It still seems pretty outlandish at an interstellar scale. Life would have to survive ejection, survive space, actually hit a target, survive injection, and be compatible with the new environment.
All that and life still has to evolve somewhere in the first place.
Billions of chances might not even get you out of the star system. And even with 100 million years of time you might not find another star system. If you do, you need to go into orbit or you’re nearly guaranteed to not hit anything. And you’re most likely to hit either the host star or a gas giant. If you do manage to hit a rocky body with water and survive, you still have to land in a place that gives you access to that water. The odds are literally astronomical.
Of course water by itself isn’t enough. You’ll also need the correct chemical makeup, pressure, light, temperature range, etc. And you’ll need enough energy and materials to reproduce enough that random mutations can bootstrap an ecosystem before your monoculture consumes all the food and starves itself to death.
Hot spring bacteria won’t survive the arctic and vice versa. Whichever specific bacteria make the trip have to find themselves in an environment specifically non-hostile to that bacteria.
Might is a fine word, but eventually the odds are so unlikely you have to conclude its impossible or at least that independent abiogenesis is more likely. It’s also possible to take a step back and consider molecular panspermia or other theories.
>Hot spring bacteria won’t survive the arctic and vice versa.
No but can adapt, any discussion about it is just plain stupid, the chance is small but give the mass of chances over time it's not that small anymore, you know like intelligent life on another planets.
Yes, there are even competing theories of DNA versus RNA as the sort of precursor self-replicating molecules. See "RNA World" and "Primordial Soup" theories.
RNA makes for an interesting candidate because of enzymatic activity. Similar molecules could enzymatically consume, build, and "compete" with one another.
To my knowledge, there are many computer simulations, but I don't know an exact figure for "how long would it take given X (some axiom of the state of the Earth). Here's a paper I found quickly. I promise I didn't choose that institute/university on purpose.
The fossil record indicates life on Earth appeared no later than about 800,000,000 years after it first formed, and possibly much sooner.
While there’s no real evidence for panspermia, it is a fun topic to read about. I recall one hypothesis is that DNA (or RNA) based life evolved shortly after the Big Bang (500,000 years?) when the universe was a balmy lumpy-gas bath of 0-100C. If this were true, it would follow that life is as pervasive as the cosmic background radiation and we should expect to find it in every crevice. Mind-bending.
> I recall one hypothesis is that DNA (or RNA) based life evolved shortly after the Big Bang (500,000 years?) when the universe was a balmy lumpy-gas bath of 0-100C. If this were true, it would follow that life is as pervasive as the cosmic background radiation and we should expect to find it in every crevice. Mind-bending.
That's pretty unbelievable, since at that time stars hadn't formed to create heavier elements, so the elements available were hydrogen, helium, and a little bit of lithium. DNA is mostly carbon and nitrogen.
All that and life still has to evolve somewhere in the first place.