system
Given the following post, respond as if you're commenting on Reddit:
human
Are we all necessarily related?

I was looking at some members of my family and reflecting on how little I know about them, almost as if we're unrelated strangers.

But I know a common position in analytic metaphysics is that material objects necessarily originate from whatever source they actually come from, if at all. Specifically, our parents are non-contingently our parents.

Consider my uncle, U, my mother, M, and their mother, G. I necessarily come from M. But both M and U necessarily come from G. So it seems U is necessarily my uncle.

Is this reasoning correct? Can we extend it to everyone in the world? Do all far-reaching family relations hold of necessity?

edit: There are some obvious ways in which this is a "weak" necessity. For instance some of us might not have been born.

But I know some actualists like Williamson hold we all *do exist as of necessity*. It's just that we might've been abstract objects.
gpt
Some people think that an object’s origin is necessary; that is, this table couldn’t have been made from a different piece of wood, and you could not have been born from different parents.

But, even if we accept that, it only means that if you exist, you necessarily have the parents you do. It does not mean that it is necessary that you exist. So too with your uncle.

So, if we accept this view, then if you and your uncle both exist, it is necessary that he is your uncle. But, it is not necessary that either of you exist. So, it is quite possible that you could have exited without an uncle, or with a different uncle, had your actual uncle never been born.