_tom_ 15 hours ago

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),

BurningFrog 17 hours ago

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

drjasonharrison 17 hours ago

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?

  • scientator 16 hours ago

    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.

  • r00fus 16 hours ago

    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.

fritzo 18 hours ago

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

  • marinmania 17 hours ago

    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.

  • ljlolel 18 hours ago

    Would be more about total energy

    • ceejayoz 17 hours ago

      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.

      • jvanderbot 17 hours ago

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

        • dathinab 17 hours ago

          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.

pseudony 16 hours ago

Gears of war, anyone ?

ziknard 16 hours ago

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?

  • Oarch 16 hours ago

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