MyHeritage.com

As I continue to research my ancestry through DNA, using various tools and services, and gaining experience and perspective, my views of DNA services evolve. These are my thoughts about MyHeritageDNA, at this time, nearly three years into my DNA research. (Note: though I use the name MyHeritageDNA to distinguish the DNA matching service from the record searching service, both are accessed through the address myheritage.com, and the services are closely linked.) (Another note: MyHeritage is an Israeli company.)

Pros:

1) MyHeritageDNA has a large number of DNA contributors. Even though they are relative (no pun intended) newcomers to DNA analysis, they have allowed people to submit DNA analysis files from other services in order to quickly grow their contributors.

2) MyHeritage allows contributors to build family trees linked to their DNA, essential for exploring your relationship. While trees are generally smaller than what is available at Ancestry, in most cases you have full access to the whole tree. (Ancestry limits access to 5 generations, 23andMe doesn't have trees, GEDMatch does allow trees, though I find few contributors have them.) 

3) MyHeritage (currently) allows the use of third party tools that gather family tree data and DNA match data for exploration offline.

4) MyHeritage's list of common matches (ICW) also shows the relationship between the match and the ICW. This can be helpful in focussing your search for a relationship, or for selecting closer relationships to investigate. (For instance if you know that one of your ICW is a great aunt to the match you're reviewing, you can limit your investigation to the great-aunt's ancestor tree.)

5) MyHeritage has a closely linked (for pay) records collection, though I have never used it and can't comment on how it compares to other records services.

6) MyHeritage also owns one of the premier genealogy products, Legacy Family Tree, which is my genealogy software. While I know that Legacy has features that facilitate genealogy research, I don't use these features myself.

7) MyHeritage allows you to download your DNA analysis file, as well as match files. The former allows users to submit their DNA analysis to matching services like GEDMatch (I'm not necessarily recommending you do that). The latter allows users to keep track of DNA research offline using, for example, tools like Genome Mate Pro.

8) MyHeritage shows detailed information on shared DNA segments and which matches "triangulate", a much higher level of confidence of a family connection than the ICW relationships. (Ancestry shows only ICW. 23andMe shows both ICW and triangulation. GEDMatch shows only ICW, though I'm not sure what they offer to paid subscribers.)

9) Has an interesting DNA research tool:. DNA Clusters shows groups of related DNA matches. It used only about 100 of the several thousand matches, but as I identify more of my matches it is showing some promise.

10) MyHeritage ethnicity estimates seem as accurate as those from other services. At least compared to my own family history estimates.

Cons:

1) MyHeritage shows matches down to 8cM. Ancestry recently raised their minimum to 8cM as well. 23andMe seems to show down to about 7cM. For those, like me, with well-developed family trees, smaller amounts of shared DNA are needed to extend our histories. Smaller DNA matches are admittedly much less certain, but I have made several 6cM matches (at Ancestry before they changed their minimum match criterion) so far and would prefer to have access to these possible more distant matches.

2) MyHeritage flags are not very useful. I can neither set a flag (or star, as in Ancestry or 23andMe) nor read an annotation (as in Ancestry) to indicate that I have already connected a match to my family. In MyHeritage I have to open the attached note to know the status of this match.

3) For whatever reasons, I have identified far fewer matches through MyHeritage than through 23andMe or Ancestry. I assume this is mostly the relative popularity of this service.

My Genetic Genealogy: Pros and Cons of Too Many Matches

I've been working with DNA kits on 23andMe, MyHeritage, and AncestryDNA. One of my first observations was, after beginning with 23andMe and seeing about 1000 DNA matches, that MyHeritage's 3,ooo matches was ridiculous. Who will ever have time to go through and try to link 3,000 matches! 23andMe is now providing about 1200 matches and MyHeritage is now about 8000. Really? But now I've crunched some numbers and am having second thoughts.

The Beginning

Browsing through matches on 23andMe, I started exploring a not-too-distant match for my father, 0.95% shared DNA, about 70cM, somewhere near average for a 3rd cousin. Except that Dad is in his early nineties and the match was middle-aged, so the relationship is more likely to be a 2nd cousin twice removed. This indicates a common ancestor of Dad's great-grandparents who immigrated to the United States.

