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I wonder if there's any depth we've searched where we haven't found life. It looks like life is everywhere we look. Is there anywhere on Earth there isn't some

I wonder if there's any depth we've searched where we haven't found life. It looks like life is everywhere we look. Is there anywhere on Earth there isn't some microbe living?

nuccy 6y ago
Just to put a bit of a context here, life exists on Earth for 4 billion years (single celled), and 1.5 billion years (multicellular) [1]. There were few mass extinction events in the history of Earth, at least 5 happened in the last 540 million years with up to 50% of life disappearing [2]. There were before periods with much more diverse life, than what we have now, so probably life before occupied the whole planet [3], obviously not all of that species left themselves in fossils, so exact numbers are a matter of big debates. [1] https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h... [2] https://en.wikipedia.org/wiki/Extinction_event https://en.wikipedia.org/wiki/Extinction_event [3] https://en.wikipedia.org/wiki/Cambrian_explosion https://en.wikipedia.org/wiki/Cambrian_explosion
- close04 6y ago
  > 50% of life Worse, 50% of species. And the P-T extinction was the worst with an estimated 96% of all marine species and 70% of terrestrial vertebrates becoming extinct.
Someone 6y ago
Reading https://www.nationalgeographic.com/news/2017/04/deepest-life-earth-mariana-trench-astrobiology-science/ https://www.nationalgeographic.com/news/2017/04/deepest-life..., scientists think temperatures above 250F (120 °C) aren’t compatible with life as we know it (carbon-based, using water), and, because of that, there isn’t life below 6 miles down. Reading https://en.wikipedia.org/wiki/Methanopyrus https://en.wikipedia.org/wiki/Methanopyrus, about a microbe that “can survive and reproduce at 122 °C”, that limit may be based on observation, rather than first principles. Regardless, I would take it with a grain of salt.
- close04 6y ago
  Some archaea species like Geogemma barosii [0] can survive and reproduce at temperatures above 121 °C (the temperature used in many autoclaves for example). [0] https://en.wikipedia.org/wiki/Strain_121 https://en.wikipedia.org/wiki/Strain_121
  - dumbfoundded 6y ago
    That's pretty awesome that the only limitations of life on Earth appear to be pressure and temperature.
hosteur 6y ago
In the center?
- dumbfoundded 6y ago
  It's kind of hard to look there.
ornxka 6y ago
Life is virtually everywhere, appreciable levels of biodiversity are not. Things get smaller, slower, simpler, and fewer as you start to move towards the fringe.
- dumbfoundded 6y ago
  I'm not sure how biodiversity is measured for single celled organisms. I always thought the genetic variation was higher for the domain Archaea whereas the genetic variation was smaller for other domains but led to much more different emergent properties.
zxcvbn4038 6y ago
Let’s hope the life on Mars was just as robust.

I wonder if there's any depth we've searched where we haven't found life. It looks like life is everywhere we look. Is there anywhere on Earth there isn't some microbe living?

nuccy 6y ago

Just to put a bit of a context here, life exists on Earth for 4 billion years (single celled), and 1.5 billion years (multicellular) [1]. There were few mass extinction events in the history of Earth, at least 5 happened in the last 540 million years with up to 50% of life disappearing [2]. There were before periods with much more diverse life, than what we have now, so probably life before occupied the whole planet [3], obviously not all of that species left themselves in fossils, so exact numbers are a matter of big debates. [1] https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h... [2] https://en.wikipedia.org/wiki/Extinction_event https://en.wikipedia.org/wiki/Extinction_event [3] https://en.wikipedia.org/wiki/Cambrian_explosion https://en.wikipedia.org/wiki/Cambrian_explosion

close04 6y ago
> 50% of life Worse, 50% of species. And the P-T extinction was the worst with an estimated 96% of all marine species and 70% of terrestrial vertebrates becoming extinct.

Someone 6y ago

Reading https://www.nationalgeographic.com/news/2017/04/deepest-life-earth-mariana-trench-astrobiology-science/ https://www.nationalgeographic.com/news/2017/04/deepest-life..., scientists think temperatures above 250F (120 °C) aren’t compatible with life as we know it (carbon-based, using water), and, because of that, there isn’t life below 6 miles down. Reading https://en.wikipedia.org/wiki/Methanopyrus https://en.wikipedia.org/wiki/Methanopyrus, about a microbe that “can survive and reproduce at 122 °C”, that limit may be based on observation, rather than first principles. Regardless, I would take it with a grain of salt.

close04 6y ago
Some archaea species like Geogemma barosii [0] can survive and reproduce at temperatures above 121 °C (the temperature used in many autoclaves for example). [0] https://en.wikipedia.org/wiki/Strain_121 https://en.wikipedia.org/wiki/Strain_121
- dumbfoundded 6y ago
  That's pretty awesome that the only limitations of life on Earth appear to be pressure and temperature.

hosteur 6y ago

In the center?

dumbfoundded 6y ago
It's kind of hard to look there.

ornxka 6y ago

Life is virtually everywhere, appreciable levels of biodiversity are not. Things get smaller, slower, simpler, and fewer as you start to move towards the fringe.

dumbfoundded 6y ago
I'm not sure how biodiversity is measured for single celled organisms. I always thought the genetic variation was higher for the domain Archaea whereas the genetic variation was smaller for other domains but led to much more different emergent properties.

zxcvbn4038 6y ago

Let’s hope the life on Mars was just as robust.