Strange results on DNA Test

3

I hope someone can help me understand my DNA test results from My Heritage.com.

Since i know that my family is kind of mixed, i thought it would be a great idea to see which parts of foreign DNA i inherited. We live in Northern Germany. My maternal grandmother has definitely slavic heritage and my maternal grandfather is supposed to have also a bulgarian or some southern (slavic) background (he is adopted, so thats what we concluded from the information we had.) the maternal side from my father were German Ashkenazi Jews. Only my paternal grandfather was german.

I was really excited for my results. I'm not at Genealogy Expert, but i thought this test help me to find out why my appearance looks like this. I was told many times that I look really russian or ukrainian. My whole face structure is really slavic and I do have really fair skin and hair.

Isn't it possible to estimate what DNA someone might have based on your looks?

I know that Germany is hard to see as one ethnic group, but I definetly wouldn't see myself as Central/Northern-European looking. But thats what i got: A hundred percent(!) result Central-Europe/Northern Europe Ethnicity estimate.

I still don't understand how this could work?

I know that DNA is not evenly passed down. What confuses me is that i read everywhere that nobody could have a hundred percent of one ethnicity and with my family history it just seems... unrealistic.

Svenja

Posted 2017-11-09T08:35:52.523

Reputation: 31

Answers

4

It's important to note that race and ethnicity is not necessarily part of DNA. Ethnicity estimates are based on samples of the current population in different regions and finding patterns in certain DNA markers for those populations which you may share with them, for any reason. It is an estimate based on statistics and not a hard science.

Having that said, it's important to note that DNA estimates give you an idea of where your ancestry came from thousands of years ago, not necessarily hundreds of years ago. You could have ancestors from Ireland, for example, that lived there for 300 years and before that, came from say, Egypt.

My question to you would be, why are you surprised to have 100% DNA from Central or Northern European? All the places you say your family are from are relatively close to each other.

Check out a free tool called GedMatch.com. You are able to upload your DNA to it and check out different "schools of thought" on reading your DNA for an ethnicity estimate. There are a half a dozen or so different scientific groups that have made different conclusions on how to the read the DNA. (My favorite is Happla World.) One group said I was 33% Mediterranean, while another group says I'm 20% Scandinavian. You can decide for yourself what makes the most sense, and none of them are specifically wrong, it's just that the science of ethnicity and DNA inheritance in humans is in it's formative stages still and based on statistics. I hope this helps.

Here's a great article that gives some perspective on what goes on behind the scenes when it comes to using DNS to estimate ethical heritage: https://www.npr.org/sections/13.7/2016/02/12/466379200/can-you-tell-your-ethnic-identity-from-your-dna

Christia

Posted 2017-11-09T08:35:52.523

Reputation: 311

Interesting you should say that Irish may have come from Egypt, as the Pharaohs had the red hair gene! – Charlie – 2017-11-10T07:38:16.820

Red hair comes from Scandinavians and Vikings, not Irish originally, but that's moot. Blond vikings and red-headed Irish are stereotypes. – Christia – 2017-11-10T07:48:48.197

blond Vikings are not stereotypes, 99% of Scandinavian people in the 8th century had blonde hair. If you read Germania by Cornelius Tacitus, you will learn than non-blonde hair was so rare in Scandinavia that those who were not blonde were named thusly (IE redmane, the red, etc). However, red headed Irish is a stereotype as in Germania the Celtic people are variously listed as being red haired, blonde haired and dark haired (a mix). – Charlie – 2017-11-10T14:44:25.100

This isn't really a place for these kinds of extended arguments and discussions. – Christia – 2017-11-10T16:57:47.980

there is no discussion to be had – Charlie – 2017-11-10T19:08:48.090

-1

"I know that DNA is not evenly passed down". Yes it is. You inherit exactly half from both parents (excluding the mitochondrial DNA, which is solely from your mother, and your Y chromosome, which is solely from your father). All 22 other chromosome pairs have exactly 50% from both parents.

