Let me say that again, ethnicity results are NOT an accurate predictor of heritage, or parentage. This is a great deal of confusion swirling around this topic. The fact that people are doubting parentage, or grandparentage, based on ethnicity results alone is alarming.
This week I receive this inquiry:
- I recently found my suspected birth father but he says he’s probably not because he has 2 generations of Amerindian in him and my tests came back negative until I did the analysis at GedMatch and found it to show Amerindian in small traces.
- I recently took an ethnicity test and it showed less Scandinavian than it should. My father’s grandfather was from Sweden. Since my Scandinavian is less than 25%, is my father really my father, and is his father really his father? Now I’m really confused and frightened.
Last week, I receive this inquiry:
- My father and I both tested, but my ethnicity doesn’t all seem to be shared with him. Now I’m doubting whether he is really my father.
- I received my ethnicity results, which showed no Native ancestry – but I know my ancestor was Native because she looks Indian in her photo.
And these are, by far, not the only inquiries in this vein. Some variation arrives almost every single day.
Be still my heart. Let me say this again
First, let’s talk about why, and then I’d like to share what I consider to be a perfect example with you.
Why is ethnicity alone not an accurate predictor of parentage or heritage?
- The field of population genetics, which is the underlying science beneath ethnicity predictions, is in it’s infancy. This means that if you were to test with the various vendors who offer these tests, your results would come back with different readings, sometimes significantly different readings. And this is just for one person – you – not the combination of two people. You can see my results from various vendors in the article, Which Ethnicity Test is Best?
- Ethnicity results from all vendors can only be considered estimates based on the people they are comparing your results to (reference panels) and their internal software algorithms.
- Some vendors have more experience than others.
- I have seen ethnicity results that reflect an ethnicity for a child that is not included in either parents’ ethnicity results, when the parents are unquestionably the biological parents of the child. Clearly, this can’t be accurate. I suggest reading the article, Ethnicity Testing, a Conundrum, to understand more about how ethnicity estimates are generated.
- You can easily have an ethnicity not found in one parent, if you inherited that portion of your DNA from the other parent.
- You may not have inherited a portion of DNA from a parent in which a particular ethnicity is found. Your parent may have it, and you may not have inherited that piece of DNA. For examples of how and why this works, please read the article, Ancestral DNA Percentages – How Much of Them is in You?
- Ethnicity estimates are only considered to be predominantly accurate at the continent level, specifically, Asia, Europe, Africa, Native American and Jewish. Yes, I know that Native American and Jewish are not continents, but their DNA is different enough from the rest that the presence of Jewish or Native DNA is presumed to be, generally, accurate, unless they are very small amounts which could also be noise.
- Unless you’ve tracked your ancestors back several generations through genealogy, you won’t have an accurate expectation of the percentages of ethnicity. For an article describing how to do this, please read, Concepts – Calculating Ethnicity Percentages and Concepts – Percentage of Ancestors’ DNA.
- You do inherit exactly 50% of the DNA of your parents, but you do NOT necessarily inherit 50% of each ancestors’ DNA that your parents carried. For example, if your parent carries 6.25% of a particular ancestor’s DNA, which is equivalent to that of a great-grandparent, you may or may not inherit half, or 3.12%, of that ancestor’s DNA. You will inherit someplace between none and 6.25%. Please read the article, Generational Inheritance, for more information about how DNA is inherited in successive generations.
- You may not inherit a portion of a specific ancestor’s DNA that reflects a particular ethnic admixture, or at least not that the reference panels used by various companies can identify as associated with that ethnicity today. For more on how companies determine ethnicity, please read Determining Ethnicity Percentages.
- In the case of minority admixture, meaning when you carry a small amount of admixture from one ethnicity – it may or may not be noise. If it’s genuine, it may or may not be found by ethnicity tests.
- The absence of an ethnicity in your ethnicity results is not evidence that the specific ethnicity was not present in your ancestor, especially back in time several generations.
