Cells divide and make new cells, is all life on Earth rooted in one super ancestor cell? Or are there parallel paths to cell creation?
Cells divide and make new cells, is all life on Earth rooted in one super ancestor cell? Or are there parallel paths to cell creation?
We haven’t even fully grasped the system of self-propagating chemical reactions that increasingly met more criteria of “life” before a single cell was formed. Everything suggests that the process is super rare so it’s safe to assume it only happened successfully once. Tectonic plate movement has erased geologic evidence of conditions around the origin of life but given that all known forms of life share the same basic elements (H, C, N, O) and reactions, it is harder to argue against a single origin than for it.
It’s safe to assume that it has happened successfully at least once.
The universe is vast and the cosmos even moreso, and while we may indeed be the only form of life in this universe that can wonder about and traverse space, we know with 100% certainty that this universe has the characteristics to produce life.
We cannot be certain or safely assume that it’s only happened once. The amount of space we’ve explored even with our telescopes is about the same amount as a cup of ocean water versus the ocean.
See post title
Ah, gotcha. You were being very specific about Earth. My bad.
I think all we can assume is that life as we know it became dominant, either by sheer luck or by outcompeting other variants. We can’t reasonably discard that life happened more than once here.
It might seem like an astronomically rare event because that’s the only kind of life we know.
It’s not only the same elements, but the fact that all forms of life incorporate self-replicating DNA molecules.