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JBee
30-08-20, 14:11
According to ancestry my son's dna results are:-

1st cousin

My half sister with 787cm over 30 segments is a 1st cousin
Her/my niece with 706cm over 18 segments is also a 1st cousin

2nd Cousin

My half sister's son/ my half nephew has 412 cm over 20 segments
- a lot less than his full cousin.
.................................................. ......

Now how significant is it the number of segments?

Most of the results are 1 or 2 segments and 4th cousins

but now I have found a match of 36cm over 6 segments a 4th - 6th cousin? As there's no tree I can't fathom out where she fits in except by seeing which family she shares matches with.

kiterunner
30-08-20, 18:42
The number of segments doesn't mean much. The number of centimorgans is much more important.

JBee
30-08-20, 19:34
Thanks Kite

However why does my half sister's son only have 412cms whereas my half brother's daughter has 706cm.

kiterunner
30-08-20, 20:00
Both values have half 1st cousin as a possible if you feed them in on DNA Painter (link below). It's just that by chance he has inherited more of the same DNA as one of them than the other.

https://dnapainter.com/tools/sharedcmv4

JBee
30-08-20, 23:18
Thanks Kate

This DNA lark really confuses me.

ElizabethHerts
31-08-20, 10:07
I'm confused too, Julie!

Does this make sense (for a family member):

Predicted relationship: 4th–6th Cousin

Shared DNA: 23 cM across 1 segments
Longest Segment: 30 cM

kiterunner
31-08-20, 10:59
Yes, it makes sense. The longest segment data is from before their application of the Timber algorithm, and the amount of shared DNA is from after it.

ElizabethHerts
31-08-20, 11:01
Thanks, Kate. I really need to do a week's course in DNA when I have time!

kiterunner
31-08-20, 12:09
There was a family history conference / show due to be held earlier this year which was cancelled, and they had various lectures you could opt for, including a few on what to do with your DNA matches. Those were all booked up very quickly (the cancellation must have been disappointing for the people who booked), but I don't know whether they ever did them online for people to watch from home instead. They could be pretty useful.

Phoenix
31-08-20, 12:53
I have problems when it says something like:

Shared DNA: 30 cM across 1 segments
Longest Segment: 23 cM

I assume that means it includes masses of crumbs, none of them adding up to a segment?

kiterunner
31-08-20, 14:39
I haven't seen one of those. I don't know what that would mean.

Phoenix
01-09-20, 15:10
Ah ha: "In some cases, the length of the longest shared segment is greater than the total length of shared DNA. This is because we adjust the length of shared DNA to reflect DNA that is most likely shared from a recent ancestor."

Not that I really understand.

kiterunner
01-09-20, 15:36
Yes, I understand it that way round, Phoenix, I just don't know how there could be one segment which is longer than the longest segment like in your post #10.