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Man-made evolution?


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This kind of relates to a discussion I started once about the terraforming of other planets.

 

I don't remember if we covered this part.

 

Here's the scenario I was wondering about;

 

-Something came crashing into Venus.

-Said object was big, heavy and fast enough to knock away the harsher parts of the atmosphere.

-The planet is now on a different axis that causes it to rotate the same way as Earth.

-Before the whole incident there were already primitive microorganisms on the surface.

 

Under the new, Earth-like conditions that have befallen Venus in this scenario, what would happen to said microbes? Would they start to evolve, or would they stay unchanged?

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They already evolved to become the microbes they were. What's there to stop the surviving ones to continue that trend?

 

Changing conditions is what killed the dinosaurs, isn't it? When the meteor hit most life on Earth was destroyed, excluding those who hid well enough from what was thrown into the atmosphere.

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Under the new, Earth-like conditions that have befallen Venus in this scenario, what would happen to said microbes? Would they start to evolve, or would they stay unchanged?

 

The microbes were evolving before and will continue to evolve in the new environment.

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why do you think they would remain unchanged? assuming there are reproducing survivors with all the new selective pressures they're exposed to they will probably evolve.


 

Changing conditions is what killed the dinosaurs, isn't it? When the meteor hit most life on Earth was destroyed, excluding those who hid well enough from what was thrown into the atmosphere.

but the surviving organisms continued to change. if they didn't why would we be here?

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In a fictional setting the chances are exactly as the author wants them to be.

I think this is right, you have set up this amazing scenario, just tell us a few of the original organisms survive in some pocket of gas similar to the original conditions, then you have the chance to survive and gradually evolve. But if the change was from 400 degrees straight down to 25 degrees it is likely nothing would survive such a dramatic change. The rotation of the planet would have little effect but the heating of an impact could sterilize the surface.

Edited by Robittybob1
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Venus has probably been a 'wasteland' since shortly after it formed.

It's not like it was ever earthlike, and runaway greenhouse effects altered it, to the way it is today.

 

Oh, and dinosaurs did not all become extinct. Some did survive and continued to evolve in the new environment.

You may have had one for supper. You do like chicken don't you ?

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That would be a wild guess wouldn't it?

No. What makes you think it is a wild guess? A simple literature search would have revealed the wild guess was yours. For example:

 

Driscoll, P. and Bercovici, D. "Divergent evolution of Earth and Venus: Influence of degassing, tectonics, and magnetic fields." Volume 226, Issue 2, November–December 2013, Pages 1447–1464

 

Abstract

Knowledge of the earliest evolution of Earth and Venus is extremely limited, but it is obvious from their dramatic contrasts today that at some point in their evolution conditions on the two planets diverged. In this paper we develop a geophysical systems box model that simulates the flux of carbon through the mantle, atmosphere, ocean, and seafloor, and the degassing of water from the mantle. Volatile fluxes, including loss to space, are functions of local volatile concentration, degassing efficiency, tectonic plate speed, and magnetic field intensity. Numerical results are presented that demonstrate the equilibration to a steady state carbon cycle, where carbon and water are distributed among mantle, atmosphere, ocean, and crustal reservoirs, similar to present-day Earth. These stable models reach steady state after several hundred million years by maintaining a negative feedback between atmospheric temperature, carbon dioxide weathering, and surface tectonics. At the orbit of Venus, an otherwise similar model evolves to a runaway greenhouse with all volatiles in the atmosphere. The influence of magnetic field intensity on atmospheric escape is demonstrated in Venus models where either a strong magnetic field helps the atmosphere to retain about 60 bars of water vapor after 4.5 Gyr, or the lack of a magnetic field allows for the loss of all atmospheric water to space in about 1 Gyr. The relative influences of plate speed and degassing rate on the weathering rate and greenhouse stability are demonstrated, and a stable to runaway regime diagram is presented. In conclusion, we propose that a stable climate-tectonic-carbon cycle is part of a larger coupled geophysical system where a moderate surface climate provides a stabilizing feedback for maintaining surface tectonics, the thermal cooling of the deep interior, magnetic field generation, and the shielding of the atmosphere over billion year time scales.

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No. What makes you think it is a wild guess? A simple literature search would have revealed the wild guess was yours. For example:

 

Driscoll, P. and Bercovici, D. "Divergent evolution of Earth and Venus: Influence of degassing, tectonics, and magnetic fields." Volume 226, Issue 2, November–December 2013, Pages 1447–1464

 

Abstract

Knowledge of the earliest evolution of Earth and Venus is extremely limited, but it is obvious from their dramatic contrasts today that at some point in their evolution conditions on the two planets diverged. In this paper we develop a geophysical systems box model that simulates the flux of carbon through the mantle, atmosphere, ocean, and seafloor, and the degassing of water from the mantle. Volatile fluxes, including loss to space, are functions of local volatile concentration, degassing efficiency, tectonic plate speed, and magnetic field intensity. Numerical results are presented that demonstrate the equilibration to a steady state carbon cycle, where carbon and water are distributed among mantle, atmosphere, ocean, and crustal reservoirs, similar to present-day Earth. These stable models reach steady state after several hundred million years by maintaining a negative feedback between atmospheric temperature, carbon dioxide weathering, and surface tectonics. At the orbit of Venus, an otherwise similar model evolves to a runaway greenhouse with all volatiles in the atmosphere. The influence of magnetic field intensity on atmospheric escape is demonstrated in Venus models where either a strong magnetic field helps the atmosphere to retain about 60 bars of water vapor after 4.5 Gyr, or the lack of a magnetic field allows for the loss of all atmospheric water to space in about 1 Gyr. The relative influences of plate speed and degassing rate on the weathering rate and greenhouse stability are demonstrated, and a stable to runaway regime diagram is presented. In conclusion, we propose that a stable climate-tectonic-carbon cycle is part of a larger coupled geophysical system where a moderate surface climate provides a stabilizing feedback for maintaining surface tectonics, the thermal cooling of the deep interior, magnetic field generation, and the shielding of the atmosphere over billion year time scales.

But did MigL know about this? A wild guess could sometimes be right. That article is way beyond me at this stage. But thanks for enlightening me.

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But did MigL know about this?

I shall make a wild guess: he has an education and takes the time and trouble to study things that interest him.

 

 

@the OP: I am unaware of any mechanism, or combination of mechanisms that could permit organic life to remain intact at the temperatures present at the surface of Venus. Therefore your opening premise is not realisable in practice.

 

If you do wish "to know how it could work in real life with real sciences applied" then you need to specify the character of the microbes that we wish to imagine living there. Different characters will mean different responses to the changed environment. That's why, from the same starting point, some of us became humans and others became gladioli.

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Venus has probably been a 'wasteland' since shortly after it formed.

It's not like it was ever earthlike, and runaway greenhouse effects altered it, to the way it is today.

 

Oh, and dinosaurs did not all become extinct. Some did survive and continued to evolve in the new environment.

You may have had one for supper. You do like chicken don't you ?

 

I already knew about the link between birds and the raptor family of dinosaurs.

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