Bobthehobnob t1_jd5rlyn wrote on March 22, 2023 at 12:53 AM

Reply to comment by Brain_Hawk in A crucial building block of life exists on the asteroid Ryugu. Uracil, a component of RNA, was found in a sample collected by Japan’s Hayabusa2 spacecraft. by Science_News

There's the Urey-Miller experiment which tried to recreate early earth atmospheric conditions, and they succeeded in making DNA and RNA (and also proteins and polysaccharides iirc) from methane, water, hydrogen and ammonia, but I think people later remarked how the early earth atmosphere probably didn't have the conditions required by the Urey-Miller experiment to actually be able to make these molecules.

https://www.science.org/doi/10.1126/science.1161527?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

I'm not an expert on early life origin work, but as a biologist it definitely drew my attention to see uracil being discovered on an asteroid, as AFAIK it's pretty much only formed in nature through biological methods (at least with the current earth conditions it is, as the earth has changed quite a lot over the past 4.5 billion years, so it is possible at one stage that it was formed non-biogically).

Brain_Hawk t1_jd5xtiu wrote on March 22, 2023 at 1:39 AM

That's really interesting. The article and.somethibg else (I forget now) made me presume it was naturally occurring. If it's largely biological how did it get to be part of RNA? Maybe a different molecule started it off?

Interesting those experiments on early dNA did not replicate. Undergrade was a long time ago so last I had heard it was probably all the rage. Of course, ever will we debate what conditions are the right conditions, etc.

Thanks for the informative post.