Monday, September 2, 2013

Using the Chromosome Browser in ftDNA

Here is a quick tutorial on how to use the Chromosome Browser in ftDNA to determine how you match someone on your Family Finder test.

Determining how you match someone is important when you are trying to figure out if you share a common ancestor with someone.

In order to determine if you share a common ancestor with someone, you should first be deemed a match with them from ftDNA. Once you are designated as a match, then you can use the Chromosome Browser to determine HOW you match them.

Go into your ftDNA account, click on the Family Finder button, then click on the chromosome browser link.

Chromosome Browser Screenshot ftDNA

Once you are in the chromosome browser, click the drop down box and then select “name.”

Chromosome Browser Screenshot 2 ftDNA

Then type in the name you are looking for into the box and click the “Find” button. (Don’t hit “enter” or it won’t work). Click on the little box beside their name to add them to the compare list. 
In this example, I am currently logged in to my cousin's account. If I want to see how she compares to me, then I can simply type my name into the Find box. 

Chromosome Browser Screenshot 3 ftDNA

You will see your match light up in the chromosomes on the right. Then click the “Download to excel (CSV Format)” Link at the top to export to excel. Open the downloaded CSV file in Excel to see the chromosomes that you match to that person on. 

You are probably wondering how or why this tool is important. Let's say for example you start emailing with one of your matches - we will call you Person "A" and your match Person "B" - and they ask you if you are a match to a 3rd person "C." If you (Person "A") match to Person "B" and Person "B" matches to Person "C" and you (Person "A") also match to Person "C," then the three of you might have a common ancestor. This is called the "Triangulation" process. 

That all 3 people are a match to each other is not the only requirement though. All 3 people must match each other on the same segment of the same chromosome of DNA. And the only way to know this for sure is if all 3 people share their chromosome data with each other - Chromosome data that is downloaded from their chromosome browser. 

So really, it's not just one name that will be loaded into the chromosome browser - but two. 

So next time one of your matches sends you a strange email asking you if you are a match to a 3rd person (or 4th, 5th, and so on), don't delete it. Just follow the instructions I provided above and send the data to them and I promise it will help you get through your DNA results and find those elusive ancestors! 

Kelly Wheaton has published some excellent tutorials on genetic genealogy. Please give her site a look. I have included the link to Tutorial # 9: working with your matches

No comments:

Post a Comment