07-03-2015, 06:24 PM
One thing that figures in the Reconstruction series is the idea of "tetralife." Mainly as a plot device to deprive the descendant cultures access to Earth. As the story goes in that setting, after life as we knew it got wiped out on Earth in The Kerpockeyclypse, tetralife arose in its place. Tetralife had been a theoretical study for a few decades at that point, and genomes for many tetralife species had been grown in simulation and worked out theoretically in research journals (which journals are known to the religious among the survivors as "The Books Of Abominations"). A limited set of these otherwise-theoretical species, mostly tetrafungi, had apparently been produced in actual molecules rather than just in simulation, and spores for "Shaitan's Toadstools" were evidently on the surface and viable after the Kerpockeyclypse.
Nobody's quite sure whether they were originally a contained biology experiment that was protected in some lab when the surface got irradiated, or whether they were deliberately deployed as weapons in the Kerpockeyclypse, but by the time of the stories, it really doesn't matter, because none of the polities responsible for the Kerpockeyclypse survived it.. Many different earth-descended groups have religious interpretations of tetralife's significance (as well as disagreements about the eschatological significance of the actual now-historical apocalypse and end of the world) though. Anyway, tetralife is "just" standard DNA-based life with a different set of ribosomes, so it codes for proteins in quartet groups rather than in triplet groups.
This gives tetralife a 4x larger 'vocabulary' of proteins that it can code for, and makes it possible for tetralife to be constructed with many proteins that are not used in trilife forms such as ourselves. Unfortunately, that means that while tetralife contains proteins that trilife cannot digest nor target with our immune defenses, the converse is not true. And therefore, now that the surface of Earth is more or less home to an ecology of tetraslimes, tetramolds, and tetrafungi, it means that unless we absolutely and completely sterilize it first, (which is damned hard because tetrafungus spores are at least an order of magnitude tougher than trilife fungus spores) just one breath of the air is reliably fatal for any trilife organism.
This left the remnant populations hanging on in the asteroid belts and space station habs in a really bad situation because they had all been relying on earth for resupply, repair parts, and infrastructure. So there was the mad scramble for survival, where about 80% of the offworld populations died off, and then the long hard slog of the reconstruction period where the stories are set, and aside from a couple of research stations that invest more in physical protection and fully-contained life support than the Mercury stations, nobody can live on Earth.
Anyway - a "moderately plausible" scenario about how Earth could go on to have a thriving, vibrant, diverse (well, diverse types of slimes, molds and fungi anyway) ecology with absolutely no space for us anywhere in it.
Nobody's quite sure whether they were originally a contained biology experiment that was protected in some lab when the surface got irradiated, or whether they were deliberately deployed as weapons in the Kerpockeyclypse, but by the time of the stories, it really doesn't matter, because none of the polities responsible for the Kerpockeyclypse survived it.. Many different earth-descended groups have religious interpretations of tetralife's significance (as well as disagreements about the eschatological significance of the actual now-historical apocalypse and end of the world) though. Anyway, tetralife is "just" standard DNA-based life with a different set of ribosomes, so it codes for proteins in quartet groups rather than in triplet groups.
This gives tetralife a 4x larger 'vocabulary' of proteins that it can code for, and makes it possible for tetralife to be constructed with many proteins that are not used in trilife forms such as ourselves. Unfortunately, that means that while tetralife contains proteins that trilife cannot digest nor target with our immune defenses, the converse is not true. And therefore, now that the surface of Earth is more or less home to an ecology of tetraslimes, tetramolds, and tetrafungi, it means that unless we absolutely and completely sterilize it first, (which is damned hard because tetrafungus spores are at least an order of magnitude tougher than trilife fungus spores) just one breath of the air is reliably fatal for any trilife organism.
This left the remnant populations hanging on in the asteroid belts and space station habs in a really bad situation because they had all been relying on earth for resupply, repair parts, and infrastructure. So there was the mad scramble for survival, where about 80% of the offworld populations died off, and then the long hard slog of the reconstruction period where the stories are set, and aside from a couple of research stations that invest more in physical protection and fully-contained life support than the Mercury stations, nobody can live on Earth.
Anyway - a "moderately plausible" scenario about how Earth could go on to have a thriving, vibrant, diverse (well, diverse types of slimes, molds and fungi anyway) ecology with absolutely no space for us anywhere in it.