However, I don't know how good your genetics knowledge is, but genes are not EXPRESSED 50/50. For example, if we simplify to say nose shape. One may say " you have your father's nose" as your father's gene is more dominant than your mother's.

Onto the next question, why is all your DNA 100% Northern European? It could be down to a few things, but the most likely possibility is that the test results aren't very accurate. DNA testing is still in its infancy and has not been refined to the point where it can recognise the difference between a Slav and a German. As more people are added to the database and geneticists learn more, the results will become more accurate. At the moment, scientists sometimes struggle to identify between species, such as Neanderthal and Denisovans or even Neanderthal and Homo Sapiens!

Charlie

Posted 2017-11-09T08:35:52.523

Reputation: 1 523

It isn't exactly evenly passed down. Since you can only inherit 50% of each parents DNA, and that 50% is random, you have no way of knowing which ethnic DNA you're going to get. For example, I am Irish, but didn't inherit any of it from my mother. – Christia – 2017-11-10T05:14:24.793

What do your mean "That 50% is random"? – Charlie – 2017-11-10T07:36:44.330

Yes, you and siblings will all inherit a random set of the 50%. – Christia – 2017-11-10T07:37:49.267

1So what you're saying is the value of bases inherited is 50%, but which 50% is not predictable? That's not really true. Off your mother is truly ethnically Irish, then that would show in your DNA. If a gene is not dominant, it is still passes on as a carrier gene. – Charlie – 2017-11-10T07:42:12.640

That is what I am saying and it is true. You could literally inherit all or none or some of that Irish if she also has other ethnicity. It's not a high probability, but one sibling could show up mostly Irish while another mostly Italian. Ethnicity genetics is not the same as hair color and eye color. It's an estimation based on statistics of a wide variety of genetic markers. Otherwise all siblings would be identical. https://blogs.ancestry.com/ancestry/2014/03/05/understanding-patterns-of-inheirtance-where-did-my-dna-come-from-and-why-it-matters/

– Christia – 2017-11-10T07:44:53.200

Either your edited your answer or I mis-read some things. – Christia – 2017-11-10T07:57:33.393

@Christia The chances of a massive change in ethnicity result between siblings cannot be held to the massive difference in DNA, it is the fault of the biologists analysing the DNA. Yes, the genes expressed will be different but not that different. Not to mention the ethnicity markers (parts of the genome used by geneticists to predict ethnicity) will show the carrier genes too, not just the ones that are expressed. – Charlie – 2017-11-10T15:46:27.893

While exactly half of our autosomal DNA is from each of our two parents, it is not true that 25% of our DNA comes from each of our four grandparents. There is substantial mixing that occurs when ova and sperm are made, and the result is random. The contribution of one grandparent can be as much as twice that of another grandparent in a particular case. Over many individuals,, the average amount will be 25% from each grandparent, but it will not be exactly that for each of the individuals. – RobertShaw – 2017-11-14T19:54:02.407

@RobertShaw you are right that not each grandparent's contribution is 25%, but this is not because of changes to sperm or eggs, it is because of recessive alleles being dropped for dominant alleles. If you have a grandparent that is Aryan, for example, and three black grandparents (and let's assume they are fully black and hence are not carriers of any light pigmentation) then since your Aryan grandparent has only recessive alleles they will completely dissappear (they won't even be recessive alleles) after two generations and hence the DNA you share is much less than 25%for that grandparent. – Charlie – 2017-11-14T21:13:31.167

1

@Charlie - recessive and dominant genes don't really have much to do with the percentage of DNA that comes from a grandparent. The percentage of DNA from each grandparent depends on how the genes cross over during meiosis. The cross over points are not right in the middle - they happen anywhere along the chromosome. Take a look at the picture in this link for an illustration: http://www.phschool.com/science/biology_place/labbench/lab3/crossovr.html

– Brainstorm – 2017-11-15T03:25:06.487

1Also, there can be multiple cross-over points for any given chromosome. The number of cross-over points is random, with the distribution of the number of cross-over points being dependent on sex and associated centimorgans. On average you will get 25% from each grandparent. But some people are not average. – Brainstorm – 2017-11-15T19:31:26.623