The deeper under the Earth's surface, the more species you can find | Hacker News Reader

The deeper under the Earth's surface, the more species you can find

arstechnica.com

46 pointspseudolus20 comments

This is pretty interesting: https://en.wikipedia.org/wiki/Deep_biosphere

"he biomass in the deep subsurface is about 15% of the total for the biosphere"

I'd bet that it's a higher percentage. That 15% represents what we have already found. There is likely more at greater depths we haven't found, and perhaps other types of life we aren't yet recognizing yet (a parallel to finding Archaea),

Scientists aren't just finding biomass, stating that as the figure for the total, and adding to it. 15% will be an estimate with variance as stated by a predictive model. We have found fractions of a per cent, with 15% being a predicted upper limit.

The 1993 NYT article has

>Assuming that three miles was the limit, and that only 1 percent of the total pore space available in the rocky crust was occupied by microbes, then the total mass of living material there would be about 200 trillion tons. If that material were spread over all the Earth's land surfaces, Dr. Gold wrote, the global layer of microbial sludge would be nearly five feet thick. "This would indeed be more than the existing surface flora and fauna,"...(https://www.nytimes.com/1993/12/28/science/strange-new-micro...)

Bringing a serious drill to Mars to check for life deep in the ground is a very important project!

We'll have to train a team of drillers to be astronauts. Those nerds at NASA what with all their math and charts don't know shit about drillin!

https://www.youtube.com/watch?v=73cWfFEKAfE

I have just the song to accompany the launch.

Musk:

>The first Starships to Mars will launch in 2 years when the next Earth-Mars transfer window opens. These will be uncrewed to test the reliability of landing intact on Mars.

I vote they stick a remote operated drilling rig in there.

Do we know how these microbes moved into these environments? Any idea if it was "surface water to underground" or the reverse? Microbes falling into a rift and moving sideways like cave dwellers taking up residence in a cave and adapting over generations?

It’s been known for quite a while that most life actually generated from the deep and then seated upwards. Photosynthesis came well after these creatures.

In his book "The Deep Hot Biosphere" Thomas Gold argued that life probably originated deep underground. Gold is a pretty controversial figure, but this hypothesis makes sense for a number of reasons: the underground environment is a lot more stable than the surface, and the chemistry to extract energy from the chemicals in that environment is a lot simpler than the chemistry to extract energy from sunlight. So it makes sense that underground chemosynthesis would emerge before photosynthesis.

Gold seemed an interesting character - I was just reading his Wikipedia.

The WaPo article on him is good

>As an astronomer and geophysicist, he says, "it always seemed absurd to me to see petroleum hydrocarbons on other planets, where there was obviously never any vegetation, even as we insist that on Earth they must be biological in origin." https://www.washingtonpost.com/wp-srv/style/features/daily/h...

I would expect diversity to decrease with diffusion rate, so e.g. diversity in soil or mud would be lower than diversity in water.

Would be more about total energy

The article says otherwise:

> even at depths where the energy supply is orders of magnitude lower than enjoyed by organisms in habitats that see the sun

> Something unexpected that caught Ruff’s attention was how total diversity went up with depth. This was surprising because less energy is available at deeper levels of the subsurface. For archaea, diversity went up with the increase in depth in terrestrial environments but not marine environments. The same happened with bacteria, except in marine instead of terrestrial environments.

I wonder if fewer reliable energy gradients means hyperspecialization around smaller niches.

that and collaboration between different very specialized micro organisms

Also a additional "wild" theory (from me, wield as in not properly researched/fact based):

Mono cultures or quasi monopolization of resources of one species rarely survive long term in nature (as in either they kill themself or them or the situation changes enough to remove the "monopoly". And if you go very deep underground you have increasing slower interchange/mixing between localities, and in general live is slower acting (to preserve energy). So over fit species (which risk themself due to monopolization) might in such bioms die out or fix themself before they can widely spread.

I imagine this could have more to do with how isolated these environments are?

There are more unique species on mountains or islands because it is hard for those species to leave and take over new territory. On the contrary, something on continental land or ocean can expand huge distances if it has new adaptation.

Just my amateur speculation, but I would imagine underground caves are very isolated from other caves even relatively close in terms of distance.

Gears of war, anyone ?

From the abstract, "Diversity of terrestrial microbiomes decreases with depth..."

Decreases. Gets smaller.

That is a copy and paste from the abstract of the paper.

Exaggerated by the ignorant tech press and the legacy media; misinterpreted by the public who probably did not read the article, let alone the paper it is based on.

Are we actively trying to become morons, or is it a passive process?

"Diversity of terrestrial microbiomes decreases with depth, while marine subsurface diversity and phylogenetic distance to cultured isolates rivals or exceeds that of surface environments."

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