12

(Note: I did not view the updated part of the question before writing this answer, so my original answer does not address the specific scenario added in the update. See the section below the dividing line for the specific question of the generational 'range' of various tests.) The Problem with Ancestry DNA You're probably already aware of this, but Ancestry ...


10

The first thing to understand is that this is a defined unit (actually a centiMorgan, one hundredth of the original invented unit named for the geneticist T H Morgan) not something that is based on a physical standard. Although it is talked about as though it were a measured length,the cM (also called a mapping unit) is actually a statistical notion. The ...


10

There is a service to turn a physical chromosome position (measured in base pairs, "bp") into a linkage position (measured in centiMorgans, "cM") here: http://compgen.rutgers.edu/map_interpolator.shtml To get the cM for a segment given its begin and end positions, you would use the web site to convert each of the two positions into linkage positions and ...


10

The amount of autosomal DNA shared by 6th or 7th cousins is quite small. Some will share no detectable DNA. The latest data of the Shared cM Project shows that seventh cousins share between 0 and 57 cM, with an average of 13 cM. The Y-DNA plays no role in this. Your female match has two X-chromosomes, and you have an X and a Y, but assuming this cousin is ...


10

It looks like this may be due to a difference in the Genome Builds (https://en.wikipedia.org/wiki/Reference_genome#Human_reference_genome) used between the two tools. GEDMatch reports that they store data in Build 36 format (https://www.gedmatch.com/gedwiki/index.php?title=DNA_Upload). Louis Kessler noted that MyHeritage raw data is downloaded in Build 37 ...


9

I obtained my Y-DNA haplogroup from my AncestryDNA raw DNA file using the first method detailed in this link: https://www.geneticgenealogist.net/2016/01/how-to-get-ydna-haplogroup-from.html In short, it goes through 3 steps: 1/ you convert your AncestryDNA raw DNA file into 23andme format using a small VBS program you can obtain from here: drive.google....


9

I think the prior answers are either misleading or wrong, and people should not miss out on the opportunity to get great DNA information because they were discouraged by those answers. If you have the DNA for Charlie (the parent), and any of Charlie's children (Dick, Elizabeth, Frank, and George), you can at least partially phase a child (and thus pseudo-...


9

I think you just posted that question to make all other genealogists envious of what you have to work with. :-) But seriously, yes, there are some things you should do and do as soon as possible (i.e. before the candidates are no longer here). Seeing your goals, I would suggest you work towards trying to get sets of three siblings tested at your parents ...


8

23andMe detects SNPs (single nucleotide polymorphisms) on the nuclear chromosomes and the mitochondrial chromosome. SNPs are places where one "letter" (base) of the DNA sequence is known to have two variations (or, in very rare locations, three or four variations) occur in the human population. They use a special chip that simutaneously checks for the ...


8

Each entities lab's time are different and it also depends on what test you perform. This is due to them queuing up tests into large scale batches to use shared labs since many do not have their own lab with the exception of FamilyTreeDNA. The general process for the tests appears to be the following which is important to understand when examining ...


8

The adoptee is very likely your niece, specifically the half-sibling of the niece you have also tested. The relationship could be diagrammed as follows: The X-DNA is key to determining this relationship. A useful article to help understand X-DNA matches is X Chromosome Recombination's Impact on DNA Genealogy. You know that the adoptee is a nearly 100% half ...


8

I had my 93 year old uncle take a test after he agreed to do it. I did not feel comfortable asking him to do it, or for me to attempt to administer it. My uncle was at a nursing home. I asked one of the health care aids to administer it. My uncle trusted the aid and even though he was uncomfortable for a few seconds, the aid knew how to handle it and it ...


7

One of my favorite math teachers in high school told us that whenever we got stumped, we should draw a picture to get a better definition of what the problem was. Here's a recent (12 June 2015) article by Louise Coakley, X-DNA's helpful inheritance patterns. Coakley published several graphs with the possible lines of descent marked out. Coakley says: ...


7

For a person who is related somewhat distantly (say, third cousin or farther), it is common to share only a single DNA segment (if any). The shared segment may be located on an autosome or, if the relationship is through relevant maternal connections, it may be located on the X chromosome. Thus it is quite common to have results where there is a shared X ...


