Jayngfet wrote:The differences kind of also just raise further questions. After all Mitochondria generate necessary energy in almost all multicellular life, especially the complex life forms you can see with your naked eye. So you have to ask where is all that energy coming from in organisms that lack it.
Mitochondria synthesize ATP, which is what our cells use for energy, but they have another unusual quality: they're not just regular cellular organelles like the nucleus or ribosomes or chloroplasts... they're essentially symbiotic organisms with their own DNA. It's true that almost all multicellular life on Earth have mitochondria, but that's surely because almost all multicellular life evolved from the same common ancestor. I don't think there's anything fundamental to ATP production that requires this strange genetic configuration, and I assume that this is merely a quirk of our early evolution. Alien organisms, even when they run on chemistry very similar to ours, might have organelles which produce ATP, but I doubt they would be Earth-style mitochrondria with separate DNA from the rest of the cell, so I'm not sure we can really call them "mitochondria." (Nomenclature for exobiologists will be really strange and frustrating.)
I think that nearly all complex alien life will be built out of cells, and many will specialize their cells in similar ways to Earth organisms (muscle cells, skin cell, nerve cells, etc.), but I think it's fantastically unlikely that those cells will have internal processes and structures that are identical to those of Earth organisms, even if they operate on essentially the same chemical processes. The marvelous and very specific way our cells function is surely at least in part a unique quirk of the history and environment of early Earth evolution, and alien life almost certainly will have different (if similar) fingerprints.
But even if your cellular building blocks have differing internal structures, this may not have much of an impact on the larger-scale structures they form. You can build essentially the same Lego structures out of Tente or Meccano blocks (especially at a large scale), even if the building blocks are structured differently and are mutually incompatible.
My assumption is that all Soia-Liron organisms share the same genetic code base and consequently all have cells that are essentially the same (as the cells of most complex Earth organisms are). A Loroi can have very similar tissue and organ structure to a human, even if her cells are structured differently. Why would someone bother creating such dopplegangers, rather than just using the native organisms themselves? There are a number of reasons, but the one I'll mention is that Loroi and Barsam have some very specific advantages over their human and Nibiren counterparts, which we've talked about before.