The Genealogies

Dad's match was able to provide me with his family genealogy back to the early 1800s in Ireland. There was no intersection with my tree, which also geos back this far. Knowing that there is a connection, through the DNA match, the genealogies indicated that the family connection would have to be one or more generations earlier than the 0.8%  shared DNA suggested. Something's not right.

Different Relatives in Common

Comparing notes, we realized that Dennis's list of Relatives in Common (persons that were DNA matches to both him and to Dad) was different from Dad's list. I've noticed this with others, but hadn't delved into the explanation. So, FYI. Both lists were about 35 persons long, but only about 5 persons were the same on both lists. I asked 23andMe for an explanation.

The Relatives in Common list is created by taking your list of DNA matches - about 1200 at 23andMe - and selecting from them those that also share at least 5cM of DNA with the match you are comparing to. To make this less abstract. Suppose Dad's match is Dennis. [In what follows, Dennis and Keith are made-up names.] Dennis has a list of 1200 DNA matches, one of which is Dad. When he clicks on Dad, he is presented with a list of about 35 Relatives in Common. This list is created by taking Dennis's 1200 matches and selecting those who share at least 5cM (this is a VERY small piece of DNA) with Dad. If I look at Dad's list of all DNA matches, the very last one shares 0.27% (about 20cM). Dad's list of Relatives in Common must be from his list of matches, all of which share at least 20cM of DNA with him. The only persons who who show up on both Dennis's and Dad's lists share at least 20cM of DNA with both of them (though I don't know exactly Dennis's threshold), only about 5 persons. Note that both lists are valid, but this explains why they are different.

Cousin Keith

Dennis mentioned that his first cousin, Keith, was on his Relatives in Common, though it was not on Dad's. It turns out that Keith shares about 0.15% DNA with Dad, so doesn't make Dad's list of 1200 matches, so doesn't show up on Dad's version of the Relatives in Common. The second thing to note is that two first cousins should share about the same amount of DNA with Dad, while Dennis and Keith share 0.95% and 0.15%, respectively. This is a reminder that there can be large variations in inherited DNA. One possibility is that Dennis and Keith are related to Dad through different relatives, but further research showed this to be nearly impossible. Comparing to the genealogy research we were studying earlier, though, Keith's shared DNA indicates a common ancestor one or two generations further back than our immigrant ancestor, which could fit our observations better. My current hypothesis is that cousin Keith shares a more normal amount of DNA for the relationship with Dad, while Dennis inherited an unusually long strand of DNA.

What Does This Mean?

In this case, I seem to have gotten lucky that Dennis had an unusually long inherited strand of DNA that moved him above Dad's match threshold of about 0.27%. If not, I would not have seen this connection to investigate. This is disappointing. Much of my known genealogy ends with immigrant ancestors who are great-grandparents to my parents (whose DNA I am working with). My findings with cousins Dennis and Keith leads me to believe it is unlikely I will find connections to earlier ancestors in their countries of origin through 23andMe. Remember that my initial thought had been 1200 DNA matches is more than enough to work with. Now I see that it is not enough for the pre-immigration connections I eventually hope to make.

Not Quite That Bad

So far, in two of my ancestral lines, I was able to connect with many matches through 23andMe whose common ancestor was a pre-immigration family. Fortunately, there are older participants from these "clans" whose relationship to Mom/Dad were 3rd cousin once removed. The average shared DNA for 3rd cousins once removed is about 0.4%, so above the 0.27% threshold for 23andMe matches. But it is important to seek connections with older matches (say, 60 and up). It remains to be seen whether this population will decrease, from natural causes, or increase as more people get their family elders tested.

What About Other DNA Services?

AncestryDNA: I don't know the numbers for Ancestry. I haven't found a way to harvest their matches, Ancestry does allow downloads of this information, and I ran out of patience scrolling endlessly through who knows how many matches to find the end.

MyHeritage identifies about 8,000 DNA matches, down to about 8cM. Perhaps overwhelming. Perhaps absurd. But it does seem to allow the possibility of connecting back further in time. Identifying the ancestral line going so far back from smaller DNA segments will, however, require lots of luck and lots of work.

[I've assumed a very simple relationship between shared DNA and relationship, while in reality, it is not simple. A simple relationship is easier to understand, and I think allows me to make my point.]