Media Starts to Gets Home DNA Testing for Ancestry Right -- Thank God!

Kristen V. Brown is back with an excellent piece for Bloomberg, on home DNA testing, that is remarkably astute for a piece in the popular media.  

It confirms much of what readers of this blog have seen posted here repeatedly.  It's so good, it's worth quoting at length:

DNA is great at identifying familial relationships like parents, grandparents, aunts, uncles and even second and third cousins. Beyond that, it gets fuzzy.

The genes that make you a superfast runner or that identify you as Irish are less well-studied. The accuracy of any one test depends on the data your DNA is being compared to. One 2009 journal article said consumer DNA tests were akin to horoscopes exploiting the human tendency to hunt for patterns in meaningless data.

So what does it mean when a test says I’m 25 percent Irish?

It’s a misconception that these tests can tell you where your DNA was in the past. 

If a test tells you that you’re 25 percent Irish, what it actually means is that you are genetically similar to other people who are a part of the reference data set of Irish DNA that the company has collected. 

Because each company uses a different algorithm and data set, your results may vary based on which company you use. 

In other words: Take all this with one very large pinch of salt!

Meanwhile, in Slate, appeared another excellent piece by John Edward Terrell.  Here's the quote for you to read for yourself:

Whatever the motivations, the current popularity of commercial genetic profiling worries me for two reasons. One is that these companies may be promising results they can’t actually deliver. 

The notion, for example, that our genes can be used to trace our personal ancestry far back into the past—say, to Genghis Khan, the Emperor Charlemagne, or one of the pharaohs of ancient Egypt—makes little statistical sense. You may disagree, but to me this comes across as selling something more akin to snake oil than science.

What worries me most, however, is that companies offering personal genetic testing customarily seem to report back to those sending along a sample of their spit that they are a mix of different “ethnicities.” This is more than simply statistical nonsense.

We are happy that the mainstream media is finally getting it right, instead of publishing starry eyed pop-sci nonsense about DNA tests.

Don't ever forget: if you come from Central Europe (France, Germany, Italy, or nearby countries), or if you come from a country where there are simply insufficient samples (much of the rest of the world), these DNA tests will wipe your heritage off the map, by telling you that you are something else.  Basically, they're most accurate at the Continental level, unless you happen to come from an island in Europe with massive amounts of people getting tested, i.e., the U.K.

DNA Testing for Heritage and Ancestry Is, Simply Put, Inaccurate

You go to take a cholesterol test, and your doctor, very thorough, sends you to four different labs.  One reports your cholesterol is 200, one says it's 180, one says 150, and one says 130...

After a car accident, you get go to four different body shops for quotes.  One says your car's paint color is taupe; one says it's sea blue; one says its ocean blue; and one calls it sea green...

You whip out four different rulers to measure your foot.  One says it's 12 inches; one says its 6; one says 8; and one says 9...

In all of these scenarios, you would make two conclusions:

1.  These test results (or body shops, or labs, or measuring sticks) are not that scientific!

2.  At least three -- and likely all four -- of these results MUST be wrong.

These parables sum up the world of DNA testing for heritage or "admixture."

We've said it before, and we'll say it again.  But today, Kristen V. Brown, a writer for Gizmodo, published an excellent piece discussing the snake oil that Ancestry.com, 23andme, Gencove, FTDNA, and other labs are selling.

Simply put, these labs cannot tell your ancestry.  I repeat, they cannot tell your heritage, or racial or ethnic admixture.  The science just isn't there yet.  And it might never be.

Brown details how she got four different results from four labs.

She also alludes to, but doesn't state um, confidently enough, about the concept about being confident about your known results.

It's what I jokingly (and longwindedly) call the:

"I was born in a tiny isolated village in the Swiss Alps that has never been invaded.  I know my mom and dad, and there's a video of my birth.  I DNA tested them and they are my parents.  I DNA tested my grandparents too, and they are my grandparents.  There were no affairs and no invasions in my town.  I know my great grandparents too and I am their spitting image.  The church records state I am Swiss going back to 1400.  But HELP, this DNA testing service said I'm British.  Am I British?"  (Or Indian or French or Dutch or whatever) problem.

NO, dummy, you're Swiss...

