"Too" Much to be "Noise"?

[awtx903]

I am new to the world of genetics & DNA. Having no formal education or prior experience. Please pardon my ignorance in advance.

The admixture analyses of my autosomal DNA test results, performed by GEDmatch, suggests the following:
 

E_Eurasian: 2.83%
Sub-Saharan African: 1.96%

W_Eurasian: 95.21%

 

My first question...would/could this 1.96% SSA be considered as “noise”? On my chromosome painting, there is a SIGNIFICANT showing of Sub-Saharan on Chr 8.

 

My second question...would/could/does this indicate an African ancestor hiding somewhere in my family tree?

With familial roots in the deep “South”, United States, for the last 200/300 years, I would not be surprised…

Thoughts?

Thank you in advance.

[CharonY]

In general it must be stated that many of the ancestry tests are problematic, often yielding non-reproducible results for whatever reasons (most strikingly are identical twins getting different results, there are quite a few articles out there about these issues and typically services also state them). A related issue is that the calculations will highly depend on the information in their respective database. As a general comment, obviously if we go back enough, all our ancestry comes from African populations eventually. But obviously the database compare it to entries of existing populations.

So to somewhat address your question, it is possible that somewhat somewhere you have had a relative that was mostly Sub-Saharan in their genetic makeup. However, it is also possible that you had folks in your ancestry that just happened to carry those markers whilst not appearing to be particularly African. The deeper you want to dig the less accurate predictions become, essentially. Another thing of note is that the DNA only shows you what you eventually have inherited. I.e. it is for example perfectly possible that you actually have a sub-Saharan ancestor somewhat way back, but just by chance you only inherited mostly parts from them that are highly conserved between populations (i.e. so similar that they cannot be used to distinguish between groups). Conversely, elements may be missing because just by chance you did not inherit any distinguishing markers from them.