Questions tagged [dna]

For questions about using DNA to further knowledge of family history, relationships, ethnic origin, and overall ancestry. Most common tests include Y-DNA, mitochondrial DNA, and autosomal DNA.

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17
votes
1answer
662 views

How can DNA testing aid me in my genealogy research?

My basic understanding of DNA testing is that it can tell you where your ancestors came from. How can just knowing the ethnic breakdown of my ancestors help me? What if I already know where my ...
15
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1answer
4k views

Proving Native American ancestry using DNA testing?

I saw on The Generation Project where a man took a DNA test that showed he was some percentage Native American or was the chance that he as Native American. Can a DNA test prove that I have Native ...
11
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5answers
4k views

Why are 99% of my Ashkenazi DNA matches not in the Middle East or Central Asia?

I took DNA tests through four major services: familytreedna, 23andMe, ancestry, and NatGeo/Helix. I am identified no less than 85% Ashkenazi. I also ran my results through dnaland, gedmatch, and ...
11
votes
2answers
777 views

Asking distant cousins for DNA?

In my family we have a DNA contradiction – two cousins (at about the 4th cousin level) took a Y-DNA test, but did not match and had two completely different haplogroups. Since then, I have traced ...
11
votes
3answers
2k views

Generational Loss of Data with DNA Testing

I have personally done the Y-DNA, the add-on Y-block with FamilyTreeDNA, mtDNA, and new FamilyFinder/AncestryDNA (via Ancestry) which i plan in transferring to FamilyTreeDNA just recently as a base ...
11
votes
4answers
327 views

What DNA data is important to record?

When DNA testing is done for genealogical purposes, they send back reports with all sorts of incomprehensible information. I want to save the important information with the person in my genealogy ...
10
votes
4answers
425 views

How to narrow down the best DNA donors in a large family?

I've been doing genealogy for quite a while, but am new to DNA, having purchased six tests for Christmas. Not all results are in yet, but I have a few good matches. I'd like to get four more kits in ...
10
votes
6answers
43k views

Is a half-sibling match on AncestryDNA reliable, or is more testing needed?

I'm new at the DNA testing but here are my results. After receiving my DNA results in January 2016 my first match was with a known cousin who is also on Ancestry with a score of 959 centimorgans at 41 ...
10
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5answers
11k views

How to get an elderly person to provide saliva sample for DNA?

I have an Ancestry autosomal DNA kit that we are trying to get a 95 year old woman to take and having trouble. I provided the hints that 23andme offers to my cousin that is trying to administer the ...
10
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3answers
37k views

What is the significance of “shared centiMorgans”?

I've had my autosomal DNA tested and the site I've used (FamilyTreeDNA) tells me that I have a "Shared centiMorgan length" of 48.08 with my closest match and the "longest block" is 28.89. FamilyTree ...
9
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4answers
488 views

Establishing link between 7th cousins using DNA?

In linking two branches of my family a male sibling relationship in 1705 is somewhat questionable. Following male lines back to that period, through seven generations, can DNA analysis be reliably ...
9
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1answer
619 views

My Father passed away - next test(s) on what remains of his DNA sample?

I posted this general question over at the forum on FamilyTreeDNA. Though I received a reply, there is still no answer to my question, so I thought I'd try my luck at posting here. Anyhow, in early ...
9
votes
1answer
1k views

How does the GEDMatch Relationship Tree Projection Tool Work?

This is an advanced question. I know how to use the tool. A good answer will explain how it does what it does. An ideal answer would come from the person who wrote the tool for GEDmatch. The purpose ...
9
votes
1answer
561 views

Can DNA test prove an African ancestry?

Are DNA tests reliable enough to verify ancestry from Africa? How many generations would appear in such results, since if we go back enough we'll find that human race generated in the African ...
9
votes
1answer
100 views

Is Whole Genome Testing in any way useful for Genealogy?

There are several DNA testing companies out there that are excellent for genealogists. These include Ancestry DNA, Family Tree DNA, MyHeritage DNA and 23andMe. These companies provide match lists of ...
8
votes
3answers
522 views

Does having child of DNA tested parent help find parent's DNA ancestors?

If a parent (Charlie, a male) has been autosomal tested, and does not have either of his deceased parents (Alice and Bob) tested, and thus he does not have his autosomal DNA phased between their ...
8
votes
3answers
315 views

“Resolution” of DNA testing

What is the spatial/cultural "resolution" of DNA testing for genealogical purposes? How finely can it be used to estimate where a particular person's ancestors were from? I am interested in testing ...
8
votes
3answers
2k views

Interpreting X DNA?

