Sagan 4 Forum [Menu]

It wasn't graveyarded, suggesting it wasn't rejected or discarded. I believe this is salvageable with minimal changes, though the easiest way to salvage it would reduce its scale to a single-species submission. Of course, entirely replacing Tetrabrachs Lamarck beaches would be implausible, especially if it's just one species, but that part can simply be omitted.

The problem is that an entirely novel light-capturing pigmented would have to be invented from scratch to allow it to perform photosynthesis. Its primary adaptation is implausible.

Could it have two versions of its gene for its primary pigment and have one mutated and so be a different, more bluish shade of purple, and this pigment is only expressed in young tissue? Can it be a non-photosynthetic pigment, like delphinidin? Is using anthocyanin instead not an option? Can it simply be recolored to be much closer to its ancestor's shade and have a structural color effect on its leaves?

Could use this one perhaps....

https://en.wikipedia.org/wiki/Coelenterazine

In the process, coelenterazine is oxidized with a concurrent loss of CO2, and a photon of blue light is emitted.

QUOTE (Coolsteph @ May 20 2023, 01:31 PM)

Could it have two versions of its gene for its primary pigment and have one mutated and so be a different, more bluish shade of purple, and this pigment is only expressed in young tissue? Can it be a non-photosynthetic pigment, like delphinidin? Is using anthocyanin instead not an option? Can it simply be recolored to be much closer to its ancestor's shade and have a structural color effect on its leaves?

Any non-photosynthetic pigment affects its ability to photosynthesize. Anthocyanin blocks its ability to perform photosynthesis.

Structural colors (i.e., an illusion which does not use pigments), shouldn't interfere. Wax deposits, such as those on blue spruce or chalk dudleyas, should allow for a bluer appearance than would ordinarily be expected. Certain species of ferns (e.g., Selaginella) can grow bluish-seeming iridescent leaves in low-light conditions, which would allow for a Tetrabrach descendant to plausibly have bluer-looking leaves without interfering with photosynthesis.

However, since these developed under low-light conditions, for this explanation to make sense, the habitat would have to be changed to a lower-light habitat, and these would either have to be made much shorter, or the iridescent indigo leaves would have to be modified to only appear in individuals growing in shaded conditions (possibly only temporarily, being rapidly shed when an opening in the canopy shows up). Admittedly, the very shape of the Violet Neopalm isn't very fern-like, so this workaround necessitates a new image to make it seem plausible as a fern-like shade-dweller.

Source:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2850791/

QUOTE (Primalpikachu @ Apr 30 2023, 04:37 PM)

QUOTE (Disgustedorite @ Apr 30 2023, 06:44 PM) QUOTE (Primalpikachu @ Apr 30 2023, 05:36 PM) QUOTE (Disgustedorite @ Apr 29 2023, 11:42 AM) How is it able to use phycocyanin with retinol? Phycocyanin passes light to the main pigment, but if they can't exist in the same place, this does not occur. My idea was that the Phycocyanin, being attached to the membrane in clusters, would, in a way, checkerboard the light structures, with clusters of phycocyanin outside the membrane and areas within the membrane dedicated to retinol. That is not how accessory pigments work. That just makes it only get half as much light and zero energy from the phycocyanin. Phycocyanin does not perform photosynthesis on its own. It converts additional wavelengths into the blue light that chlorophyll can use. When paired with retinol, it creates light that the retinol can't actually use, because it uses the inverse colors from chlorophyll. It also makes no sense for it to replace its ancestor even if it does have a working accessory pigment, because changing photosynthesis color is changing niche. Ah, I see; hmm, in that case, I'm not sure what to do here; it may be best to scrap this idea.

Do you wish to scrap the idea?

I think removing it displacing other flora, making it strictly full sun, and giving it pigment unrelated to photosynthesis and ranging in concentrations dependent on light levels could allow this to exist.

This would mean that if shaded it would revert to a more purple form, as red plants on earth revert to green in shade as need for light overrides other colors.