An overdue thanks for the numerous responses to my biology questions*. I am continuing to investigate the question of the origin of eukaryote tissues. I feel like a doof for not recalling the obvious fact that there are photosynthetic pigments other than chlorophyll. My question should properly have been why green was the most successful colour.
My remarks on the shape of the cosmos have garnered even more comments, leaving me with a fresh question: can the cosmos be described as a three-dimensional manifold embedded in four-space?** Isn't it good we have me around to worry about this sort of thing? I would much rather be pondering this than the source of my next meal, etc.
___
* I heard that, you perverts.
** Like the chlorophyll, I ought to know the answer to this, but have forgotten it. I have the vague impression we're living on the three-dimensional surface of a hypersphere.