- The lack of an ethnicity in your results does NOT equate to the fact that an ancestor of that ethnicity is not your ancestor. In other words, you can have a Native American ancestor, back several generations, and not show Native American ancestry in your ethnicity results. Absence of evidence is not always evidence of absence.
- In the case of admixture involving both Native and African, and especially in the US, your Native or African ancestor(s) may have been admixed themselves, so you don’t really know what to expect in terms of percentages.
- How you look, known as your phenotype, may or may not reflect perceived or real heritage at the level you expect.
Can Ethnicity EVER Predict Parentage?
Ok, given the above, is there an example of where an ethnicity test MIGHT cause us to wonder at parentage?
At one time, I would have said yes, if you “look white” but your presumed parent was considered to be black, or vice versa. I’m using black and white here as examples because in the US, we have a lot of admixture and “white” and “black” are different enough from each other that one would expect to be able to visually tell the difference, especially in relatively recent generations.
However, that’s not always true. Remember the story about the black twin and white twin from the same parents? Here’s the Snopes confirmation, along with photos.
My Friend, Rosario
Rosario has been most gracious in allowing me to share his story in advance of a book he is currently penning. His journey is particularly poignant, considering the discussion above.
Rosario studied at Harvard and then became…are you ready…an opera singer. Rosario was raised as an Italian man, specifically Sicilian. Fitting, as in Luciano Pavarotti. Those good Italian operatic genes.
Except…Rosario discovered that he isn’t Italian.
What he is, however, is a genealogist.
Rosario’s mother was taken from her parents and raised in foster care. She had a brother who was shipped off elsewhere, to other states, bouncing from one terrible situation to another until his untimely death. Separated as a child, she had little contact with her brother until they were adults, and then only on two occasions. Her brother and her parents were hushed-up secrets.
Rosario’s mother told him that her heritage was Sicilian, and Rosario became, culturally, a Sicilian man.
Interested in the challenge of his mother’s past, and as genealogists are inclined to do, Rosario started digging in like a dog after a bone. He wanted to share his proud Sicilian heritage with his children.
What he found would amaze him, shock him and leave him reeling – all at the same time.
The Truth Surfaces
First, Rosario found inconsistencies.
For example, he found three different birth certificates for his mother. No one has three birth certificates, but his mother did. One without a father’s race, one with the father’s race redacted and then a third one with all information present. The father was identified as “black” but given that Rosario was raised as Sicilian, an area in Europe where people are darker and could be identified as black, that was Rosario’s assumption. Made sense and might also explain the confusion and the three different birth certificate versions.
Rosario’s first real clue came when his DNA results were returned showing the following ethnicity mixture:
- 18% Sub Saharan African
- 2% Malagasy
- 2% Native American
- 78% European
Rosario didn’t exactly know what to do with these startling results. They couldn’t be true, because his father was white, his father’s parents were white and his mother’s parents were Sicilian.
Years would pass before additional inroads would be made, hindered by the legal system, his mother’s failing health, young children of his own and the lack of relatives. Rosario had no one to ask.
Eventually, Rosario would discover that his grandparents, his mother’s parents, one white and one black, were prosecuted for engaging in sexual activity with each other – in Vermont.
In fact, they were not allowed to marry due to their different races, and their children, Rosario’s mother and her brother, were removed from their parents when the parents were sent to prison for the crime of having sex with someone not of their race.
Rosario’s grandfather was black. And yes, he was sent to prison, for having sex with a white woman – in the northeast – not in the deep south. Rosario’s white grandmother was sent to prison as well, which is when Rosario’s mother was placed in a foster home and her “darker brother” was sent away – far away – to another state where he was caught up in a horrific maze of institutional abuse.
The photo above is from one of only two times as an adult that Rosario’s mother saw her brother.
Given what had already happened to Rosario’s mother, yanked from her parents and brother and placed in a foster home by the age of 9, it’s easy to see why she fabricated the story of her family being Sicilian. Dark-skinned Sicilian was much safer than “half black” in a place and time when people were sent to prison and children ripped from their families. Her brother would eventually commit suicide as the result of the abuses he suffered as a child – and not at the hands of his parents but as a result of horrible system in which he was systematically and repeatedly abused by adults who were supposedly “better” than his law-breaking parents.
