> If I and all my descendants have 2 kids, by the 6th generation, there will be 64 people with 1.56% of my DNA, which adds up to one full person.
If 64 people drink 1.56% of a bottle of wine, it adds up to one drunk person.
At some point, a value turns insignificant.
To be clear: I am very much aware we do need kids, although a slight population shrink wouldn’t be too terrible. But people who tell themselves “the childless are removing themselves from the gene pool” are pulling wool over their own eyes if they think they are contributing all that much.
Life out there is everything but mere numbers and statistics. Having kids is not about just propagating genes, but raising another generation that will take care of this planet and mankind's future, or fuck it up further with stupid selfish approach.
You can have a say in this, a largely thankless say, but with kids we imprint ourselves and our values in mankind's future. Smart folks giving up on kids are removing smart genes from future gene pool, who then gets more diluted by illiterate farmers having 10-15 kids. Of course smart & broken ain't the same value proposition as smart & functional.
You don't have to care about any of this of course, that's highly individual. But raising kids well (which requires tremendous continuous effort with no guarantee of success) is extremely rewarding experience that no mere words or just brief encounters within friends/family can explain. I speak as participant of quite a few extreme mountain sports, which can be massively rewarding but there is just no comparison. To not have kids just because of chasing some career... no respect there, its a common story that brings some deep regrets later. Not to expect anything back, just doing something good, charity in a way. It requires certain character traits to appreciate, and ie selfish folks won't ever grok this part which then translates into what sort of parents they are and what sort of kids they raise, but its there.
Anyway its just smart folks discussing pros and cons of having kids while world and its population moves forward without any care of such topics. Life with no kids is like a computer game played on easy mode. Sure, some folks can't even finish nor enjoy it on higher difficulty, its just too much for them. But that higher difficulty brings much more rewarding experience, every achievement is much harder won one, and we all know challenges build & sustain good character. So there is some angle even for selfish folks (although yeah if even one recognizes oneself as selfish, having kids are probably not the brightest idea).
What if they all have an exact copy of the same 1.56% of you DNA and the rest is lost forever?
In reality .. A) it doesn't work that way and B) for the bit that does work that way it is as unlikely for the same 1/64 "fingerprint" to be all that is shared as it is for a complete "fingerprint" to be exactly split into 64 parts, each to one of 64 descendants.
The only purpose to life is to propagate more life. Anything else we might attribute to life is simply a coping mechanism for this abyssal vapidity.
Life also selects for more life, for the obvious reason.
Marriage-less and/or childless people hold no equity in the future and will be naturally selected out for those who do. The birth rate "problem" will resolve itself.
Note for context: I'm 35, never married nor intend to and never had nor intend to have children. I hold no equity in the future and I sincerely couldn't care less; I'm busy living as it is.
By the 6th generation of offspring, there is only ~1.56% left of “you”. 200 years is the blink of an eye, historically speaking.
If you yearn for legacy.. be a writer, teacher, researcher. Zeno is passing on his thinking some 2400 years after his death.