Group 25 & 28 - Descendants of Sheriff John Carpenter-1736
Born abt 1582 of, Horsham, Sussex, England - Died 9 Aug 1671 in Horsham

Group 25 & 28 – An Introduction

The Carpenter Cousins Project has Group 25 and Group 28 as descendants of Sheriff John Carpenter-91736 but through different wives. See image below.

While both Groups 25 & 28 have a common genealogical ancestor they have very different genetic descendants. This brief will provide the basics of how different Group 25 and Group 28 are genetically different via Y-DNA testing.

Please remember that while these two groups are connected genealogically, they are clearly very different genetically.

Can this be confusing? Yes, many of these genealogical and genetic concepts can be confusing. But, there is a certain logic and symmetry when one does understand what is being seen. Hopefully my basic presentation that follows will be clear enough to understand.

In traditional Genealogy one documents the facts of person A connecting to person B, to person C and so forth back into time. Genealogy is based on the facts of birth, marriage death and the connectiveness of marriages to confirm relationships. All is very logical and predictable as long as you have the documentation proving what you claim.

If one can not connect them in some manner with some sort of documentation then we are left with speculations and educated guesses. This is unless we find another way of documenting family members using genetic DNA testing. And specifically using Y-Chromosomal (Y-DNA) genetic tests which has proven very successful in surname studies.

In Genetic Genealogy we have the hybrid of genealogical with DNA testing to help break down genealogical road blocks and to show genetically related individuals who have been DNA tested. This is done via triangulation. Simply person A matches person B genetically (the base of the triangle) and when they compare their genealogies they find the most recent common ancestor (MRCA) which forms the peak of the triangle. It is all very simple to show person A and person B are connected genetically and genealogically.

It is all very simple until you have person A matching person B genetically but NOT genealogically. There are books written on all of the above including things to do when the “very simple” is no longer simple.

In the case of Groups 25 & 28, we have Group A (aka Group 25) matching Group B (aka Group 28) genealogically but NOT genetically. In traditional genetic genealogy that is where we would stop. These two groups do NOT have the same common genetic ancestor.

While genealogical studies are fraught with errors, sometimes there is enough information to "believe" but not prove the genealogical relationship. And while Group 25 "can not be proved," it is still believed to be related genealogically to Group 28. Again normally, we would assume the genealogy is wrong. Except in case of a "NPE" or non-paternal event (aka non-paternity event). See more on this on the ISOGG (International Society of Genetic Genealogy Wiki regarding "Non-paternity event(s)."

Briefly, a NPE is where there is a formal or informal adoption of DNA into a genealogical lineage.

The most common NPE I and others have identified is a widow with a young male child that remarries. The child bonds with the stepfather and assumes his surname.

Historically, before the modern codified and more documented government, a male wishing to marry a widow with children had two choices. Either accept or reject the children of the widow. Rejecting them meant they would be farmed out to relatives and under a worse case situation a public work house or orphanage. On occasion, once the new family was established, some of the widow's children maybe allowed to reside temporarily. If the potential new husband accepted the children then he became the defacto father according to the community. He then took responsibility to raise them properly as if they were his own blood.

One technique is a Y-DNA surname study is to compare Y-DNA marker values. If this numerical value pattern is exact then they match exactly (aka genetic distance of zero "0") at the number of common markers tested. If they match closely then that is defined. For example: a 36/37 marker match is a mismatch of one marker of a value of one numerical value - aka a genetic distance of one.

Can it get more complicated? Yes. But in this brief, the example is adequate to present the idea of difference. These numerical values form a genetic profile or genetic fingerprint. Another way of looking at, is that their Y-DNA marker value are their genetic ID or genetic identification number. And those males (who carry the Y-Chromosome) in the same family have virtually the same Y-DNA as their biological father and so forth back into history. This is why Y-DNA is excellent for surname studies.

By collecting the same or very similar genetic profiles with the same or similar surnames using Y-DNA testing then you start a genetic group. These genetic surname groups are based on Y chromosome Short Tandem Repeats (Y-STRs) that form a genetic profile or genetic fingerprint. This is done by using the numerical value indicating the number of protein repeats of each specific DNA Y-Chromosomal Segment – aka DYS – marker.

There are 7 markers showing seven one digit differences representling a genetic distance of 7 out of 25 markers. Then there is a single marker (DYS458) that has a three step (numerical) difference. This one DYS458 marker contributes another genetic distance of 3. Total genetic distance is now 10 out of 25 markers. This is like a 15/25 marker match which is clearly NOT closely related genetically. Other Y-DNA markers 26 up to 67 markers tested are not shown in this example, indicate even more differences.

Those 25 Y-DNA markers first cited are on the next image from Table 1 of the Carpenter Cousins Y-DNA Project showing Family Tree DNA marker set 1 to 25. Those who test the 26 to 37 marker sets (Table 2) are indicated by the red block (with the greater than symbol) at the end of that line. Grey blocks indicate mutations to the group mean.

Another important item to be aware of is the number of Y-DNA markers tested. The more Y-DNA markers one compares, the better. This is because it increases the probability of the genetic relatedness.

Group 25 and 28 are uniquely different in their genetic profile or fingerprint compared to each other and other Groups in the Carpenter Cousins Y-DNA Project.

While Groups 25 & Group 28 claim a genealogical relationship (see image below), they are clearly NOT genetically related.

This next image is adapted from the The Carpenter Cousins Y-DNA Project lineage page. This image shows the believed relationship between Group 25 and Group 28 genealogically.

It is important that DNA Projects show their work in triangulation of both the genetic DNA matches and how lineages fit together genealogically. This report and others like it from the Carpenter Cousins Project tries to show this work. The Carpenter Cousins Y-DNA Project provides genetic tables by groups and a separate, but group related, lineage page showing the ancestry of those Y-DNA tested. Group 25 and Group 28 need much more work genealogically and with more Y-DNA testing to better understand why the genetic parts are so different to the genealogical whole.

This brief along with the rest of the effort is to help educate and encourage those matching Group 25 and Group 28 either genetically or genealogically. Why? Because if you are related (genetically or genealogically) in any way, please be part of the solution! Help share your genealogy and please participate in Y-DNA testing!

Regarding Genetic Genealogy there are many very well done books and many web pages that show how the genetics match up with the genealogy. The following links will provide a basic guide on DNA testing and a follow up on two advanced DNA tests. Please remember that there are different DNA tests and that each DNA test is a tool with their own plusses and minuses. Again, the following links maybe helpful.


If you have any questions about the Carpenter Cousins Project (genealogical support) and the Carpenter Cousins Y-DNA Project, please see: The Carpenter Cousins Project webpage

John R. Carpenter
La Mesa, CA USA

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