Pennington DNA Study Phase II
By the DNA Research Committee
March 9, 2002
The DNA committee is very pleased with the participation of PRA members in the Y-chromosome DNA study so far. By our estimation 19 PRA Family Groups should ideally have taken part in the first round, and 13 Groups followed through. At this time we are issuing a specific challenge to members and Group Leaders of Groups 1, 2, 3, 16, 23 and 32 to step up to the plate.
Why should you do this, particularly if you have a good paper trail back to, say, 1645?
You may think that joining this study can’t help you extend it. But the way we see it is that in the near future more British Penningtons will find out about our study and get tested. If we know that your sequence is found in high numbers in a certain part of the UK, it could provide the crucial clue for the jump over the pond!
Now lets see how your participation might help other “cousins” in the PRA. For those who know their line back to about 1800, a match of their Y-chromosome signature with yours will give them a tremendous boost of informationundefinedall because of your participation. Those who know only about their grandfather will have a quick-and-dirty way of finding out which group is relevant to their quest for knowledge of their ancestors.
The founders of the PRA back in the 60’s always thought that the number of groups would ultimately dwindle to a smaller number as the lineages are pieced together. If some groups are not tested, and don’t discover where they fit in genetically, we will be perpetuating artificial divisions that were never intended to be permanent. Testing is not costly if several members of a Group collect money to support one volunteer.
Note: Click here to participate in the DNA Study.
Why we need more cheek cells.
The first round of tests for the DNA study yielded some interesting results, but they tell us little about the overall structure of the Pennington family, primarily because we have too few participants.
There are now 120 family associations like ours that have embarked on DNA studies!
Let's assume we had 100 participants, like the Graves family DNA study. In that case, what would we expect if there was only one original Mr. Pennington from whom we are all descended? What we would see is a large group of, say, 50 individuals, all with the same 12/12 matches in their Y chromosome sequence. The diagram plotting this group of 100 would look like a star, with maybe 30 or more individuals arranged around the main group of 50. But these sub groups should be only one mutation away (11/12). There will be perhaps 20 or more individuals who don't fit with the main sequence or its one-mutation satellites. These individual sequences probably would be explained by the term “non-paternity event”, which could have occurred at any time in the past 1000 years or so.
However most families and surname studies in the real world do not fit this pattern. What is found is that 3-7 individuals, a long time ago, adopted the surname, and so we see 3-7 clear lines of descent in the Y-chromosome DNA, and a network of one-step mutations from these multiple signatures. So far our study shows this pattern. Additional participants will settle the issue. Who knows, one day we might identify the DNA signature of the Muncaster line!
Science isn’t prone to moss. There’s always progress.
Another recent development has been the addition of nine more markers to refine the Y-chromosome test. Many individuals have been getting 12/12 matches with individuals of the same surname. That is, all twelve Y-chromosome markers match those of another individual. This suggests that those people are related probably within 14 generations. But a 21-marker test allows us to narrow the time line to about 8 generations.
The Research Group has received volunteer funds for additional testing of six of the 13 Family Groups that appear related thus far. The results have just now become available and will be posted later.
Some other participants were left with the feeling that their Group might not be homogenous, that perhaps the single Y-chromosome analysis done so far isn’t representative of the whole Group. They want to obtain additional representatives of their Group to make sure that their sequence truly represents them. The committee encourages this refinement.
Our family, and the family of everyone.
In order to place all of this in perspective, it has been widely reported that the sequencing of the Human Genome has revealed that all humans are genetically at least 99.8% identical. We are a young species and we probably all share a common ancestor about 150,000 years ago. So we really are “the family of man”. Indeed 75,000 years or just 3000 generations ago it is estimated that there were only 10,000 people in Africa who then colonized the rest of the world and now there are 6 billion of us!
It is the remaining 0.2% our DNA that allows the population to be placed into lineages. The study of mutations on the Y-chromosome (or for direct female lines the study of Mitochondrial DNA) will never replace traditional paper-trail genealogy, but it has already become a useful tool to have in the box. Remember, we can only go back so far with a paper trail!
Our understanding of genealogy by genetics is advancing very quickly. There is now a “family tree of all mankind” based on about 150 slowly occurring mutations in the Y-chromosome. This suggests that 99% of all Europeans descend from ten lineages (which really means that ten men had progeny whose descendants made it to the present day). Actually, 95% of all men of European descent fit into just five of these lineages. Fitting into one or another of these five lineages can suggest whether one originates from the indigenous population of, say, the UK, or from one of the invading populations, such as the Norse. Thus, using this technology we can find out not only how closely we are related to someone of the same surname, but we can also get a glimpse of the big picture, and see where our line fits in the grand sweep of history. I joke with a member of the PRA who calls me “cousin”. My Y-chromosome result shows that I am indeed his cousinundefinedbut our families share a common ancestor about 40,000 years ago!
The DNA Committee urges you to participate in this study because it will increase the sum of our knowledge of our greater Pennington family. We encourage you as individuals and as Family Groups to make the investment that 13 public spirited Penningtons have already made. When you do, our information will be much more useful and informative.
Copyright 3/09/02 Nick Penington