Ancestry Matches and Half Cousins.

[BristolClark]

I have had a tentaive search online, and a search through threads on here, but haven't come across an answer that makes my confusion any clearer. So apologies if creating the 1001st thread asking this.

The query I have is in regards to Ancestry matches and 'common ancestors.'

I have a handful of matches where we only descend from one ancestor rather than two.
For example, a female 4xgreat-Grandmother by Ancestry has myself and a "half cousin" being descended from her only, and not also the male 4xgreat-Grandfather.
There is no before or after marriages, as they were married young and died still together years later.

Does this indicate a non paternal issue, or a slight on Ancestry's part figuring out a relationship?

[Pheno]

It occurs mostly where some of the other trees from which Ancestry is taking its thrulines have:
a) only got one half of the couple in their tree
2) both people are there but not spelt in exactly the same way as you have so Ancestry is unsure whether they are the same people

Pheno

[Rosinish]

You would be better going by the amount of cMs, % (Percentage) & Segments to try & determine the relationship with your match & any Shared Matches.

It may be worth trying the LEEDS Method...

https://www.yourdnaguide.com/leeds-method

Annie

[brigidmac]

You are talking about matching on thu lines here : 

First Check if their trees have the same siblings and father as you  have for that ancestor

Next check for different spellings .
 You can't get them to change spellings but you can temporarily change yours ie from Henry to Harry to match theirs and add a comment that appears in white box on his profile such as baptised as Henry appears as Harry on marriage * you can change it back to your preferred spelling a few weeks later when you and they have had chance to see new thru line *also you can add relationship yourself as mother's side 4th cousin.which overides the thru line suggested relationship and the matches suggested relationship 3-5th cousin

Have you or any of your matches added anything in suffix box to that ggfather .

Some people add 3xggfather or Mr or captain

So the computer thinks it's a different person

Or if they put  alternative names and use brackets or dashes

John/Jack
Harry (Henry)
Will look like different people to plain John or Henry

If you use the name John you can show jack as a middle name and ancestry will probably match with those who have put just John or just jack but not the one with brackets

If you contact any of your matches encourage them to use tag functions for direct ancestors
And also known as for alternative spellings and nicknames .

Does that help ?

[brigidmac]

Modified and added to last post  hopefully to make it clearer .

Also if you add a photo or clip of a document to YOUR  ancestor s profile

They will be able to check  if they have correct person you can also add a comment in the gallery to say that thru lines are t showing to Harry/Henry the 4th on other trees and explain why

...some matches and non matches may copy  this pic ..even those with private trees ..I find it's a good way to contact people. " I see you have added ggfather Henry's document to your tree ..we must be related .if you remove punctuation from his profile our thru lines will appear .

[Albufera32]

When I first took the DNA test a couple of years ago, whilst waiting for the results to return I watched a several online videos about the use of DNA in genealogical research, including a number from Christa Cowan at Ancestry. I found them very useful, not least because they highlighted a number of things I was not aware of, nor would have ever suspected.

One of the ones that I found most surprising is that by default Ancestry uses the genealogical standard format for dates, (ie dates in the form 22 Sep 2022). Not that it is surprising that a genealogical programme using the standard genealogical format (though ironically the "British" Find my Past does not). What was surprising to me at least, was that most importantly she stressed that any other format can, as she put it, "confuse" the algorithm they use, not just in cases like 5/12/22 (is it 12th May or 5th Dec) but even for example 22 SEPTEMBER 2022 or even 22nd Sep 2022.

Another thing that she stresses is that Thrulines are essentially HINTS. The way the thrulines are formed is VERY similar to the way your hints are gathered - Ancestry compares trees looking for people with the same names, dates, locations etc as in your tree in other people's trees. The consequence of this can indeed be that because the other tree may well have a different person listed as your direct Ancestor's spouse, it may consider that person as a "half cousin" when they should in fact be a full cousin. I have one instance for example where EVERYTHING in my tree and another matches tree is the same, right up to the two common Ancestors, but a third tree has the wife born 50 miles away based on finding a "Sarah" on the 1841 census. Based on that, thrulines insists that my Grandfather William Howie, the minister of Dunoon Parish who died in 1929 has a half something cousin called William Howie who was the minister of Dunoon Parish and died in 1929.

[Guy Etchells]

I have had a tentaive search online, and a search through threads on here, but haven't come across an answer that makes my confusion any clearer. So apologies if creating the 1001st thread asking this.

The query I have is in regards to Ancestry matches and 'common ancestors.'

I have a handful of matches where we only descend from one ancestor rather than two.
For example, a female 4xgreat-Grandmother by Ancestry has myself and a "half cousin" being descended from her only, and not also the male 4xgreat-Grandfather.
There is no before or after marriages, as they were married young and died still together years later.

Does this indicate a non paternal issue, or a slight on Ancestry's part figuring out a relationship?

I do not understand your question. Do you mean you are not a DNA match to the spouse of the shown ancestor or are you simply referring to paper trail research and other people's trees?
If the first (DNA) it should be remembered that each parent only provides approximately 50% of their child's DNA (in addition a Small proportion of the child's DNA is "background" DNA which most of the population of the area carry).
Each parent in every generation that passes only passes down approximately 50% of their DNA so by simple arithmetic a child would on average only have 1.5% of any particular 4th grt. grandparent's DNA in their DNA and it is possible may not have any identifyable amount of DNA from that grt. grandparent showing in their DNA.
Cheers
Guy

[Albufera32]

I think they are referring to Thrulines allocating a match as a "half cousin" rather than full cousin, in cases where their tree or paper trail suggests it is in fact a full cousin relationship.

[Biggles50]

Thrulines are based on the trees on Ancestry.

We all know just how cobbled together many Ancestry trees are and thenpotential for multiple errors are very significant.

Thrulines imo are best viewed as and actioned as Hints that need to be thoroughly validated person by person.

Yes a half match is very possible, I have found many such occurrences.

Common Ancestors have resulted in many additions to our trees but within each one each suggested person has been thoroughly checked.  There have been many errors and quite a few missing generations.