For those of you who have never suffered the horrors of a family story in which your parent or grandparents were abused or mistreated, either by people they trusted or a system that was put in place to help them – good for you. But trust me, these revelations change the entire picture of who you think you are, your self-identity – and they will, guaranteed, rock your world to the point of physical nausea and literal nightmares.
After adjusting for a bit, trying to absorb his new reality and attempting to come to grips with the abuses suffered by his grandfather, grandmother, mother and uncle, Rosario was beset by a new drive to get to know his until-then-missing grandparents.
Who were these people, as people? What were their lives like, before and after prison? Did they love each other? What did they look like? Were there any pictures?
Rosario looked high and low, and then finally, finally…through a hint planted in his mind in the middle of the night – Rosario woke up knowing the answer.
Earlier this year, Rosario was able to obtain his grandfather, Jerome Barber’s picture – a mugshot, the only photo he, or his mother, has ever seen of this man.
Jerome Barber’s Heritage
If Jerome Barber was entirely “black,” then his child, Rosario’s mother, would have been half black, or 50%, and Rosario would be 25% IF Rosario received exactly 25% of this grandfather’s DNA.
Looking at an expected DNA contribution of 25% African, given a black grandfather, compared to Rosario’s reported rate of 18% sub-Saharan African shows that expectation and reality can vary widely. In this case, there is a 7% difference with only one generation between Rosario and his “black” ancestor. It’s probable that Rosario’s 2% Malagasy and 2% Native also descend from this line based on testing of other family members including his mother and newly discovered relatives on his father’s side.
However, even with Rosario’s 18% sub-Saharan African and a black grandfather, until I told you, one would never look at Rosario and expect him to carry African heritage.
In photos of Rosario’s mother, you’d never guess that she is half black and half white, which is why she was “kept” and placed with a white foster family, while her brother, who was darker, was sent elsewhere. Unfortunately, Rosario’s uncle passed away before DNA testing was available.
So, in this case, Rosario’s phenotype, meaning how he looks, as compared to his genotype, his DNA contents, is deceiving and so is his mother’s.
Rosarios’s mother has DNA tested, and her results show only 28% sub-Saharan African where 50% would have been expected with a 100% black father.
Rosario’s expected amount of sub-Saharan African DNA would be 14% or half of his mother’s 28%, if you are calculating from his mother, but if you are calculating from a fully African grandfather, Rosario’s amount of African DNA would be expected to be 25%. Clearly, Jerome Barber wasn’t entirely black.
Expected percentages of DNA if Rosario’s grandfather was 100% African are shown below for each generation.
As you can see in the above calculations, based only on Rosario’s grandfather being entirely African, there is a significant difference, especially in his mother’s generation.
Looking at these DNA amounts differently, the next chart shows the expected amount of DNA calculated on the percentage of DNA the parent actually carries. Again, we begin with Rosario’s grandfather at 100%.
Working backwards, given the amount of African DNA that Rosario’s mother has, 28%, Rosario’s grandfather may have only been about 56% African himself.
An awful irony.
Now that you know, you can look at Rosario and his grandfather’s photo together, and you can see the resemblance.
This same scenario works in reverse too. I cannot, tell you how many times people have sent me photographs with the idea that their ancestor “looks Native” but the DNA shows none or a small amount of Native admixture. In those cases, the DNA may show less than expected or no Native admixture because the DNA has washed out in the subsequent generations, the testing panels aren’t picking it up, or the ancestor wasn’t Native to begin with. It’s extremely easy to see a resemblance, especially if it’s something you are looking “for” or expect to see.
If ethnicity isn’t a good predictor and is highly variable, then how does one identify a parent?
As I mentioned previously, every child inherits half of each parent’s DNA. Therefore, if any child and parent both take an autosomal DNA test from a vendor that provides matching and centimorgan (cM) amounts, in addition to ethnicity, you will know for sure if those two people are parent and child.
In the graphic below, I’m showing my mother’s DNA test which shows me as a match at Family Tree DNA.
