How to read the results charts, and other things
One of the problems with doing something for ten years is that you forget that the rest of the world hasn't had your experiences. So you (I) often forget how to explain things to others. Such is sometimes the case with the results from the DNA tests. There is so much data, and there are so many ways to analyze the data that the meaning is sometimes lost in the facts.
In this article, I'm going to walk through the different information available to us, starting from the first information sent to us from FamilyTreeDNA when our test results come in, and continuing through the other information at our personal pages at the FamilyTreeDNA website, the standard and our customized results table, and some of the other information that results from all this.
This is likely going to be a long article, but I'll try to structure it so it is easier to follow ... and to skip over some that you may not care about. I'll also try to emphasize what you should do with the information. The box to the right lists the actions you should be taking and links to the section on how to do it.
FamilyTreeDNA: Your results are in!
When your test results come back from the lab, FamilyTreeDNA sends you a notice with a link to your personal page. Hopefully you still have your log-in information they set you. (If not, there is a "Forgot Your Password?" link under the Log-In form). So your first real step in using your results is to go to your page and log-in.
Just below the navigation bar (Home, MyAccount, etc) is the Interactive Tour box. If this is your first time to your page, or it has been a while, you should go through the tour to get acquainted with your page and the resources available there. Each step in the tour has a description and usually a "Show Me" link that pops up a pointer to the feature they are talking about. The tour is about your personal web page, settings, and options mostly. It is to help you find your way around, and to encourage you to keep your information up to date. It is a little light on using your test results, which I'll emphasize in this article. I've highlighted some of the administrative information in boxes to the right in this article.
Action: When you get your notice that the results are in, log into your personal page at FamilyTreeDNA.com and get acquainted with how it works.
Who do you match?
The y-chromosome test tells you whether you and another person share a common ancestor or not. So the first place you want to go after you get acquainted with what is on your personal page is the list of matches. In the blue navigation bar at the top of the page (Home, MyAccount, etc.), put your mouse over Y-DNA and select the second item “Matches”. This page remembers the display choices you made on your previous visit, so I'll tell you the selections I suggest, although these may already be set for you.
Your first time through, for "Show Matches for:" choose "Hadley". This will show you only matches for those who are part of our project. You'll want to run the report with the entire database eventually, but to start with, look within our project only.
The next box selects which of your test results to examine. It should default to the number of markers in your test. So if you signed up for the 37-marker test, it should say 37. If you signed up for 12, it should show 12. If there are no matches with the number you enter, it will automatically try again with fewer markers until it finds some matches, if there are any. Because different participants have ordered different tests, some very important matches may not show up using the higher number of markers.
Assuming there are matches to display, you will be presented with a list of people who "match" your results, sorted in order of best matches first, followed by those who may not be exact matches but who are close enough to be listed. The left column lists the number of "Steps" that separate you and your matches. 0 means that you match exactly on the number of markers you selected to display. Other numbers represent the statistical distance between you and those listed. These steps take into account which markers didn't match. This is important because some markers are more prone to "mutation" (a.k.a. change) over time so a mismatch is less significant. Think of it as just a number that tells you how close a match is. For those within the Hadley Project, 0 steps means that you very likely share a common ancestor. But, fortunately there is a more scientific way of understand the steps.
To the right of the name of the person who matches you is a column of symbols. The assumption is that you went through the interactive tour and have read all the instructions, so you know what the orange one means. (Yeah, right!). If you want to understand how closely you match someone, click on the orange TiP icon. I have no idea what TiP stands for, and the HELP page doesn't tell you, although it does tell you what it means. The first time you use it, I suggest you click on "Page Help" and read about it.
The chart presented tells you the probability that you and the other person share a common ancestor within the specified number of generations. I will use myself and co-administrator Jim Hadley in the examples in this section. Jim and I are two steps distant in the 37 marker test. The TiP chart initially says that there is a 72% chance that we share a common ancestor within 8 generations and a 91% chance that we share a common ancestor within twelve generations. These probabilities are based on many studies about how each marker changes over time.
For comparison, two people with 0 Steps separation on the 37 marker test have a 97% chance of a common ancestor within 8 generations and 99% chance within 12 generations.
Continuing with the TiP for Jim and me, below the initial table is a heading, "Refine your results with paper trail input". If you have reliable conventional research that you'd like considered in the probability calculations, you can plug it in here. As it warns, if you are not sure of your information, leave the setting at 1. In our case, Jim and I have information that we both believe is accurate. We are 7th cousins, so we could plug in 8, but to be conservative, I plugged in 7. This changed the TiP calculations to say there is only a 39% chance that we have a common ancestor within 8 generations, and an 80% chance that the common ancestor is within 12 generations.
Frankly, I don't understand this, especially when we are both very confident that we do share a common ancestor within 8 generations. I would expect the numbers to go the opposite direction. I need to do more reading on this topic. But try it out for yourself anyway. For my purposes, I find the initial chart much more usefull, and in my case accurate.
What family group do you fit with?
One of the major goals of our project is to identify the DNA patterns for the various Hadley, Headley, etc. families and help members of each line confirm where they belong. To do this, project administrators can identify separate groups within the project and associate individual participants with these groups. So, assuming you have sent me your ancestry information and your test results match the group where you believe you belong, I go to a page in the Project Administrator's Tools section and assign people to appropriate groups. I've written more about the groups in the article on the results table.
Problem: Because of the privacy rules originally established when we started, some changes in the information provided by FamilyTreeDNA on your personal pages, and how the results charts are generated, it is not easy to relate your list of matches and the groups. I'll do a separate article to propose some changes to fix this. Frankly, I didn't notice the problem until I started writing this article. (sigh)
If we have communicated before your results came in, when they do, I'll take a look and be able to tell if the results put you in the group where you thought you fit. If you are totally lost, or even just a bit confused about what the results mean, email me and I'll take a look at your results and offer some guidance. If you haven't already sent me your ancestry information, I will likely start with a request for this.
There are three possible outcomes from looking into which group your DNA test shows you:
- You fit into the group you expected based on your conventional research.
- You fit into a different group than you expected.
- You don't fit into any group.
That last scenario, that you don't fit into any group, is the most complex and the one with the most suggested actions. To simplify this article, which is already getting too long and complicated to follow, I've added a separate article on this, What if I don't fit into any known group?.
If your results confirm your conventional research, you likely consider this great news. It definitely shakes things up when they don't. So if you are in this situation, your next actions are “standard operating procedure”: continue your research to improve the knowledge of each generation, improve the quality of the sources for the information you have, and most importantly, don't forget to interview every living relative you have. They won't be here forever.
If your results connect you with a group other than what you thought, your challenge is to figure out how you fit. Carefully examine the information you have collected that indicated you fit in somewhere else and find the error. All it takes is one wrong parent and you are off down the wrong path. I don't know any way to do this than examining every piece of information you have, starting with yourself and working one generation at a time.
Once you have your results, it is also a good time to consider whether additional DNA testing would help your research. How many markers have you had tested? Would checking more markers improve your results? If you have tested fewer than 37, my opinion is a definite yes. I was hoping some who have had the 67 marker test would send me an article on how those additional markers helped them. Alas, none were sent.
Many of the participants in our project have used the MtDNA and other tests. I'd love to have an article from one of them to pass on how they have used these to help their research.