DNA Concepts for Genealogy: Autosomal DNA
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- Опубликовано: 26 июл 2024
- A quick introduction to Autosomal DNA. Topics include the underlying genetics, how much DNA you share with relatives, how people analyze their matches (at a very high level), ethnicity reports and health reports, and links to additional resources. (CLICK TO READ MORE)
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Hi i look like genetically to my grandfather it is mean that i get more dna from my grandfather than other grandparents?
Not necessarily. Assuming it's not just coincidence that you look more like that grandfather, it would just mean that you inherited certain traits of his appearance. Most of our DNA doesn't affect how we look.
Hello am i sharing my dna with my all great greatparents?
You should have some DNA from all of your great-grandparents, yes. Normally about 12% of your DNA should be from each of your great-grandparents, but DNA is not perfectly inherited at exactly 50% from each parent in every generation, so over time there can be a range of how much DNA you inherit from each generation. The Shared cM Project (dnapainter.com/tools/sharedcmv4) studies the range of inheritance of actual testers and the smallest amount of DNA inherited from a great-grandparent seems to be about 6.5%. So you always inherit some, but sometimes not very much.
Once you go back more generations than that though it is possible that you have inherited NO DNA from certain great-great-grandparents and the odds get higher in subsequent earlier generations.
@@DaveVance01 It is rare that I don't get dna from all my greatgreat-grandparents
If my great great great grandfather only had one child, my great great grandfather, my great great great grandfather would not show up as a common ancestor with anyone else, correct? I mean if my gg grandfather had no siblings, there would be no cousins having his father as a common ancestor with me. I am trying to find the parents of my great great grandfather Edward Kelly without any luck so far. I think his biological father died soon after Edward's birth and he was raised by a stepfather and had half brothers but no full brothers. I do not know for sure, but I believe that his mother's name was Anna, but I don't know her maiden name, so I am stuck trying to find her parents as well. How can I find my great great great grandparents using my DNA matches if none of them seem to have any Kelly connections or connections to the stepbrothers surname of Lewis? One interesting side note is that I used the color coding of groups and came up with one group that has no apparent connection to any of the surnames anywhere in my tree. Is that normal? Could they be the elusive Kelly's or Lewis' or Edward's mother's family since I don't know her maiden name?
aworkinprogress2 I would post this question on the Genetic Genealogy Tips and Techniques group on Facebook. But from my point of view if your G-G-grandfather was an only child, he might still have first or even second cousins whose descendants could still show up as matches with small amounts of shared autosomal segments. With autosomal DNA testing you typically can only look back between 5 and 8 generations, so you have the possibility as well that current testers DO descend from these lines but don’t share any DNA (or not enough to show up as confirmed matches).
Having a DNA connection with a group that you can’t find a genealogical connection is pretty common; with autosomal the connection might be through maternal lines where the surnames have changed several times, or someone might even have changed their surname through an adoption etc.
Does Edward Kelly have any male Kelly descendants alive today? I’m thinking perhaps a Y-DNA test on a paternal descendant (all males passing along the same Y-DNA) from Edward might help you connect with at least his father’s line, and if you find any Y-DNA matches from further back that might help you locate at least the older ancestors of this line, and then work forwards in time to Edward’s father.
@@DaveVance01 Thank you.
Are we related to All our ancestors i mean 4 5 generation are we genetically related to all of them?
At about 4 or 5 generations you should normally inherit some DNA from all your ancestors so normally yes you would be genetically related to all of them. At 5 generations that can change though.
Starting at about 5 generations obviously you are still descended from your ancestors, but you would normally inherit only about 3% of your DNA from each of those 32 ancestors anyway so the pieces of DNA that you might inherit get very small, so small that sometimes an ancestor's DNA might not reach you at all or be so small that it can't be distinguished from "noise". As you go back further than 5 generations, the chances that you inherited no DNA from certain ancestral lines gets higher.
So generally at about 5-8 generations back you are not genetically related to ALL those ancestors, but it varies by person and the particular recombination of DNA that has taken place over those generations.
In other words, who you descend from and who you inherited DNA from are not the same group. You inherited DNA from a much smaller set of the people that you descend from.
@@DaveVance01 Max 4 generations am related to all of them true?
@@omet9991 Yes although it's possible for some people to have DNA from all ancestors at 5 or even 6 generations I believe, just less and less common. However 4 generations is the maximum that you can be sure that you have DNA from all of your ancestors.
Thank you (: