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Comment by timoth3y | Hacker News Reader

They are not operating from the full DNA, but "enough DNA to piece together functional genomes."

However, even if we had pristine copies of mammoth DNA we could not re-create a mammoth.

Complex organisms like mammoths (or humans) are not fully defined by DNA. They are an ecosystem of bacteria and smaller organisms. We don't know the number for mammoths, but about 40% of the cells in the human body are not human. They don't have our DNA. Without them, however, we could not even process food. We get those organisms, not from DNA, but from other humans and the environment around us.

These scientists may be able to create something, and hopefully something that will not suffer horribly, but de-extinction is not nearing realty.

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You're ignoring the elephant in the room: frozen mammoth dung.

To restore the gut health of humans, there is this thing called "fecal transplant" [1]: use another person's poo to bootstrap the growth of your own gut microbiome.

There is an abundance of mammoth dung in the northern permafrost. When thawed, its microbiome becomes active again, producing methane. [2]

So resurrecting the woolly mammoth as a species is the hardest part. Equipping the first individuals with a proper gut biome will be really easy.

[1] https://en.wikipedia.org/wiki/Fecal_microbiota_transplant

[2] https://www.smithsonianmag.com/science-nature/melting-permaf...

Axenic (bacteria-free) mice (and other species) are bred and raised in labs everywhere and are not very different from wild mice, so while it could make a difference for a de-extinct mammoth, it may not.

OK. You sent me down a new rabbit hole. It was fun. Thank you for that!

It is really interesting that a mammal can survive without its fauna. The fact that it's possible at all is important.

Axenic mice, however, need to be bred and maintained in isolators and they need to be fed a carefully prepared diet to keep them alive.

In practice, particularly in the context of de-extinction, the overall point still stands. Having the DNA does not mean we can create a viable organism. Is an elephant's fauna "close enough" so the calf can pick it up from the mother and use it?

Maybe?

But we are looking at micro-organisms separated by 10,000 years and from two very different climates, so I'm not sure if the odds are favorable.

== Edit :spelling

Defining what is and isn't part of a species based on their gut microbiota seems nonsensical.

That would imply newborns start out as not human and then turn into humans when as they develop a gut biome and people that have distinct biomes are a separate species.

> Defining what is and isn't part of a species based on their gut microbiota seems nonsensical.

OP never said this. They said complex organisms are not fully defined solely by their DNA. That is a finer point than the one you're engaging with.

40% of the cells but much less of the mass: bacterial cells are much smaller.

The point is not how much they weigh, but that we can't survive without them.

It's not just the digestive tract. Our eyes, out lungs, even our skin rely on a huge diversity of specialized and symbiotic organisms to function correctly. This ecosystem evolved in parallel with our DNA, and it's been lost for the mammoth.

Yes, it seems we have the technology to create something with this DNA, but it won't be a mammoth as the organism existed in the past. It may not be viable, and it may suffer horribly.

Part of the point though was for some reason the number of them. If we didn't need the large amount in the digestive system but still needed it for lungs and eyes, looking at the number and saying it's only 1% wouldn't have any real implication for whether the offspring would be viable if it would have messed up lungs and not be.

Aside from that though, it may be important, but there are also lots of cross-species animals (ligers, mules, etc.) that don't get the full bacterial dose from the father of which half of their genetics come from and that doesn't seem to be a main cause of any of their problems that I've heard of.

Would borrow all this flora from their mothers without "suffering horribly".

Does that mean you are no longer human if you take antibiotics and kill the ecosystem of bacteria? I think there could be some legal loopholes there.

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