If you're interested in ancestors back in the 1700's, you probably have more than 200 direct ancestors (2*2*2*2 etc.). Some of those may not be genetic ancestors; adoption or placing children with other families was more common back when, but the majority of them are genetically related.

If you following a single line, say your patrilineal as I do (MacBean), then only one out of the 200-300 other ancestors of that time shared the name. Genetically, we are far more mixed than we realize, no matter where on earth we live; that's what makes sexual reproduction so valuable biologically...it guarantees mixing.

But perhaps you are seeking meaning, a story or two, a sense of identity. Those are completely under your control, are your choice and yours alone. Some here make no pretence of being Scottish...no matter. Others are sure they're Scottish, but I doubt that stands much scrutiny. We are all mixed.

My twopence...