I guess I need a "dumbed down" explanation of these things, since I don't understand the explanations I've read. First, I have a 3rd cousin match from Ancestry who uploaded his info for me on ...
8
votes
3answers
236 views

Using shared cM to determine likelihood of misattributed paternity?

My ancestor Harriet Smith was born in the mid-1850s in England. Her birth certificate shows both of her parents (John Smith and Sarah Johnson). For the purposes of the birth registration, John and ...
8
votes
4answers
7k views

Why would I export my raw DNA data?

23andMe, AncestryDNA, and Family Tree DNA all allow you to export your raw DNA results. What is the advantage of doing this? Is there anywhere I can import it for additional analysis?
8
votes
2answers
3k views

Understanding chromosomes and centiMorgans

I am very new to this so please be patient with me. I had a DNA test via Ancestry which didn't tell me very much and so I uploaded the data to GEDmatch. My top 3 matches are: A:11 chr matches, ...
8
votes
2answers
13k views

Genetic Distance to Generations Calculation for Y-STR DNA tests

As a follow-up to the Q&A on Generational Loss of Data with DNA Testing, which described generational detail loss really well for Autosomal, I am now looking for a calculation or some basic ...
8
votes
1answer
237 views

What's the best way two people that share a surname can determine they're not closely related?

My girlfriend and I both share the same last name and our families claim they are both from the same Korean surname "clan". This is a huge sticking point for her father. I know so far with certainty ...
8
votes
1answer
1k views

Working with autosomal DNA results

I have the automsomal DNA results for myself, 3 full sisters and 1 half-sister. We all share a mother, and we all tested with familytreeDNA. Our results are uploaded to gedmatch.com. Our parents are ...
8
votes
2answers
312 views

What factors should I consider when choosing a DNA-testing service?

I and my half-sister are considering having DNA testing done, for the following primary reasons: To attempt to identify my sister's paternal line. We have no information about her father, who may be ...
8
votes
1answer
373 views

Interpreting DNA matches from endogamous communities?

Mystery match, does not know father. Matches me on mother's paternal side. Me and match: 376.3 cM,15 matching segments, largest segment 47.2cM Me and his daughter: 84.7cM, 4 matching segments, ...
8
votes
1answer
6k views

Which Gedmatch admixture calculators are most useful for an individual of predominately African American descent?

According to my Ancestry DNA autosomal test results, my admixture is 70% Sub-Saharan African, 25% European and 4% Native American. Which Gedmatch admixture calculators might I find particularly useful ...
7
votes
6answers
37k views

Finding haplogroup through raw DNA data?

I just got my results from AncestryDNA. What are some ways to find my haplogroup through my raw DNA data?
7
votes
2answers
4k views

Is it common to have no close yDNA matches on Family Tree DNA?

On Family Tree DNA, I have a yDNA-111 test showing only one match at the yDNA-67 level for another test that happens to be 111 also and that has a genetic distance of 7 marker changes and a 50% TIPS ...
7
votes
3answers
22k views

How to interpret a reasonable X DNA Match, but no shared cM Autosomal result on GEDMatch?

I recently uploaded one of the Autosomal DNA results I manage to GEDMatch.com and ran the X-Match routine and came up with a puzzling result. The strongest result by far on the test has 37.2 shared ...
7
votes
3answers
186 views

DNA results from Ancestry

A friend of mine took a DNA test with Ancestry.com a while back. Now I (a trained mathematician) am being asked to help interpret the results, and I am finding myself totally out of my depth. The ...
7
votes
1answer
297 views

Explaining major discrepancy in genomic position between Gedmatch and MyHeritage?

I have identified a discrepancy with several test kits that were tested at Ancestry, with results transferred to both Gedmatch and MyHeritage, all relating to the same area at the end of chromosome 19....
7
votes
2answers
154 views

Making Research Plans for studying the Genetic Genealogy of an Adoptee?

I have accounts on 23andme, gedmatch, ftdna, and ancestry.com's ancestrydna (all autosomal at this point). I also, even though I'm adopted (from bulgaria, have the full name, most recent address (as ...
7
votes
1answer
4k views

What DNA test does 23andMe perform?