You can see that the relationship is identified as parent/child, which means, genetically, the software can’t tell which one of us is the parent and which one of us is the child, but only a parent and child will share this amount of DNA.
By the way, the only reason I have my mother’s autosomal results to utilize, above, is because Family Tree DNA archives the DNA of their customers for 25 years, which allowed me to run the autosomal Family Finder test on her DNA years after her death.
You can also see in the chromosome browser, above, that I match my mother on the full length of every chromosome. The gray areas are not measured by the testing companies. Anyone who is not part of a parent/child relationship will not share all of all 22 chromosomes with someone who is not their parent or their child, except for identical twins. Said another way, if you are a parent or child, the entire portion of every chromosome 1-22 will match and be fully colored, as above.
Identical twins will match the full length of every chromosome too, but instead of the child matching 50% of the parent’s DNA, identical twins match exactly – 100% – not 50% – so the software vendors can tell the difference.
You can view the expected amount of DNA sharing for various relationships on this chart from the article, Concepts – Relationship Predictions.
Therefore, if you want to know whether or not someone is a parent, both parties must take an autosomal test at a vendor who provides matching between participants along with the amount of matching DNA and relationship predictions. Ironically, the test that provides the matching is the exact same test that provides ethnicity results – so if you tested at one of these vendors, you don’t have to take another test. You just have to look at matching results, assuming both people tested. Even if both parties aren’t available to test, such as the parent, if you can test a close relative of the purported parent, such as a sibling and still obtain probable confirmation, because close relatives tend to match within prescribed ranges.
Please, don’t just look at ethnicity results and begin questioning, or presuming.
The vendors who provide autosomal tests along with chromosome browsers are Family Tree DNA, used in the examples above, and 23andMe.
Ancestry also reports parent/child relationships and total matching DNA in centiMorgans (cMs), minus some amount of DNA removed by their Timber process, but does not provide a chromosome browser. MyHeritage reports relationships and cM amounts, but their cM matching amounts are problematic today and they do not provide a chromosome browser. Still, one should be able to discern a parent/child relationship from either Ancestry or MyHeritage.
You can read about the various vendor offerings in the article, Which DNA Test is Best?
Genetic Genealogy Tests are Not Legally Binding
Lastly, none of the genetic genealogy tests are legally binding relative to paternity, even though they can and do clearly inform of parentage.
These tests aren’t binding because the testers’ DNA samples lack “chain of custody,” meaning the DNA sample was not given in an environment where the identities of both testers can be legally proven. It would be very easy to return a negative paternity result by having your neighbor or buddy swab or spit for you. In other words, if you are looking for legal proof, to be used in legal proceedings, you need to consult with an attorney, follow their advice and utilize the methodologies, laboratories and procedures in your state or country to achieve your legal goals.
However, if what you are looking for is simply an answer, do NOT, NOT, NOT rely on any ethnicity results or appearances as hints. Instead look at chromosome matching between the potential child and parent or close relative in the absence of a parent.
Rosario’s comments relative to ethnicity results and testing are very profound, especially given his recent experiences:
In your published articles, you astutely state the extremely variable nature of the companies’ platforms and methodologies. This begs the question, “is admixture variable or are the companies’ platforms?”
I think that this is the more appropriate question to ask.
People are taking their admixture results literally and that is a dangerous game to play. Families break up over this potent issue. We should tread lightly until we can demonstrate a more scientific conclusion than what is currently being offered.
I agree with Rosario, and would hazard an answer to his question as well.
How much DNA we inherit from any ancestor other than our parents is variable. Which DNA we inherit from any ancestor is variable.
The vendors test results, the reference populations and their internal algorithms are all variable.
Therefore, everything about ethnicity testing is at least somewhat variable – and is exactly why ethnicity testing should NEVER be interpreted as an indicator of parentage.
Chromosome matching is not variable relative to a biological parent/child relationship. Children always inherit half of the autosomal DNA of each parent on chromosomes 1-22.
Correction note: Jerome’s surname corrected to read Barber. Jackson was Jerome’s mother’s surname.
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