I would expect most life to just end up as planets full of green goo (ie. like grey goo but natural).
One might compare this to ecosystems of reproducing known-number iterated prisoner’s dilemma robots—the analogous idea is that these ecosystems will usually end up as “tit for tat goo.”
Tit for tat is reliable. Like algae in the sea of early earth, tit for tat can serve as a “background” for our ecosystem—cooperation is harvesting energy from the sun, defection is being a predator, but if everyone tries to be a predator everyone dies. So algae reproduces. But also like a sea full of algae, there are predatory / parasitic strategies that work really well once the plants are common, like defecting at the end, or eating plants. If a tit for tat robot has the first mutant baby that defects at the end, that baby will only play against tit for tat robots, so it will defect successfully and have more babies than usual, eventually leading to a whole new strain. The zooplankton of the ecosystem. But then if that becomes common, it may be worth it to produce a parasite to the parasite—defecting twice from the end. The bigger the possible rewards, the more layers of strategies will be viable. Tit for tat goo is unstable—plants quickly grow herbivores, and herbivores can sometimes grow predators.
And that’s just iterated prisoner’s dilemma. Add in more dimensions, multiple equilibria… things could get pretty complicated.
One might compare this to ecosystems of reproducing known-number iterated prisoner’s dilemma robots—the analogous idea is that these ecosystems will usually end up as “tit for tat goo.”
Tit for tat is reliable. Like algae in the sea of early earth, tit for tat can serve as a “background” for our ecosystem—cooperation is harvesting energy from the sun, defection is being a predator, but if everyone tries to be a predator everyone dies. So algae reproduces. But also like a sea full of algae, there are predatory / parasitic strategies that work really well once the plants are common, like defecting at the end, or eating plants. If a tit for tat robot has the first mutant baby that defects at the end, that baby will only play against tit for tat robots, so it will defect successfully and have more babies than usual, eventually leading to a whole new strain. The zooplankton of the ecosystem. But then if that becomes common, it may be worth it to produce a parasite to the parasite—defecting twice from the end. The bigger the possible rewards, the more layers of strategies will be viable. Tit for tat goo is unstable—plants quickly grow herbivores, and herbivores can sometimes grow predators.
And that’s just iterated prisoner’s dilemma. Add in more dimensions, multiple equilibria… things could get pretty complicated.