Genetic Genealogy*

The latest trend in genealogy research is DNA testing. Family historians will pay big bucks to discover what ancestral information their genes hold.  If you've been tested, you might be wondering if other who share your surname have tested.  And you're probably curious about how many long-lost relatives you have, just waiting to be found.

 

DNA Heritage's Ybase provides free search and submission capabilities anyone can use. It doesn't matter what company conducted your DNA test, either. Search the Y-chromosome database by inputting up to 36 Y-chromosome markers. Search results will include exact matches or near misses.

 

You can also search by surname, surname variants and ancestral information. If you'd like to create a record, submit your Y-chromosome genetic markers, surname, information on your direct paternal line and your e-mail address. Once you've completed the submission process, you're given a record identification number and a password. Return to the site any time to edit your record.

 

* Excerpted from Family Tree Magazine, Email Update, January 16,  2003

Interpreting Results: Marker Mutation Rates*
The scientists estimate that Markers mutate, or change, about once every 500 generations, per Marker.  A mutation can occur at any time.  It appears, though there is no scientific proof, that some families have more mutations than others.

 

DNA testing is a powerful tool to be used in conjunction with Family History research.  The foundation of Family History research is the essential framework needed to then evaluate the DNA evidence.  Mutations can then be evaluated as to whether they are mutations, or represent a problem with the Family History research.

 

In evaluating the DNA results, the Marker Mutation rates may provide clues to differentiate between Mutations and Family History research problems.

 

The 5 fastest moving Markers are:  464, 449, 439, 385, and 458

 

Marker 464 is the fastest moving marker, and Marker 458 is the slowest of this group of the fast moving Markers.  The other three Markers are between the fastest, and the slowest of the fast moving Markers.

 

Here is an example of applying this knowledge to analyzing your DNA results in conjunction with Family History research.

 

The two participants match 24/25, and have similar surnames.  Participant A has a well researched and documented tree, and Participant B has a somewhat documented tree.   B has a mutation at Marker 449, which is one of the 5 fastest moving Markers.  The participants do not match any one else in the database.

 

Based in the genealogy evidence, and the DNA evidence and mutation rates, we can conclude that A and B are definitely related.

 

Consider this situation:  The two participants match 10/12, and have identical surnames.  A mutation has occurred on Markers 392 and 393.  Participant A only matches those with his surname.  Participant B matches many people, including others with different surnames.

 

In this example, A and B are probably not related in a genealogical time frame.  It is recommended that they upgrade to the 25 Marker Y DNA test to determine if the mutations hold at 2, or increase.  If the mutations hold at 2, then they are more likely to be related in a genealogical time frame.

 

When your Surname Project has a majority of participants who match 12/12 or 25/25, and then a new participant is found with mutations, you may want to consider the Marker mutation rates in your analysis of the participants' relatedness.

 

* Excerpted from Facts & Genes from Family Tree DNA, January 31, 2003, Volume 2, Issue 1

Additional on Mutation Rates

Family Tree DNA's population geneticist, Dr. Bruce Walsh, has set up a page that explains mutations and predicted times with confidence intervals at:  http://nitro.biosci.arizona.edu/ftdna/TMRCA.htm1

 

In addition, Family Tree DNA expounded on mutational rate as follows:

 

"It is obvious from our observation of 1000's of samples that some markers change or mutate at a faster rate than others. While that actual 'faster rate' has not yet been definitively calculated, not all markers should be treated the same for evaluation purposes.

"The markers in red [refer to "charts page] have shown a faster mutation rate then the average, and therefore these markers are very helpful at splitting lineages into sub sets, or branches, within your family tree.

"Explained another way, if you match exactly on all of the markers except for one or a few of the markers we have determined mutate more quickly, then despite the mutation this mismatch only slightly decreases the probability of two people in your surname group who match 11/12 or even 23/25 of not sharing a recent common ancestor."

Haplogroups

A good place to go to determine your Y-Chromosome haplogroup: http://freepages.genealogy.rootsweb.com/~dgarvey/DNA/RelGenMarkers.htm