Paper trails and decades of research, what is the point?

[JAKnighton]

I know people will disagree strongly but I always feel if an ancestor is not a blood ancestor, then they are not a real ancestor, as they are not actually responsible for my existence, or anyone else thought to have descended from them.

What about a scenario where a non-blood ancestor decides to move his family to a completely different country? In that case, even if one or more of his children are not biologically his, his decision had a profound affect on all of their descendants.

Likewise, if your ancestor was fathered by an agricultural labourer, but raised by a blacksmith and adopted his trade, that would have a massive ripple effect on all of his descendants.

[pharmaT]

For me the point is that I enjoy the research, that is the point, a hobby for me.

If there turns out to be a non paternal event along the way I'd like to know, I'd add that to my research.  I see the research as more than just where my genes are from.  I see us all as a combination of nature and nurture so someone who raised an ancestor did have an impact on their life.

[Kevin Burrell]

I would be more worried if I found out that my 6 x great Grandfather was not related to me in a DNA test as it would potentially mean a complete rehash of the whole tree - not that I can go back that far unfortunately - my GGG grandfather was born in Ireland around 1785 and there are no online records before 1800 in Ireland (or at least the part I would be interested in) - sob!
Mind you I understand the doubt - I must do a DNA test just to see if my parents held anything back from me - or to confirm the Hospital did not mix up babies back in 1959!

[pharmaT]

It is possible to be descended from someone yet share no DNA with them.  The further back the greater the chance that has happened.  It is due to the randomness of inheritance.  Although we get 50% of our DNA from each parent it is random so not necessarily exactly 25% from each grandparent.  If this is multiplied back through multiple generations it leads to the chance of no shared DNA.

For 3x grt grandparents the chance of not inheriting any DNA from them is only 0.01% but by the time you get to 6xgrt grandparent, there is a 17.76% chance, by 10x grt grandparent the chance is 57.53%.  This also means for many ancestors you may inherit less than you'd have thought from a specific ancestor.

[coombs]

Yes, very true. Easy to assume the worst with DNA testing, but once you know how it is more and more likely to descend from someone by blood but not inherit any DNA from them the further back you go. Say for instance someone born 1970 and someone born 1755. I say the 1755 person is probably a 5xgreat grandfather of the person born 1970 if the link is autosomal (not either the paternal line or maternal line), so say the 1755 man to the 1970s man is his mothers, mothers, mothers, fathers mothers mothers father's father. Very unlikely you will have shared DNA with an ancestor that far back, on an autosomal line.

[Nanna52]

Coombs as someone who has a NPE in my ancestry.  Who cares?  I knew about it, at grandparent level, and did my dna because I’m a sticky beak and wanted to know who did it. 
Let me tell you, the blood line did not know where their beds were.  So many people I contacted had an NPE in their line.  It becomes a discussion of nature versus nurture.  In my case nurture was far more stable.

[kath davis]

Yes, Nanna52, who cares?  I would like to know who my great grandfather was, but my grandfather's mother did not want us to know, or the info would have come out somewhere I feel sure! I trust that she knew!

[Rosinish]

You're right, there's no point to it.

It's an interesting hobby though.

I wouldn't go to that extreme...

It's a bit like doing a jigsaw you want to frame & finding a crucial bit is missing, except, there's more chance of finding that missing piece of your family history via DNA than finding the missing jigsaw piece 

It's a hobby as well as an interest but always 'expect to find the unexpected' & finding unexpected things makes it more enjoyable & interesting...well...as long as it doesn't affect the 'here & now'!

My most enjoyable part of research & DNA matches is finding 'putative' fathers' names on marriage certs. etc. of illegitimate children in my tree & finding 'unknowns' with DNA matches which I eagerly await correspondence from but I don't worry or lose sleep wondering, I get frustrated they don't reply 

Annie

[Rena]

I initially started my research because I wanted to discover who in my family had died in a war zone during the Great War.  I discovered it had been my maternal grandmother's oldest brother.

Once I had made the discovery I didn't stop there because I found some lines passed down ailments, such as cancer, diabetes and seemingly arthritis, thus I wanted to confirm my suspicions and delved further back looking for death certs.

I think I probably fit into both categories of :-

(a) the hobby of family history, and
(b) genealogy = studying and tracing lines of descent.

I am not planning to have my DNA tested

P.S.  there is no better thrill than obtaining a hard to find document, that causes you to dance around the room with glee.