for those impatient like me (aaargh!):
> Darwin was proposing that life began, not in the open ocean, but in a smaller body of water on land, which was rich in chemicals
> Darwin was proposing that life began, not in the open ocean, but in a smaller body of water on land, which was rich in chemicals
Another consequence of free oxygen is the formation of an ozone layer, reducing the UV flux at the surface. I guess the significance of that depends on whether UV helped or hindered the process.
For example from https://en.wikipedia.org/wiki/Amino_acid
> These are all L-stereoisomers ("left-handed" isomers), although a few D-amino acids ("right-handed") occur in bacterial envelopes, as a neuromodulator (D-serine), and in some antibiotics.
> Although D-isomers are uncommon in live organisms, gramicidin is a polypeptide made up from mixture of D- and L-amino acids. Other compounds containing D-amino acids are tyrocidine and valinomycin.
Some bacteria can produce the D- version of the amino acids, and use them in peptides that are natural antibiotics because other bacteria don't know how to destroy them. (Anyway, some other bacteria can are resistant, because they developed a way to destroy them.)
Also, it probably requires an ambient with a lot of methane or some similar compound, but probably other bacteria are eating the methane, or oxygen is destroying it.
>In 2019, researchers in Germany made all four [RNA bases] at once. They placed simple carbon-based chemicals in hot water on a mineral surface and subjected them to repeated wet-dry cycles.
And no one else has been able to do that under other conditions such as undersea vents.
(I guess that would then kick off RNA world https://en.wikipedia.org/wiki/RNA_world)
> “But it’s something that could be trying to happen even now.”
Could be happening on earth still or other planets he meant?