[nobody9999]

>For example, this theory sti doesn't answer the question how they came into existence in the first place. It's certainly not obviously better than assuming they suddenly appeared on another planet and then transported to earth..

Not sure what you're getting at WRT amino acids. Amino acids form due to the particular chemistry of carbon (what we call "organic chemistry"[1]), and they do so wherever both energy and the building blocks of amino acids exist. No planet required.

This was shown pretty well by the Miller-Urey experiments[2] as well as the discovery of amino acids in interstellar molecular clouds[0].

So...Amino acids can (and do) form wherever the raw materials and energy exist. That's the "how".

[0] https://physicsworld.com/a/amino-acid-detected-in-space/

[1] https://en.wikipedia.org/wiki/Organic_chemistry

[2] https://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment

[mac01021]

So then they'd have formed on earth - no panspermia required?

[Hani1337]

planet is an amalgam of rocks and minerals, heat is provided by the sun, water could have been of extraterrestrial origin, and then enters fungi using heat and humidity to develop mycelium, mycelium turns minerals into compost with enzymes, space dust introduces bacteria which evolves through thermal vents a/biogenesis, and voila, you have life. We do know that before vegetation, Earth had fungi structures made of half rock, half fungi flesh, and they probably evolved into actual trees. At the same time, lichen spread from underwater to the surface of the Earth. Fungi released CO2, creating an atmosphere for plants to develop. The rest is evolution.