How Extensive Is Life Deep Beneath Earth's Surface?

[jim mcnamara]

https://phys.org/news/2018-12-life-deep-earth-totals-billion.html
This report from DCO is a kind of review article. This article itself does not have specific reference papers cited. Just another review article. I think the DCO people expect us to dig around a little. Plus there are ~300 DCO scientists active in the group.

Per the article: there is a LOT of subsurface carbon - read living organisms - the estimates are large:
continental subsurface hosts are 2 to 6 × 10^29 cells.

Many of the species found come from solid rock with some stress fractures (because a lot the samples come from seismically active sites or from kilometers beneath the seabed.)

One interesting point is that many subsurface organisms spend little energy on growth, they simply exist. Evolution is in "standby":
https://phys.org/news/2017-03-microorganisms-subsurface-seabed-evolutionary-standby.html

 

[jedishrfu]

This bring back memories of Verne and the Journey to the Center of the Earth

https://en.m.wikipedia.org/wiki/Journey_to_the_Center_of_the_Earth

 

[Auto-Didact]

Just saw this elsewhere. I heard the amount of subsurface life takes up about 2.5 times the volume of all the oceans on Earth! That is absolutely insane!

Estimates say it totals about 70% of all biomass on Earth. This hitherto hidden 'dark bio-matter' means that biologists, just like physicists, have only barely scraped the surface of their subject.

It is very exciting to learn about the evolutionary path of this subterranean life: who got here first? Us, surface dwellers, or them?

 

[jim mcnamara]

This link discusses your concept. https://phys.org/news/2017-03-microorganisms-subsurface-seabed-evolutionary-standby.html
It is more like every extant clade started out in a common medium, then some went further "South", while others stayed above the rock stata. There are ascarid worms down in the rock fractures for example. There are lots of ascarid worms up on land.
Examples:
Human parasites - https://www.cdc.gov/parasites/ascariasis/index.html
800 million - 1.2 billion humans are infected. The CDC article in the link is meant for non-Biologists. It should be fun read, that induces nightmares.

 

[Auto-Didact]

Human parasites - https://www.cdc.gov/parasites/ascariasis/index.html
800 million - 1.2 billion humans are infected. The CDC article in the link is meant for non-Biologists. It should be fun read, that induces nightmares.

I saw a few of those back in med school. Nothing a bit of mebendazole shouldn't be able to take care of :)

 

[mfb]

Just saw this elsewhere. I heard the amount of subsurface life takes up about 2.5 times the volume of all the oceans on Earth! That is absolutely insane!

No, that is the volume where life exists. It corresponds to an average depth of 6 km. Life is a tiny fraction of that volume. 7.5 tonnes of carbon per cubic kilometer are maybe 75 tonnes of biomass per 2 billion tonnes, or ~40 parts in a billion.