Ancestry removing matches less than 8cM

[LizzieL]

I've got several in that group - all with LS 49, fine for the closest two - both 1C1R and 546/16 and 412/20, but the others are 36/1, 34/1, 28/3, 31/2, 21/1 and of course CF at 34/3. I'll look at other groups where I know they've uploaded to Gedmatch, to see if anything makes any sense

[Gadget]

I've just found this from them:

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. Sometimes, DNA can be shared for reasons other than recent ancestry, such as when two people share the same ethnicity or are from the same regions.

[LizzieL]

I've just found this from them:

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. Sometimes, DNA can be shared for reasons other than recent ancestry, such as when two people share the same ethnicity or are from the same regions.

So the longest segment could be something ancestry has made up? still doesn't make sense to me

[lisalisa]

an example of the longest being longer which I've just been looking at

dna match to my mom 47 acr 2  longest 65
                to me 39 acr 1 longest 59

relationship is 1/2 4C and 1/2 4C1R

maybe the longest segment will be the 'more accurate' guide where the number of segments is low (if it is the shared which has been adjusted as they appear to be saying), however, it looks like the figures are still in the same ball park for connections.

[Romilly]

I've just found this from them:

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. Sometimes, DNA can be shared for reasons other than recent ancestry, such as when two people share the same ethnicity or are from the same regions.

I’ve been puzzling over this...?

Some of my ‘longest segments’ are twice the size of the DNA Ancestry says is shared! How can that be?

Romilly 

[Gadget]

As it says!

Ancestry have always cut off  a few  cMs because they think it might be inheritance by locality.  That's why the shared DNA is larger on My Heritage and Gedmatch for, for example.  There are a few threads on it.

[LizzieL]

Why can't they just show us the real results, not adjusted to what they think they might be.

[Gadget]

A quick example:

I have a known relative  -

Ancestry - 120 over 6 segs, largest segment 47cMs
My Heritage  - 133.4 over 7segs, largest segment 48.6cMs

Ancestry's algorithm  chopped off some. We all know what algorithms can do!

[Gadget]

Just found another one:

Ancestry - 48 over 2, largest seg   58
My Heritage  - 69.9 over 3, largest seg 57.6