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Comment by gumby | Hacker News Reader

And, according to the article, it's not just lucky that we survived that, but that very bottleneck could have itself produced H. Hiedelbergensis, and thus H. Sapiens Sapiens.

Which also implies that while one remote group could have shrunk to a colony of about 1,300 hominids and leading to us, elsewhere other species of humans could have survived just fine for longer, later dying out due to other exogenous pressure, perhaps from our closer ancestors.

I have read that the world's cheetah are so genetically similar that they appear to have suffered two population bottlenecks, the recent one being only 10-12Ky ago in which the population might have shrunk as low as 30-40 cheetahs.

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Fun fact about cheetahs is that they’re so interrelated that any cheetah can accept a skin graft from nearly any other cheetah. They’re so similar that their immune system can’t recognize that the transplanted skin is from a different individual

Got a source for that? It sounds fascinating

Yep, here’s the 1985 study where they tested reciprocal skin grafts across 14 unrelated cheetahs.

Genetics research before easy sequencing was super wild.

https://pubmed.ncbi.nlm.nih.gov/2983425/

If that's true then maybe we could graft whole cheetahs together to form Cheetah Voltron.

Maybe you can but please consider, first, whether you should.

Oh, good point. I should reconsider my totally serious and not at all facetious plans to build a giant humanoid robot out of savannah cats.

thank you.

That's all I want to hear. It would be a shame if something went horribly wrong with your cheetah-mech theme park.

Yeah but... what IF it all went right? :D

How fast could a 6 legged cheetah run?

I'm assuming not at all unless you were really, really good at building Cheetah-based abominations.

Irish Wolfhounds have been brought back through outbreeding, I wonder if the same would hold for them.

> might have shrunk as low as 30-40 cheetahs

Or, at one point a mutation, or a group of mutations, gave rise to a small number of super-cheetahs that interbred, and those cheetahs completely out-competed all other cheetahs.

Or, more likely, at one point a mutation, or a group of mutations, gave rise to a small number of super-cheetahs that interbred, and those cheetahs completely out-competed all other cheetahs until the remaining standard cheetahs, that had been enslaved rebelled under the cheetah Spartacus, overwhelming and eradicating the super-cheetahs using the super-cheetah's own aircraft and other weapons, though even in victory leaving only a small number of normal ones to continue the species.

Ockham's razor says my scenario is more likely.

lol, have an upvote.

I am Cheetahcus!

The Third Feline Servile war was a very dangerous time indeed

There do seem to be some evolutionary branch points in which a single occurrence of a mutation or adaptation seems to have proven overwhelmingly successful.

The one I'm most familiar with is of the integration of mitochondria into eukaryotic cells. My understanding is that all mitochondria seem to trace to a common ancestor, which would suggest that this mutation appeared once, and was so overwhelmingly energetically advantageous that all eukaryotic life descended from that single individual.

(There are non-mitochondrial life forms, including prokaryotic bacteria. But so far as I'm aware every complex multicellular life form, and quite a few unicellular ones, are all prokaryotes.)

There are many such captures, for example the cilia of ciliates or the flagellum of flagella.

By captures, you're referring to incorporation of one species within another?

That's not the point I'm emphasizing here. It's the overwhelming metabolic advantage afforded by mitochondrial ATP respiration.

Of that, it seems only one variant has survived. It either emerged only once, or out-competed all prior and subsequent emergences.

They even made a videogame about that, the cheetahmen.

There is no "Or, ".

The bottleneck consists in the fact that the present cheetahs are the descendants of a group of 30-40 cheetahs that have lived at a certain time.

There are multiple possible explanations for why the bottleneck happened.

There might have been a climate change or another abiotic cause that has killed the other cheetahs, there might have been a disease that has killed the other cheetahs, their prey might have disappeared, another predator, like lions or hyenas might have killed most of them, and so on.

Among the possible causes, both in this case and in the case of humans, there is also the possibility that there has been, as you say, some mutation that has given to a small group an unusually important advantage, allowing them to outcompete any other cheetahs, so in time only their descendants have survived while the descendants of any other cheetahs have disappeared.

In the case of cheetahs, such a cause for the apparent bottleneck seems much less likely than in the case of humans, because it is hard to imagine a decisive advantage of the mutated cheetahs. Something like one extra meter per second in maximum speed does not seem to give enough advantage over competing predators.

What are you describing is one possible explanation for how a bottleneck happened, but your scenario would still result in a genetic bottleneck.

That explains why cheetahs never prosper

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