Let's create an alien biosphere!

[Schiaparelliorbust]

I think that the video that you sent me said that plants don't use green light because their ancestors evolved in a world where the green light was already taken up by organisms closer to the surface. The early life here would probably have a variety of colors.

Was it this video? I've sent you several. If yes, it's been a while since I watched it. Also, I found all of these photosynthetic pigments on Wikipedia:
Carotene: an orange pigment
Xanthophyll: a yellow pigment
Phaeophytin a: a gray-brown pigment
Phaeophytin b: a yellow-brown pigment
Chlorophyll a: a blue-green pigment
Chlorophyll b: a yellow-green pigment

[MathAndCode]

Was it this video?

Yes, that's it.

Also, I found all of these photosynthetic pigments on Wikipedia:

Keep in mind that the absorption spectra for each can be shifted somewhat by changing the functional groups.

[Schiaparelliorbust]

Keep in mind that the absorption spectra for each can be shifted somewhat by changing the functional groups.

So you can just ''adjust'' them? Do you think we should get our molecules like that?

[MathAndCode]

So you can just ''adjust'' them? Do you think we should get our molecules like that?

Yes, that seems more likely to evolve than a completely new photosynthetic molecule.

[Schiaparelliorbust]

Yes, that seems more likely to evolve than a completely new photosynthetic molecule.retinal

Can you please do the tweaking? I don't know how to do it. Do you think purple is good? AFAIR from the video, the purple bacteria used retinal and it seems to have a relatively simple structure.

[MathAndCode]

Can you please do the tweaking? I don't know how to do it.

I don't think that we have to specify the exact changes.

Do you think purple is good? AFAIR from the video, the purple bacteria used retinal and it seems to have a relatively simple structure.

It's more about the structure and less about the color. Retinal is related to carotenes, which are orange.

[Schiaparelliorbust]

I don't think that we have to specify the exact changes.

Good.

It's more about the structure and less about the color. Retinal is related to carotenes, which are orange.

Oh, ok. If we changed them would they still likely be orange?

[MathAndCode]

Oh, ok. If we changed them would they still likely be orange?

No, their absorption frequencies would likely shift.

[Schiaparelliorbust]

No, their absorption frequencies would likely shift.

Would they shift arbitrarily? I mean purple (retinal) is very far away from orange (carotenes).

[MathAndCode]

Would they shift arbitrarily? I mean purple (retinal) is very far away from orange (carotenes).

I think that there are some rules concerning which direction, but I don't think that it's necessary to worry about the specifics.

[Schiaparelliorbust]

I think that there are some rules concerning which direction, but I don't think that it's necessary to worry about the specifics.

Then do you have any preference for the color?

[MathAndCode]

Then do you have any preference for the color?

I think that organisms will likely use multiple colors in order to be able to get more energy.

[Schiaparelliorbust]

I think that organisms will likely use multiple colors in order to be able to get more energy.

Then let's choose a few colors. I think there should be red and green at least.

[MathAndCode]

Then let's choose a few colors. I think there should be red and green at least.

There will probably also be something between orange and yellow and something between blue and violet.
Also, be aware that some compounds may have multiple absorption peaks. Chlorophyll is one example.

[Schiaparelliorbust]

There will probably also be something between orange and yellow and something between blue and violet.
Also, be aware that some compounds may have multiple absorption peaks. Chlorophyll is one example.

Yes. Then can we have perhaps four pigments? They could be red, orange-yellow, green, and blue-violet. A single organism can use two different pigments, like red algae, which uses both chlorophyll and phycoerythrin, which is red.

[MathAndCode]

Yes. Then can we have perhaps four pigments? They could be red, orange-yellow, green, and blue-violet. A single organism can use two different pigments, like red algae, which uses both chlorophyll and phycoerythrin, which is red.

Yes, and through methods before, it could probably adjust the frequencies somewhat through various modifications.

[Schiaparelliorbust]

Yes, and through methods before, it could probably adjust the frequencies somewhat through various modifications.

Because our planet is in the Lagrange point, the third of the planet facing the suns will get more sunlight. We could have photosynthesizers with pigments more tolerant to radiation there, and less tolerant ones in the two sixths around receiving less sunlight.

[MathAndCode]

Because our planet is in the Lagrange point, the third of the planet facing the suns will get more sunlight. We could have photosynthesizers with pigments more tolerant to radiation there, and less tolerant ones in the two sixths around receiving less sunlight.

I thought that we agreed to go back to a P-type system. Also, the planet definitely shouldn't be tidally locked.

[Schiaparelliorbust]

I thought that we agreed to go back to a P-type system. Also, the planet definitely shouldn't be tidally locked.

Oh ok sorry. How far is the planet now? Also, the stuff I said still applies to latitude differences.

[MathAndCode]

Oh ok sorry. How far is the planet now? Also, the stuff I said still applies to latitude differences.

The habitable zone is still at the same distance. Should I type it again?

[Schiaparelliorbust]

The habitable zone is still at the same distance. Should I type it again?

Yes please. I think at most one or two groups of photosynthesizers should be the dominant group too.

[MathAndCode]

Yes please.

The distance is 1.2 AU.

I think at most one or two groups of photosynthesizers should be the dominant group too.

That's the most likely situation. However, the other groups will likely continue to persist.

[Schiaparelliorbust]

That's the most likely situation. However, the other groups will likely continue to persist.

Yes, I was never advocating the eradication of the other groups. So now that we have photosynthesizers, let's determine which groups become dominant and create single or pluricellular (not multicellular, more like an algae mat) groups that eat them.

[MathAndCode]

Yes, I was never advocating the eradication of the other groups. So now that we have photosynthesizers, let's determine which groups become dominant and create single or pluricellular (not multicellular, more like an algae mat) groups that eat them.

Actually, we should decide the reactions first, as the planet could undergo an analog of the Oxygen Catastrophe that could change the hierarchy.

[Schiaparelliorbust]

Actually, we should decide the reactions first, as the planet could undergo an analog of the Oxygen Catastrophe that could change the hierarchy.

Do you mean the photosynthetic reactions?