Tuesday 6 June 2023

End Of Line? It's Terminal.

Are you the last of your lineage? After you, no more <insert family name here> running around the yard? No more <insert family tree name here> DNA in the world? 

Don't be too discouraged and don't feel too guilty. We share more DNA with other humans than we do with molluscs or mushrooms, but the variation in our genotype is only about 0.1%. While that means that our particular genome will end with us, the rest of our unique DNA is spread out among billions of other humans. 

So we're not really denying the gene pool of too much mixing. We think there have been only around 108bn home sapiens born on the planet since the species diverged from the hominid branch. There will soon be 9bn of us on the planet at a time, so maybe around 7-8% of all the h. sapiens that ever lived are here on the planet right now. Even if that figure was closer to 4% that's still a pretty large gene pool. It can do without contributions from some of us.

Don't Worry, Others Have Worried For You.

Starre Vartan had this same question in mind. (For podcast listeners - the link will be in the article when it's published.

And I had this question in mind when I decided I'd be an endling. (An "endling" is technically the last of a distinct species but the same concept applies to DNA of a family tree I think.) And actually - technically - I'd only be an endling of this branch of the <insert family tree name here> family tree. But I have female siblings and now quite a few nieces and nephews so their DNA contribution will outlive me.

There are also so many other things tied up in this. For one, why do we have this implacable drive to have our DNA be propagated into the future? Are we really the fittest h. sapiens that ever lived? Some people in history thought so - the eugenicists. "Terminate all inferior bloodlines, only the One True Race!" but that's just so much hokum. 

Because when you press any eugenicist to imagine the point where only their race exists on the planet with numbers approaching 9 billion, and ask them what this Superior Race will look like, it turns out they all look like that eugenicist. "Only Skwarkians with straight spines, brown eyes, three nipples, fine (but not too fine) musculature, a height of 180cm, and thick protective hair on their head!" they exclaim, and they're describing only themselves. 

When it comes down to a point where you've subdivided Skwarkians into 27 sub-races, only one will do. When you divide that last 1/27th into your family and the other 80,000 families, only YOUR family meets the standard. And then, do you know what you get? Have you got there yet? You get in-breeding, that's what you get. 

Imagine a time in the unimaginably far distant future when humans can instantaneously move wherever in the Universe they want and can form breeding unions with whomever they want, and the number of humans alive at any one time has so many zeroes after it that it's staggeringly close to the number of all planets. And the matter of "whomever they want" becomes inconsequential because there aren't any more variations possible of that 0.1% of the DNA... 

Slight Hiccup:

There may be a genetic predisposition component to not wanting to have kids. (The old joke "If your parents never had sex, chances are you won't either" comes to mind.) But truly - if there's a slight genetic variation that predisposes a person to not procreating, then that's a trait that will obviously breed itself out. 

But that's okay too. It means that the eager breeders will breed, meaning that again, your action (in not adding to the gene pool) won't affect the viability of the species. We family endlings have the best of both worlds. The hiccup turns out to not be an issue either. 

On A Personal Note

I decided, as I said, to not have kids. A lot of things. I could never imagine me with a young'un, I mean, a pup was already a huge commitment... I couldn't imagine raising a small human and teaching them al about life - if I wanted that I'd have become a teacher I suppose - in the climate of uncertainty that was already evident when I was a parenting age. 

And if you've decided you'd prefer to make our population growth figures a bit less frenetic, don't worry. Everything will work out just fine. 

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