[Written with the help of GPT-4]
“Panspermia” is the hypothesis that organic life originated elsewhere in the universe and was brought to Earth either accidentally by a meteor or deliberately by intelligent aliens. While it might be true, there’s no evidence to support it, and it’s most likely life originated here. Once our spacefaring and genetic engineering technology improves, we will be able to make panspermia a reality by seeding other celestial bodies with life forms designed to thrive there.
Why do that? It could let us “terraform” other planets and moons–a process of gradual transformation of an environment to match Earthly conditions. For example, if we found a planet whose atmosphere contained too little oxygen and too much carbon dioxide for humans to breathe, we could introduce plants and bacteria that consumed carbon dioxide and excreted oxygen as part of their metabolisms. The atmosphere’s composition would eventually shift as intended.
Will we ever terraform another planet or moon? No…WE…won’t since we humans won’t be in charge of the space program by the time the option to do this becomes available. However, the AGIs and/or posthumans who will be in charge might.
Being rational agents, they won’t seed other planets and moons with life just for its own sake, as some starry-eyed sci-fi novelists think we should do. They will only do so if it serves a higher purpose that benefits them. (Additionally, I hope that advanced ethics go hand-in-hand with advanced intelligence, and they think twice about manufacturing ecosystems where none existed before just so countless animals will arise only to suffer and die, without any ultimate purpose.)
What purpose could organic life in other star systems serve? Biological intelligences could serve as “backups” for their AGI masters. Machines are vulnerable to hazards that biological organisms are not, like computer viruses and electromagnetic pulses. Keeping biological intelligences around would increase the “slack” and resiliency of civilization since they could help or rebuild the machines if something laid the latter low.
Notice I used “biological intelligences” and not “humans” in the last paragraph. Even if AGIs found the need for such a niche, it’s unlikely they’d use humans to fill it. For one, we’re not properly evolved to live on other planets. Even a small difference in gravity would wreak havoc on our health. Second, humans are not the pinnacle of complex organic life. There are ways to make life forms that are smarter, stronger, faster, more obedient, and more efficient than we are. Given the chance to engineer servants from genetic scratch, doubtless AGIs will make creations with no link to Homo sapiens. Third, humans will probably be more trouble than we’re worth given our sense of lost greatness and resentment towards the AGIs that surpassed us. Why would AGIs want to spread that attitude across the cosmos when they could instead make wholly new intelligent species that have no historical or cultural baggage and only express gratitude for being brought into existence?
Intelligent life forms are only useful as backups if they can survive without AGI help and can survive at least some of the disasters that could wipe out AGIs. If all of the faithful humanoids are living on a space station, the same EMP that disables all the AGIs will also destroy the electronic systems in the station, ultimately killing the humanoids. Therefore, in every star system where there is an AGI presence, there must be a planet or moon where the humanoids live in the midst of a self-sustaining, closed ecosystem. This requirement necessitates terraforming.
Imagine a colony in a distant star system, 10,000 years from now. The most important aspect of the colony would be a Dyson Swarm that enshrouded most of the star, harvesting nearly all of its energy. Each component of the Swarm would be a large satellite. A tiny hole would be kept open in the Swarm so light could strike the surface of a planet, roughly the size of Earth. The planet would teem with millions of species of organic life forms, engineered to thrive in the planet’s conditions and to function together. Any resemblances to Earthly life would be coincidental and the result of designing life forms to function best under similar external constraints.
The ecosystem would exist solely to keep the planet naturally habitable for a species of biological intelligences. Depending on what is found to thrive best on that specific planet, they may or may not be humanoid or may be bigger or smaller than humans. For sure, they will be at least as good as we are at understanding technology, and they will be more loyal and obedient to authority than we are.
To these life forms, the understanding that they were created by machines to serve machines will come naturally and be accepted without resentment. They will be more acquainted with how to survive catastrophes and will know the function if one day the lights go out and big chunks of the Swarm start falling out of the sky.
Will every star system have a planet (or moon) full of organic backups? Probably not, since there are many systems amenable to Dyson Swarm construction while also being hostile to organic life. For example, there are star systems that lack rocky planets, or that have rocky planets that are not the right distance from their stars. Given the limitations of organic chemistry, no kind of complex, intelligent animal could live on a hot planet like Mercury without constant technological support.
If panspermia ever becomes reality, it may not be the work of dreamers scattering Earth’s seeds across the stars, but of machines ensuring their own continuity. Organic life, then, will not be humanity’s legacy but civilization’s survival mechanism.