I don't much resemble my parents, nor the members of their families, nor, indeed, people outside their families. When I was younger I used to create conversational openings that would allow older relatives to reveal the secret of my origin, but, alas, they never did, so I am forced to operate as if my birth certificate is accurate.
I should add that even though I don't think I look like anyone, I am fairly frequently approached by strangers who feel the need to inform me I look JUST LIKE a friend or relative of theirs.