" section don't
match the main body of the results, so this branch of the family must have had a
female Pratley ancestor some time before the common ancestor of the two testers.
The results in the beige "Joseph Guy b.1812 descendants" section have a couple of
results which match the main body of the results, and so show that Joseph Guy's
father was indeed a Pratley, presumably Joseph Pratley as his mother had stated. Of
the two Joseph Pratleys of the right age from the right place, one descends from the
Potters Hill Lodge Pratleys, and so would have had a different Y-DNA signature (see
above). So it seems likely that the other Joseph Pratley, born 1794 to Michael
Pratley, was Joseph Guy's father.
(The remainder of the results don't match the main set of results, so had a
female Pratley ancestor in the past, but more tests are needed to determine when
this might have been.)
Results so far: Applying the DNA data to the known branches
Main Pratley branch (including Joseph Guy branch)
At the top of the graph is the tree of mutations from the proposed
"original" Pratley markers. At the bottom of the graph are the known
ancestors of the testers, based on the paper-based research. The boxes
show which testers have which mutations, and so allows us to overlay the
ancestry of the testers onto the shape of the tree of mutations.
Some points of interest:
- The test kits delineated by a dashed box have identical markers
(despite not having a common ancestor since at least the early 1700s), and all
other test kits each vary from these marker values by just a handful of
differences, so it is currently being assumed that this set of markers
are those of the earliest common Pratley ancestor.
- It's reassuring to see that, where the ancestral relationships of
the testers (in the bottom half of the diagram) is known, the shapes of the
trees of mutations (top half of the diagram) clearly map
to the shapes of the ancestral relationships.
- The four kits on the left seem to be more closely related to each
other than to other Pratley branches.

"Potters Hill Lodge" Pratley branch
We have two results from the Pratley branch that descends from
John Pratley of Potters Hill Lodge. Again, the graph shows the tree of mutations at the top, and the known
ancestry of the two testers at the bottom, with boxes to show how the top
half maps to the bottom.