I for one, always read the fine print.  23andme, for example, states clearly that it cannot spot German (or French) heritage 92% of the time!  Germans make up the LARGEST PLURALITY of Americans.  Americans make up the LARGEST MAJORITY of those getting DNA tests done.  Thus, and I only say this half facetiously: these companies are engaging in the virtual ethnic cleansing of ethnic groups, wiping them off the genetic map, with their statements on people's heritage percentages, that are simply inaccurate.  

And 23andme, is, as far as we can tell, the most accurate lab!

Anyway, kudos to Kristen V. Brown and the people she interviewed for explaining it in her Gizmodo piece.  We suggest reading it.

Are Ethnicity Percentages and Ancestry Calculators from DNA Tests Accurate?

The media has blasted headlines this week that show an incredible ignorance of DNA testing for ethnic percentages.  One, which could have been pulled out of a 1980s tabloid for its ridiculousness, screeched, "Neo-Nazis are taking genetic tests and are deeply upset by the results!"

Neither of the two writers delved too deeply into the subject, and that is because shorthand reporting is easier.  As we've posted, again and again, most of the three major DNA testing sites disclose quite openly that their science is far from perfect.  For example, that if one is German, French, Dutch, Belgian, Austrian, or Swiss, that they cannot discern your ancestry 92% of the time.  (With the US having more people of German ancestry than even English or Irish -- that's a big deal).

In fact, it's quite common for someone taking a test from three different websites to receive three different results!  And as the post beneath this one shows, trying the 40 or so other "ethnicity calculators" available for free on Gedmatch produced...40 different results.

As I often say: if 5 different scales produced 5 (vastly different) weights, you would know that at least four of 'em don't work!  :-)

Anyway, for those looking for perspective, we shouldn't highlight the bad, so we've decided to highlight the good -- or the excellent, rather.

One of the best posts we have seen on the topic comes courtesy of a blog called The Legal Genealogist.  It's called, "Those Percentages If You Must" -- and is a Must Read for people curious about whether ancestry calculations from DNA tests are accurate.

It first, rather hilariously, goes into the various myths and misperceptions about DNA and human history.  Concepts like, "black Irish" or "I have some Native American in me."  Concepts that plague the world of pop-DNA-testing.

After it goes through the science (in easy to understand terms), it reveals what I have posted here time and time again:

DNA testing IS GREAT and REMARKABLY PRECISE for finding you cousins.  It CAN tell you if you are a third-cousin, once-removed (with that kind of precision).  If you don't know your heritage, and that cousin is, for example, 100% Native American -- then it follows that you too have a pair of Native American great-great-great grandparents.

DNA testing IS NOT good at ethnicity percentages and ethnic calculation.  As if anything could be so precise as to tell you that you are "4.2% Jewish."  The science is still just not ready for prime time, and many underrepresented populations, even in Europe, still confound the tests.

(As an aside, ancestry calculators should all produce nice and even results when people get back to the pre-travel era."  In other words, if you had 64 ancestors that were alive in 1500 AD, you should only see multiples of 1.56% chunks, right?  Since no one is half a human!)

The article succinctly concludes with:

DNA testing is a wonderful tool. It can connect us with cousins we’d have never found otherwise to help us reconstruct our family histories.

But in terms of “am I Native American?” “what tribe did I come from in Africa?” “am I 25% Irish?” No. No, no, no.  That’s the absolute weakest aspect of DNA testing. 

Indeed.  Well said.

AND THE WINNER IS... (Comparing Admixture/Heritage Tests on Gedmatch)

Methodology:

• We ran exhaustive tests of several commercial and free DNA-testing labs and ethnicity calculators.  
• To test the sites, we used only individuals with well-documented, double confirmed, 100% known ancestry.  
• We tested multiple males from multiple lines to assure as much as humanly possible no extra-parental events (bastardy) occurred.  
• We even tested minor nobility with documented ties to geographic locales.  
• We used individuals who do not come from cities or places of cosmopolitanism (influx of foreigners).  
• We tested only people with all four grandparents from the same locale.  
• We tested multiple people from different countries in Europe.

As we've posted before, of the commercial labs, 23andme takes first prize, and Ancestry.com is the worst.  23andme provides the most conservative and accurate ethnic ancestry approximations.

