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One thing arguing against this is that there was little free atmospheric oxygen, and thus little ozone. According to Nick Lane in his book, "Oxygen", UV light

One thing arguing against this is that there was little free atmospheric oxygen, and thus little ozone. According to Nick Lane in his book, "Oxygen", UV light at the surface of the earth was 30 times greater then than now. Life has had a lot of time to build up mechanisms to protect against UV light [1], including sophisticated dna repair mechanisms and creating sophisticated antioxidants and regulation mechanisms. But at the dawn of life, whatever self-catalyzing reaction which constituted the first replicators would have been extremely fragile and unlikely to tolerate baking as you suggest. [1] In David Goodsell's book "The Machinery of Life", p.112, he mentions that when you stand in the midday sun without sunblock, UV light can cause adjacent cytosine and thymine rungs on the dna to cross link to each other. A repair mechanism sweeps the dna looking for this exact bond to unlink it before it gums up normal dna transcription activity. How often does it happen? 50 to 100 times per second ... per exposed cell.

photojosh 7y ago
Thanks for the book recommendations— right up my alley as I very much enjoyed Lane's "Vital Question" too.
- tasty_freeze 7y ago
  The full title of the first book is "Oxygen, The molecule that made the world", and was published in 2002. I'm not sure how much things have changed in the past 17 years, but presumably it is mostly still up to date. The first half of the book is about the history of oxygen on the planet and interesting details on how we can know it. The second half of the book is about oxygen processes on life mostly at the cellular level but also some at the whole-organism level. The book is pretty dense but it is fill with enough interesting ideas, such as why it is believed that cells had developed the ability to produce antioxidants before there was much free atmospheric oxygen. There is a discussion of how can it be that at every cellular division there is a certain fraction of transcription errors, yet the germ line still can pass on for billions of generations and still produce a healthy population.
fergalish 7y ago
Thanks for the reference, will try to look it up. I guess here I'm referring to the passage in the linked article that says: "...simple [chemicals] spontaneously polymerize and self-assemble into [bigger chemicals] when dried at moderate temperatures followed by rehydration."

photojosh 7y ago

Thanks for the book recommendations— right up my alley as I very much enjoyed Lane's "Vital Question" too.

tasty_freeze 7y ago
The full title of the first book is "Oxygen, The molecule that made the world", and was published in 2002. I'm not sure how much things have changed in the past 17 years, but presumably it is mostly still up to date. The first half of the book is about the history of oxygen on the planet and interesting details on how we can know it. The second half of the book is about oxygen processes on life mostly at the cellular level but also some at the whole-organism level. The book is pretty dense but it is fill with enough interesting ideas, such as why it is believed that cells had developed the ability to produce antioxidants before there was much free atmospheric oxygen. There is a discussion of how can it be that at every cellular division there is a certain fraction of transcription errors, yet the germ line still can pass on for billions of generations and still produce a healthy population.

fergalish 7y ago

Thanks for the reference, will try to look it up. I guess here I'm referring to the passage in the linked article that says: "...simple [chemicals] spontaneously polymerize and self-assemble into [bigger chemicals] when dried at moderate temperatures followed by rehydration."