User:Schiaparelliorbust/Alien Biosphere

This is a speculative evolution project currently maintained be me an MathAndCode.

Planet stats

Diameter: 1.06 Earth radii
Gravity: 1.2 G
Density: 1.12 Earth density Atmospheric density: 1.2 Earth air density
Atmospheric thickness: 1.2 Earth atmospheric thickness
Distance from suns: 1.2 AU
Stellar masses: 1 and 0.8 solar masses
Distance between stars: 0.17 AU
Stellar orbital eccentricity: 0.4
Day length: 20 hours

This list is incomplete.

Timeline

Thanks to MathAndCode for writing the timeline. This timeline is incomplete. I will try and expand it to include recent developments soon.
200 million years after the planet's formation: Life forms around hydrothermal vents and uses the reaction CO+H₂O→CO₂+H₂.
203 million years after the planet's formation: Life develops the reaction CO+H₂→H₂O+C.
204 million years after the planet's formation: Life develops the reaction CO₂+2H₂→2H₂O+C.
207 million years after the planet's formation: Some organisms around the hydrothermal vents start to use polysulfates as a mechanism of energy storage, recharging them using the reaction ROSO₃⁻+SO₃²⁻→ROSO₃SO₃⁻+2e⁻.
207 million years after the planet's formation: Organisms start to colonize the graphite fields, likely in order to avoid competition.
208 million years after the planet's formation: Some of the organisms near the hydrothermal vents adopt CH₃NO+HNCO→N₂+CO₂+CH₄ as a source of energy.
208 million years after the planet's formation: Organisms in the graphite fields evolve use the graphite as an energy source via 2H₂+C→CH₄. They use polycyclic aromatic hydrocarbons as reaction intermediates.
209 million years after the planet's formation: Polysulfate-building organisms develop an electron transport chain, which they use for the reaction SO₄²⁻+10H⁺+8e⁻→H₂S+4H₂O, using the energy to attach other free sulfate to sulfate chains.
209 million years ago: The reaction 2H₂+C→CH₄ is independently developed by some organisms near the hydrothermal vents.
209 million years after the planet's formation: Organisms performing CH₃NO+HNCO→N₂+CO₂+CH₄ start to colonize the area upcurrent of the hydrothermal vents.
209 million years after the planet's formation: Methane-making organisms in the graphite fields learn to use polycyclic aromatic hydrocarbons and derivatives to produce elemental hydrogen via the reaction H₂O+hv→H₂+½O₂. They haven't evolved oxygen resistance yet, so they quickly expel the oxygen, which will start to accumulate in the atmosphere, although not very quickly because photosynthetic organisms aren't widespread yet. Also, the organisms near the hydrothermal vents won't be affected much by the oxygen immediately because it is only being produced gradually so far, it readily reacts with other components of the atmosphere, and because there won't be much atmospheric gas dissolved in the water around the hydrothermal vents because they are deep underwater, and the high temperature and pressure will reduce water's ability to dissolve gases.
210 million years after the planet's formation: Organisms at the graphite fields evolve to immediately use the oxygen created to oxidize hydrocarbons as a mechanism of oxygen resistance. Some oxygen still escapes into the atmosphere, but the rate is reduced. Some oxygen reacts with the graphite, producing carbon monoxide and carbon dioxide. The carbon dioxide reacts with water to produce carbonic acid, which causes localized acidification of the ocean.
211 million years after the planet's formation: Polysulfate-building organisms take advantage of the increasing amount of methane by getting energy from the net reaction H₂SO₄+CH₄→CO₂+2H₂O+H₂S.
211 million years after the planet's formation: Graphite field colonists evolve to harness the energy released by the reactions that they use to destroy the oxygen that they create.
211 million years after the planet's formation: Some of the organsims in the shallowest part of the graphite field evolve to synthesize ammonia, both for energy and in order to cancel out the acidity of carbonic acid.
212 million years after the planet's formation: Graphite field colonists start to use photosynthesis to synthesize carbohydrates directly using water and carbon monoxide.