We have also completed our testing of all of the ancestry composition tests available on GEDMATCH.  Below is a summary, the results, and the rankings.

• First of all, the specialty labs, Ethiohelix, Gedrosia DNA, puntDNAL, etc. do not even come close to being accurate, at least for individuals of European heritage.
• None of MDLP's tests passed our accuracy gauntlet and correctly called west European DNA.

1. The overall winner, and the clear winner of all the tools currently available on Gedmatch, is the Eurogenes K13 test.  It was pretty darn good at distinguishing DNA from various western European lands, for people of "purebred" ancestry.

2. Coming in second was Eurogenes EUtest K15 v2, which also had a pretty darn good record of accurate calls.

3. An honorable mention, and a close third, with accurate calls roughly as close to the second-place finisher, was Dodecad's K12b test.

• No other tests besides those three were even close to "often accurate."
• No tests, including those three, were much use for accurately calling the ancestry of European "mutts."  We found that the same tests that were accurate with individuals with 100% heritage from one country, were of limited value for serving as an oracle (predicting accurately) the ancestry of individuals of mixed European heritage.

Will Tim Sullivan and Ancestry.com Continue Its VIRTUAL Ethnic Cleansing of Germans?

23andme discloses right off the bat that it cannot identify German or French ancestry 92% of the time.

Ancestry doesn't seem to be able to discern German ancestry too well either, but it doesn't tell its customers that.

Noted: Yet another reader of this blogger just wrote in and shared her experience.  She is 100% German, born in Germany, from a small town, not a big city.  Her ancestors are documented in the region she's from for the last 400 years.  Several of them were well-known and documented.

Ancestry.com called her ancestry as about 50% Scandinavian, 25% Italian, and 25% generic European.  What an epic fail.

How many "white bread" regular Americans, with German ancestry take one of these tests, and misleadingly, their German ancestry is literally wiped away?

We note Germans are America's LARGEST ethnic group, but their ancestry is also often hidden, because German surnames Americanize so well.  For example, Kohl becomes Cole; Schmidt becomes Smith, etc.

As an experiment, with our reader's permission, we ran her raw data through Gedmatch.  Both MDLP (the Magnus Ducatus Lituaniae Project) and Eurogenes were able to call her likeliest ancestry as German.   Dodecad, which specializes in Mediterraneans, was able to call her as German in about half of its tests.

So the question remains:

1.  If the amateurs can call German DNA with reasonable regularity, why the heck can't Ancestry.com?

2.  If Ancestry.com is so bad at identifying America's biggest ethnic group, why doesn't it do the decent thing and tell people?

How DNA Ancestry Testing Works and How Can I Know It's Accurate

When a commercial DNA testing site like Ancestry.com or 23andme or FTDNA tests your DNA, they do not know which snippet came from which of your parents.

For example, if at a given point (a gene, in popular parlance), you have a "C" from your dad and a "T" from you mom (meaning you have brown eyes, but carry the blue-eyes gene), the testing service doesn't know which "letter" came from which parent.

What they then do is try to guess, stringing your DNA out into small chunks or strings of letters.

They then compare these to DNA in their reference database.  23andme's reference database, which is one of the best, if not the best in the world, only has about 11,000 samples in it.  To represent the whole world!


So if you have ancestry from a big country (like France or Germany) or a country that has pockets of deep isolation (like Italy), the odds -- that they have someone from your corner of the country, or your little isolated craggy valley in some mountain chain -- are small.

They then compare the little strings of letters and come up with a likelihood that you have ancestry from one of those reference populations.

23andme has the most scientific test in the business, but it gets French/German/Belgian/Dutch/Swiss/Austrian/Luxembourgisch ancestry wrong 92% of the time.  It most often shows up as "generic Northwest European."  Similarly, 23andme -- the best in the business -- can't identify Italian ancestry 50% of the time.  It often shows up incorrectly as Middle Eastern or Generic Southern European.

The moral of this story is to be patient with the science.  It's not 100% there yet.

If you have documented ancestry from one region, trust your documents.

