DNA Match for Thickies

[LeedsHipPriest69]

I had my DNA tested a few years ago and frankly thought it a waste of money other than being "fun" to see your origins

Can anyone explain in a way science thickies, I'm more a numbers person, can understand

I have a confirmed ancestor Joseph Benn (3rd gt grandfather). He died in 1843 supposedly aged 46 (buried in Leeds but likely born in Bradford). He married Rebecca Senior in Batley in 1822. All this makes him born circa 1797. I can't however confirm his parentage, I initially thought of Joshua Benn (of Great Horton) and Ann Blamiers (of Bradford) who married in 1793

Anyhow, according to Ancestry DNA Match, Joshua and Ann have a DNA match.

Joseph and Rebecca have a 21-50 cm match with me
Joshua and Ann 8-50 cm match
It then goes on to add that Joshua Benn and Mary Wilkinson, the above Joshua's parents, have a 8-37 cm match

Firstly what does this cm match mean (in plain english), and secondly is it suggesting these names simply because other Ancestry users have taken as fact the above lineage to be correct, inspite of no confirmed baptism for Joseph?

[Biggles50]

Read all the posts in this thread.

https://www.rootschat.com/forum/index.php?topic=863488.0

The cM refers to the amount of DNA that is shared between you and your DNA Match, it is the unit of centimorgans.

You inherit about 3485 cM from each of your parents.

1754 cM from each Grandparent

887 cM from each Great Grandparent

You share 886 cM with a First Cousin

You share 229 cM with a Second Cousin

You share 73 cM with a Third Cousin

Etc

The above are Mean values within a possible range of values.

By the time you get to 3x and 4x Great Grandparents you may not have inherited any of their DNA but siblings might have or vica versa.

Finally do not rely on any DNA test to give you an accurate Admixture, you will find that the results you have originally had will more than likely be very different today, such is the way Ancestry et al process the data and the vast increase in DNA testing uptake.

[TonyV]

Hi. Biggles50 has dealt with the basics but if I read your post correctly you are suggesting that relatives who are far too old to have taken a DNA test are matched to you. That is not possible. You can only be matched to people who have taken a test i.e. basically living people. Autosomal tests have been around for several years and typically if you tested today you might have several thousand matches on both sides of your family. As Biggles50 explained, the higher the centimorgan number the closer related you are to the match (as usual with such things there are some exceptions but they're not worth discussing at this level). The ethnicity part of your result may or may not be useful, the science is still developing, but the match side can be very useful as you try to break down brick walls.

Your DNA results however have to be used in conjunction with conventional genealogical research using all sorts of records, and I can see that you are into that already. The trick is to try to work out how your matches fit into your family and if they have attached trees, that's the place to start. If you can make the fit you may then see other parts of their tree that enable you to go back farther, or answer the kind of questions you referred to.

There is a wealth of help out there and far too much to explain in just one reply, but Biggles50 has given you a "starter for 10". I am neither scientific nor particularly numerate but there is a lot about DNA that is readily accessible if you take the time to read all the stuff out there.

Tony

 

[Ruskie]

I think the previous two replies have probably answered your question, but to answer simply, you can’t have a DNA match to dead people (who have not taken a DNA test). You can’t know how many cMs you match with dead people.

It sounds like you have taken this information from DNA matches’ trees on Ancestry?

I think your last paragraph sums it up, and they may have made assumptions about parentage. Have you contacted the tree owner/s to ask if they have any documentation?

If you have a DNA match to the tree owner, and some names in common, you obviously have a connection there, so it sounds like it’s their tree you need to confirm. Keep in mind that some trees online are incorrect or have been copied from others.

[Biggles50]

To emphasise.

DNA testing with Ancestry started in the US in 2012 and in the UK in 2015.

You can only have DNA Matches to people who themselves have taken an Ancestry test in the Countries that sell them.

If you have say a DNA match of 100 cM to yourself you can interpolate what DNA you share with the DNA Match’s parent and with their parent but this would be “ball park” guesses only.

If you wish to learn accurately about DNA then Future Learn have a free course and books are readily available, I specifically suggest one by Blaine T Bettinger as it is easy to follow.

[DavidG02]

I do think everyone has explained it but  my own personal experience might also be helpful

One of the reasons I wanted to take an autosomal test was to check on family whispers - do we have indigenous bloodlines , is my father someone elses child and just a curiosity to discover who I am connected to

On the issue of my father - he is indeed my grandfathers son - matched to close relatives here in Oz

But I have a match with someone who is a match to the sister of my GGGgrandmother Elizabeth Swannell - like you its easier to use the short cut '' I have a DNA match to my GGGG '' but more correctly '' I have a match to someone who the paper trail connects to us both sharing a GGGG ''