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The origin of life remains a profound mystery. The more we investigate, the further we push back its beginnings, suggesting that we may eventually need to searc
by maitola 2y ago
The origin of life remains a profound mystery. The more we investigate, the further we push back its beginnings, suggesting that we may eventually need to search beyond Earth for answers. Since the Miller-Urey experiment, which successfully synthesized amino acids, we have made little progress in understanding the exact processes that led to the emergence of life. How were RNA and DNA formed? How did the first cell come together? What were the necessary timelines, energy sources, and chemical conditions? Is Earth uniquely capable of generating life, or is life, in its most basic form, a common feature of the universe? The formation of water involves processes akin to supernovae; perhaps the genesis of life requires a similarly extraordinary scale of events, or even more? We need to find out.
- Jedd 2y agoThis sounds a bit defeatist, and seems to ignore a large swathe of work that has happened since 1952 (the Miller-Urey experiment). For example - this experiment was conducted a year before the structure of DNA was discovered / published - so it's quite a bold claim to say 'origin of life' research stalled in 1952. To your first, second, and third questions - I can highly recommend Nick Lane's book 'The Vital Question' [0]. To some extent, I think he also spoke to your fourth question in that book - but I read 3 or 4 of his books around the same time, so my memory is fuzzy. Either way, his hypothesis around alkaline thermal vents is hugely persuasive & compelling. I'm really struggling to understand what you mean by the claim 'formation of water involves processes akin to supernovae' - do you just mean you need a star to explode before you get heavier elements (including Oxygen)? [0] https://en.wikipedia.org/wiki/The_Vital_Question https://en.wikipedia.org/wiki/The_Vital_Question
- maitola 2y agoI completely understand your struggle and wonder why this fact isn't more widely discussed. The vast majority of water on our planet (and in the solar system) was formed through either stellar formation or supernova events. During these events, an outward wind of particles collides with nearby material, forming new molecules such as water. Any other process of water formation is negligible in comparison. https://en.wikipedia.org/wiki/Water https://en.wikipedia.org/wiki/Water (see Distribution in Nature) https://web.archive.org/web/20000116054013/http://www.news.harvard.edu/gazette/1998/04.23/DiscoverofWater.html https://web.archive.org/web/20000116054013/http://www.news.h... Thank you for the books recommendations, I’ll check them out.
- Jedd 2y agoOh, okay, so that's what you meant. There's no reason to think other solar systems wouldn't have water, in that case, as there's little that's unique about our garden - or, from a slightly different angle, we shouldn't be surprised to find ourselves living in a place that has water.
- maitola 2y agoOn the contrary, I don’t want to sound defeatist. We’ll figure this out sooner or later, and it’s actually quite exciting, after all, we didn’t just come from a little pond! The discovery of DNA, RNA, and many other cellular mechanisms has greatly improved our understanding of how life works. This knowledge helps us formulate theories about the origin of life. However, as of today, no one has, for example, taken a Miller-Urey like experiment and spontaneously generated DNA.
- Jedd 2y agoWell if RNA was a (necessary) precursor to DNA, some experiments that attempt to replicate aspects of a deep alkaline thermal vent have already been conducted - you can get, albeit very short, strings. But the obvious problem is in trying to replicate a chemical soup and structure under high pressure, that doesn't exist any longer, and then run experiments to try to replicate outcomes of a natural experiment that lasted hundreds of thousands of years. The idea that DNA needs to be spontaneously generated in order for us to be confident that we understand how DNA came to be is misplaced.
- maitola 2y agoThe point is that until we understood stellar mechanics and observed the formation of water in stellar events, we didn’t know where water originated. This suggests that we should not limit our thinking to Earth-based mechanisms when considering the formation of RNA and DNA, which are molecules orders of magnitude more complex than water. Another problem is that the earliest fossils are 4.3 billion years old, while Earth itself is 4.6 billion years old. This means that life must have originated within the first 300 million years of Earth’s existence. What was this unique environment that enabled the creation of RNA, DNA, and cells? And why did this magical environment disappear in the subsequent 4.3 billion years? We don't need to generate it spontaneously, but we do need to understand the mechanism precisely. Filaments alone (can you share the relevant research on this?) are not enough. We need to understand exactly how DNA, RNA, and cells came into existence, just as we sought to understand the formation of water. Until then, we won't have the answer to the origin of life.