Theoretical origin of life: started with hydrogen cyanide (Introduction)

by David Turell , Tuesday, February 01, 2022, 19:10 (1026 days ago) @ David Turell

Another wild lab based theory:

https://www.livescience.com/first-life-on-earth-deadly-poisonous-gas?utm_source=SmartBr...

"Those early life-forms were almost certainly very different from modern-day ones. That's because modern-day life-forms require three macromolecules: DNA, RNA and proteins. Very roughly, our DNA stores information, the RNA transmits that information to manufacture proteins, and the proteins do most of the work of keeping life alive — including replicating DNA.

"This system is so interconnected that it's unlikely that it all appeared at once in its modern form. But primitive life still needed to perform the basic functions of life: store information, replicate itself and catalyze other chemical reactions.

"It's possible that RNA alone is capable of doing all three — definitely not as efficiently as the DNA-RNA-protein combo we have today, but it makes for a plausible starting point for life.

"If RNA can get going as a primitive form of life, then Darwinian evolution can take over, enabling more complex and more efficient biochemical processes to emerge. So perhaps to crack the origins of life on Earth, we just need a lot of self-replicating RNA. But where does the self-replicating RNA come from?

***

"...as the meteorites were delivering fresh supplies of hydrogen to Earth's atmosphere, those volcanoes were spewing tremendous amounts of carbon dioxide. Also, the oceans were much warmer than they are today, and they were constantly evaporating into the atmosphere. Lastly, undersea vents were leaking methane.

"As all those molecules built up in the atmosphere, lightning strikes and ultraviolet radiation from the sun provided the energy to shake things up a bit. In this case, those sources provided the energy necessary to form … hydrogen cyanide.

"That's right, hydrogen cyanide. The poisonous gas that can spell certain death for modern-day life may have been the most important molecule in the development of that same life.

***

"They found that during a 100 million year-long period some 4.4 billion years ago, the amount of hydrogen cyanide raining into ponds was enough to create high concentrations of adenine, one of the components of RNA.

***

"Eventually, as meteorites stopped dropping, the hydrogen levels in the atmosphere fell. But by then, enough adenine may have been created to begin the formation of RNA strands, which may have triggered the exploration of self-replication and the beginning stages of life, the researchers explained.

"If it seems like a lot of steps, it's because it is. Even though these early life-forms would be considered highly primitive from the perspective of modern life, self-replicating and catalyzing RNA strands are already extremely complex molecules, and their appearance necessarily includes a lot of precursor reactions.

"No matter what, something special definitely happened on Earth long ago, and it may have started with hydrogen cyanide."

Comment: One 'possible' tiny step and ignoring all the other steps mentioned in the article, the researchers still hope for a magic introduction of life naturally. So they estimated somehow enough hydrogen cyanide to form adenine, just one minor necessary step and the article is ecstatic