What DNA test does 23andMe perform? I can't find it stated anywhere on the website. The FamilySearch Wiki appears to imply that they perform the autosomal test and use that to infer Y-DNA and mtDNA ...
7
votes
3answers
4k views

How do I find out which group/population/part of East Asia my ancestors are from?

AncestryDNA says I am 100% East Asian. Can I use my raw DNA data to find out which specific part of East Asia my ancestors come from?
7
votes
3answers
133 views

Is there anything wrong with using small DNA segment matches as evidence?

Many people find relationships with other people that they only share a small amount of DNA with, e.g., 10 cM or less. They then, after researching the other person's tree, find a common ancestor and ...
7
votes
1answer
274 views

Mitosearch Data Entry

I'm entering my uncle's mtDNA results from FamilyTreeDNA into mitosearch. But I ran into two problems that their help doesn't seem to answer. Problem 1: FamilyTreeDNA provides differences from two ...
7
votes
2answers
439 views

Partial matches on Triangulated DNA segments

With DNA information from FamilyTreeDNA, I have determined trangulation groups. I have chromosome segments of significant size (> 10 cM) over which A (myself) matches B (my known cousin) and A (myself)...
7
votes
3answers
3k views

Converting AncestryDNA 1.0 file format to 2.0 and vice-versa?

I noticed today (1 Jun 2016) that AncestryDNA.com has converted over to their new 2.0 file format, where as about a week ago they were still on the 1.0 format. Both file formats state they are ...
7
votes
1answer
1k views

Why would Y-DNA matches have different paternal haplogroups?

I am researching Clements ancestry and am puzzled that kits that are matches on almost all 111 Y-STR tested markers would be categorized into different paternal haplogroups. Specifically consider ...
7
votes
1answer
440 views

Template or Tool for Comparing Y-DNA Results

I am looking for a tool, preferably an excel template, I can run on my computer that I can use for comparing Y-DNA results across multiple types of Y-DNA tests. I realize some version of this exists ...
6
votes
3answers
5k views

Any issues getting FTDNA sample vials through airport customs?

I'll be flying internationally next week with the express purpose of collecting DNA samples from some Aunts and an Uncle. I'm bringing a number of FTDNA kits with me (totalling 8 vials). I plan on ...
6
votes
3answers
4k views

Determining if an autosomal and X-DNA match is my half-sibling?

I am adopted and have info on my maternal side, but not paternal. I recently got a match through AncestryDNA with someone saying we were close relatives. This man and I share 2086 centiMorgans in ...
6
votes
6answers
10k views

Can Ancestry.com DNA matches be wrong

I (female) had an unexpected half sister match (1,866 cM across 49 segments) in Ancestry.com. We are about the same age so I'm assuming sibling. Upon closer examination I realized my brother(A) was ...
6
votes
1answer
189 views

Reconstructing autosomal genomes of Mayflower passengers

I imagine no group of 100 people has been as genealogically documented as the Mayflower passengers. And with an estimated 35,000,000 descendants living today, the number of descendants genetic tests ...
6
votes
1answer
8k views

How far back is a mtDNA match of genetic distance 2 likely to be?

On FamilyTreeDNA, for haplogroup H1, my closest matches are all genetic distance of 2 for HVR1, HVR2, CODING REGIONS. I don't see any tool to predict the number of generations like we have for yDNA ...
6
votes
2answers
1k views

Is this adopted DNA match my niece or half sibling?

The adoptee and I have an autosomal total segment of 2138.8 cM the largest segment is 122.6 cM. The X-DNA is 115 total with the largest segment at 95. My son matched the adoptee with autosomal 1124.1 ...
6
votes
4answers
1k views

Acceptable number of no-calls in autosomal DNA test results?

Using Gedmatch's file diagnostics, an autosomal DNA test kit I manage shows that there are 31200 (4.4%) no-calls. In most matching algorithms, a no-call is treated equivalently to a match. Therefore, ...
6
votes
1answer
267 views

Is longest cM a better predictor of relatedness than total cM for Ashkenazi Jews?

As an Ashkenazi Jew, I'm used to matches being predicted to be closer than they really are. My father recently got a match to an adoptee of 348.3 shared cM, with a longest segment of 57.4 cM (...
6
votes
4answers
312 views

Is birthmother sharing only 1549 centimorgans possible?

I'm adopted. I found my birthmother over 20 years ago. After a DNA test it shows we share 1549 centimorgans over 51 DNA segments. Is it possible that the DNA test had inaccurate results while ...

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