7

The short answer is being you have completed a very basic Y test and you should have met ftDNA's internal requirements of first doing a Y-## test before being able to order a BigY test and even if your kit does not show it, call them and they will add it to your cart or send you a special checkout URL.If they insist on adding a Y test you can request they ...


7

The result should be reliable in that it shows a close relationship. As shown on the Autosomal DNA statistics page on the ISOGG Wiki, the relationship is almost certainly one of these: one of you is half-sibling of the other one of you is aunt or uncle of the other one of you is grandparent of the other one of you is double-first-cousin of the other Some ...


7

The ISOGG Wiki's article on Autosomal DNA statistics explains the concepts in the previous answer in much more detail -- and includes links to the AncestryDNA white paper that explains Ancestry's matching algorithm. Humans have 22 pairs of chromosomes plus the X/Y chromosomes. Assuming nothing went awry when the chromosomes were sorted out in the ...


7

The "DD"-prefix simply means that they're a member of the Facebook group "DNA Detectives". It's a Facebook group for people who use DNA genealogy to track down family members. If you're on Facebook, and join that group you can contact the person using the prefix who might then be able to help with your research. There's a handy little Genetic Genealogy ...


7

You're starting off with a doozy of a match. Yep, something's going on here. Let's start with the shared cM project. Looking at the total cM match only, your possibilities for a 1,193 cM match include: Great grandparent (range 464-1486) Grandparent (1156-2311) Half aunt/uncle (500-1446) Great aunt/uncle (251-2108) 1st cousin (553-1225) We can rule out ...


7

Absolutely not. The amount of saliva is a factor in whether or not you get DNA results at all. If you have them, that's it. While there is such a thing as "partial results" it's because you need multiple passes of the DNA sequence to make sure there aren't errors. No testing company will give you results if they don't get enough passes. A very small ...


7

DNA inheritance is very random in terms of how much DNA you get from each ancestor, due to genetic recombination. This basically means that although you get close to exactly 50% of your autosomal DNA from each parent, the amount you inherit from each grandparent, great grandparent, etc. will be different. I was able to test three of my grandparents and I ...


6

I am not an expert on DNA testing. But I learnt (and still learn) a lot through the story of Michael Lacopo at his blog "Hoosier Daddy?" where he blogs about how (tries) to find the biological father of his mother. And he gives a very important graph that shows how much DNA you and a given ancestor have in common (on average!): The smaller the numbers the ...


6

As a group of siblings, the set of your DNA results alone do not give very much leverage in narrowing down which ancestral branches can be excluded when trying to find an ancestor responsible for a DNA match with someone else. For the most part, the results from full siblings simply enlarge the set of DNA sequences available to match against others but do ...


6

The oldest answer has given a great overview of X inheritance, and I agree with what it says. It does take study to understand. Initially I suggest you mainly rely on Coakley's two main charts of X inheritance (one for a female descendant, one for a male descendant). The green boxes on those pedigrees show who could have carried the X segment you are ...


6

The closer your match generationally you will generally have more shared centimorgans (cMs). There is a published shared cM relationship range chart on the ISOGG website that gives a good general 'guideline' for interpretation.. ...but it is just a guideline as the further one gets out in relationship you may retrieve additional shared cMs from more than ...


6

The colored segments are not drawn in terms of cM, but in million base pairs (Mbp), which are the number shown on the bottom of your graphic. The numbers at the bottom are very approximate in position. So your purple segment is drawn between 102.9 and 111.0 Mbp and your green segment is drawn from 149.4 to 154.6 Mbp. So the purple segment is 8.1 Mbp long ...


6

Just a note that you should not automatically jump to the conclusion that you and your probably-half-sibling must share a father instead of a mother; young unmarried pregnant women were often pressured to give away their babies and never speak of it again. Your DNA results should be able to show whether you two specifically share an X chromosome match or ...


6

I will try to explain more comprehensively. What does phasing do and what task does it solve? We use phasing to separate the list of matches of one's person into two smaller lists of probable relatives: by paternal and maternal lines. Also phasing is great in terms of eliminating IBS (non-IBD) matches. Imagine that somebody has small DNA overlap with your ...


6

Edit: Brainstorm and I had an extended discussion through the comments on whether Visual Phasing of siblings can add information that the parent's DNA test doesn't already add. I have been convinced that yes, doing so can provide information not had by the parent alone. It is possible to phase the parents from the children with the additional help of ...


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