If you don't have any cousins from a pool you were identified as, then chances are it was a miscall.  (For example, if you have documented Italian ancestry, but it says you are 1/8 Middle Eastern or 1/8 Spanish), then unless you have a known great-grandparent that is 100% such, it's probably a miscall.  (This would mean your parent would test as 1/4, by the way).

Finally, there is a series problem with testing sites, particularly FTDNA's, with the issue of timing.  If you go back far enough, we are ALL Africans, right?  Yet a DNA test telling you that you were African would not be too useful.  Do they mean recently or in the past?

Similarly, as has been well-documented, most European ancestry can be broken down into 3 big chunks: ancient hunter gatherers (Ancient Western Europeans, most similar modern population = Lithuanians); ancient farmers (Ancient Near Easterners, most similar modern populations include Greeks, Sardinians, others); and ancient pastoralists/horse rearers (Ancient Eurasian Steppe Dwellers, most similar modern populations include Ukrainians). But the migrations were really, truly all over the place.

Ancient Near Easterners are NOT modern Near Easterners.  Ancient hunter gatherers in France are NOT the modern French, etc.

If a test tells you that you have some Near Eastern blood, it often is sensing this ancient signal.

It doesn't do you much good for them to say that 6000 years ago, you had some ancestry in the Near East.  Everyone did.

In Praise of Roberta Estes and DNAeXplained.com

In a world of pseudo-science and echo chambers, a few blogs stick out for being mostly in touch with reality.  In the world of Ancient DNA, Dienekes, although less active than before, has pioneered much in the field of DNA, and still has many serious scientists who comment there.

In the world of DNA for Genealogy, one blog sticks out.  It is Roberta Estes' DNAeXplained.com.  Of all the blogs and websites dedicated to disseminating information about DNA, hers is consistently factual, science-based, and yet easy to understand. 

This scientist came across a few of her posts, and I daresay they are mandatory reading for anyone seeking a better understanding of their DNA.  Below are links and highlights:

"Determining Ethnicity Percentages"

Step 1:  Creation of the underlying population data base.
Don’t we wish this was as simple as it sounds.  It isn’t.  In fact, this step is the underpinnings of the accuracy of the ethnicity predictions.  The old GIGO (garbage in, garbage out) concept applies here. . . .

The third way to obtain this type of information is by inference.  Both Ancestry.com and 23andMe do some of this.  Ancestry released its V2 ethnicity updates this week, and as a part of that update, they included a white paper available to DNA participants.  In that paper, Ancestry discusses their process for utilizing contributed pedigree charts and states that, aside from immigrant locations, such as the United States and Canada, a common location for 4 grandparents is sufficient information to include that individuals DNA as “native” to that location.  Ancestry used 3000 samples in their new ethnicity predictions to cover 26 geographic locations.  That’s only 115 samples, on average, per location to represent all of that population.  That’s pretty slim pickins.  Their most highly represented area is Eastern Europe with 432 samples and the least represented is Mali with 16.  The regions they cover are shown below. . .

No matter which calculations you use relative to acceptable Margin of Error and Confidence Level, Ancestry’s sample size is extremely light. . . .
 

"Are You Native American?"

"having Haplogroup Origins and Ancestral Origins indicating Native American ancestry does not necessarily mean you are Native American or have Native American heritage. This is a very pervasive myth that needs to be dispelled. . . .

The good news is that more and more people are DNA testing.  The bad news is that errors in the system are tending to become more problematic, or said another way, GIGO – Garbage in, Garbage Out.

....

There are a very limited number of major haplogroups that include Native American results.  For mitochondrial DNA, they are A, B, C, D, X and possibly M.  I maintain a research list of the subgroups which are Native.  Each of these base haplogroups also have subgroups which are European and/or Asian.  The same holds true for Native American Y haplogroups Q and C.
In the Haplogroup Origins and Ancestral Origins, there are many examples where Non-Native haplogroups are assigned as Native American, such as haplogroup H1a below.  Haplogroup H is European...

One of the problems we have today is that because there are so many people who carry the oral history of grandmother being “Cherokee,” it has become common to “self-assign” oneself as Native.  That’s all fine and good, until one begins to “self-assign” those haplogroups as Native as well – by virtue of that “Native” assignment in the Family Tree DNA data base.  That’s a horse of a different color.