So who's your back plan?

During a conversation with an old friend. I was asked "who's your backup plan?" I said "Huh" and she clarified "Who do you have if you get too old and haven't gotten married or had kids yet?" I was surprised by how serious she was about that question, but before answering she tailed off into a series of complements that concluded with "You better not waste your genes." But anyway, the point of this is that I've heard this before from a few people in regardless to having an age cut-off point and a person or persons that would hypothetically be willing to get together if other things don't happen naturally.

Now I've heard this said in jest and I've heard from folks that were dead serious about it. So tell me, is this a legit concept that's out there for this generation so we don't "waste our genes?