Slugs have evolved multiple times from snails, due to calcium poverty, dividing off into separate species when they couldn't get the resources for shells
One person you're destined for by a grand design of the universe? No.
Someone you connect with on a deep level that goes beyond rational considerations and even emotional sensations? Yes, absolutely.
This is why it's possible to meet more than one in a lifetime. Timing is also a big part of it, I've met half a dozen people over the last thirty years who I would have spent my life with, where I was in my life at the time made all the difference of how those relationships played out.
That certainly a strong theme in many moral systems although it's not a universality, as evidenced by the number of justifications people have come up with over human history to hurt other people
Today I learnt my sexuality is USB