So the long skein of genealogy is spun
that ends in me. So is the history unrolled
that chronicles quiet, far from famous, lives,
each to itself important, as mine to me.
They are my people, blood-linked by marriage nets
spread across families of diverse kinds.
Their varied backgrounds, traits, abilities,
merge in my temperament as, within this earth,
by right of legacy, winters and summers lie -
the contrasts and the complements of life.

This is the last verse of a poem, "Scottish Legacy", by Katherine Sorley Walker. I think it's a fair description of the fascinations of genealogy, and explains its importance to some, myself for instance.
Now that I can write once more in a manner that doesn't resemble stream of consciousness I'll have another poetry season.
The whole of the above poem can be found, along with much else that is entertaining and thought-provoking, in "Modern Scottish Women Poets"(Dorthy McMillan and Michel Byrne, editors, 2003).