Sunday, September 27, 2009
FTDNA v. 23andMe
By Roberta Estes, DNA Explain
Someone asked if the new autosomal testing replaces the traditional Yline and mtdna testing we've been having done within and outside of our projects at Family Tree DNA. The answer is a resounding ABSOLUTELY NOT - THIS DOES NOT REPLACE TRADITIONAL GENEALOGY TESTING!!! Don't think for a minute that it does:) Makes my heart skip a beat to even think that anyone might consider this.
Let's talk about the two types of ancestry testing and what you get with each company (and each type of testing).
Family Tree DNA specializes in testing for genealogy, meaning Yline, mitochondrial and deep ancestry. They provide great products to do this, some that are not offered by others, but also interpretative tools for each individual. Most importantly, they provide surname, haplogroup and geographic projects (and tools) that allow us to group ourselves together, to study our results and to make sense of our personal and group ancestry. Yes, I know that various other companies provide pieces and parts of this too, but FTDNA provides the largest set of tools and the largest data base and that is where all of my projects reside so that is who I'm discussing. Any other company would represent a subset of what is offered by FTDNA.
At 23andMe, you are provided with your haplogroup assignment. If you are male, you get both yline and mtdna. I don't know how they assign the yline haplogroups, but I do know that they do not test your DNA for insertions and deletions. In some cases, tiny bits of your dna drop out, which is called a deletion, and in other cases, a bit of it "cuts in line" and that is called an insertion. 23andMe tests only specific locations using chip technology, which is how they can test so much of your DNA, but it does not allow them the latitude to "look around" for insertions and deletions. When assigning mitochondrial haplogroups, this is critically important as many haplogroup assignments depend on insertions an deletions, so their mitochondrial haplogroup assignments are sometimes incorrect. Mine is incorrect which frustrates me incredibly.
Family Tree DNA on the other hand does a full sequence analysis when you purchase the Full Sequence product (FGS) and they do "look around" giving you a complete picture of your mito DNA including insertions and deletions. Their product is not only more accurate, you also get to match to others who have tested at the HVR1, 2 and full sequence levels and receive their e-mail addresses. Family Tree DNA provides us with the matching feature for results plus notification.
23andMe does not test the normal genealogy markers panels, the STRs, for yline. This means that there are no 12, 25, 37 or 67 marker values reported and these are the genealogy values we all need to determine if we are related to the "Smith line from Surry County, Virginia" as opposed to the "Smith line from Tyrrell County, North Carolina". This was and is the most important part of genetic ancestry testing and you don't get it at 23andMe. Their product offerings are different and can be used in conjunction with these tests, but have nothing to offer in this area.
Please be aware that this is not meant to be critical of either company, only to explain their differences and where both of them fit into the scheme for genealogists and when using each company is appropriate genealogically.
Family Tree DNA provides us with organized projects to compare the genealogical data as well, which is the second half of the genealogy equation, having the tools to do something with those raw results. Bless them, over and over, for this. They have also given us Ysearch, another great tool that everyone can use, meaning not just FTDNA clients, to compare your DNA.
FTDNA clients also receive important tools and information tabs including the haplotree which graphically displays info about your haplogroup, your SNPs (which are not separately reported at 23andMe in a usable fashion), migration routes, haplogroup percents, ancestral origins, and the maps. The mapping feature is often overlooked and that's sad because if people entered their oldest ancestor info and their location, it provides a great deal of "patterning" in terms of migration, especially related to haplogroups and families in Europe, but I am digressing again. I just worked on a haplogroup N1c1 project where the maps were critical to determining where the gentleman's ancestor actually came from.
Not to mention that Family Tree DNA offers their new Traits, the boutique SNP selections, the Personal Reports, upgrades, and probably other things I'm not thinking about. They also provide administrators with tools and the conference for education. These things, except for the Traits, are not offered at 23andMe, and even if they were, the sheer number of people in the Family Tree Data Base who are obviously interested in genealogy provides the perfect environment for the genealogist.
Having said that, the importance of the 23andMe testing, aside from the Health Traits which are great (and worth every penny), but not typically the primary interest of genealogists, is their foray into autosomal testing and making it relevant for genealogists. Because they are using the chip technology that allows them to test half a million locations and store those results, it also makes it doable to measure inheritance segments and translate that into degrees of relationship. Family Tree DNA does not do this today. How well 23andMe can do this remains to be seen, but that is the focus of the Relative Finder project.
Again, because of the sheer number of locations tested, it allows research to correlate the values at certain DNA locations with geographic ancestral locations. This has manifested itself in the percentages of Ethnicity reported by 23andMe. 23andMe and DeCodeMe both report this percentage today for European, African and Asian, but while 23andMe has aggressively priced their products and pursued the genealogy community, DeCodeMe has not and the result is that few use their service and most use 23andMe for wide spectrum (chip) testing. Many in the US are interested in their minority ancestry, whatever that happens to be. For me, minority means Native and African. 23andMe (and DeCodeMe) both tell me IF I carry that ancestry, by percent, but not where. Based on comparisons with some of the early testing companies (DNAPrint) they are much much more accurate in their assessment than the earlier tests that measured only a few locations. However, in order to find that elusive minority ancestor, I need to return to traditional genealogy testing, yline and mtdna, with the features of matching to people, within and outside of projects, with e-mail addresses to contact. To do this, I encourage people to construct their own DNA Personal Pedigree Chart. You can see an article about how to do this at this link or I can send it to you as a pdf file. Be sure to check existing surname projects to see if someone from your distant lines has already tested. To do this, go to FTDNA and enter the surname in the search box in the upper right hand corner.
So when do you use which company?
For genealogy, always test your yline and mtdna using the traditional tools, join the projects at FTDNA, compare your genealogical results to others, and learn as much as you can using these tools. They are very specific and can tell you whether you are related to a particular family or person via a particular line, meaning the paternal or maternal. You also receive your deep ancestry results which are just genealogy back further in time and without last names. Deep Clade testing allows you to become very granular in terms of the timeframe of when your ancestors were where. With the advances we've made with SNP information in the past few months and years, it won't be long before the SNP timeframe meets the genealogy timeframe and in some cases, we're connecting the dots very successfully today.
The 23andMe tests are more of the "graduate class" for genealogists, aside from their Health Traits, of course. I can't imagine a genealogist ever testing at 23andMe and NOT testing their yline, mtdna and comparing them to others at Family Tree DNA in their projects. Many of us want to answer questions that yline and mtdna just haven't been able to answer for us, and that's why we've turned to autosomal testing. Of course, there is also a curiosity factor, pure and simple, in terms of ethnicity and also in terms of the Health traits that may attract some folks. Many will purchase the test for the Health Traits alone whether they are interested in genealogy or not. But if they are serious genealogists, they will use the two types of testing together to achieve our ultimate goals of unraveling our ancestors.
Genetics for genealogy is truly the best tool we've ever had as genealogists, and it gets better every day.