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Comment by umvi | Hacker News Reader

I am biased by my religious beliefs, but I've always struggled with the idea that abiogenesis could spontaneously occur in "just" a few billion years on earth. A few billion seems like not enough time. Even the simplest forms of life are mind bogglingly complex.

Of course, it's a few billion years scaled across >1 life-friendly planets (since it only has to happen on 1 of them), but still just seems like not enough monkeys and typewriters in the given timeframe to produce something as astonishingly complex as life, let alone Shakespeare.

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So this comes up a lot. I often think about the case of protein structures.

Let's consider a protein of 100 amino acids; although most proteins are in the 200-500 range (IIRC) it makes the maths simpler. Even for such a short sequence, the probability of coming up with one specific sequence at random is incredibly small - 20 to the power of 100 or 1.267651e+130.

The simple answer to this apparent puzzle ('how did proteins evolve from random mutations') is of course that it did not happen like this. Not at all like monkeys typing out scripts and a human checking if they have produced a Shakespeare play yet.

In fact, there are multiple solutions to the same problem - in the analogy, this would be like multiple different versions of the same play being just as good as the other. Even better for evolution, you can - in a sense - put on a version of a play that is pretty bad, but just good enough to put in front of an audience. In other words, some enzymatic functionality can be better than none.

In this way, an evolutionary system can build up complexity by making parts that are _good enough_ and are roughly equivalent to other parts that can be replaced gradually. Combine this with the massive parallelism and the scale of the molecular world, and a billion years can accomplish a lot.

Except abiogenesis didn't occur on Earth in few billion years, but within half to billion years after Earth was habitable. All the other features of life have taken four billion years to arise through evolution. It is like looking at current cars and wondering how they could come from nothing where had to look at the original cars and hundred years of improvement.

Abiogenesis really only need to explain how the first life arose. It could have been really simple since it got out competed by more sophisticated descendant that took over planet and left no trace of original life. We don't know how it happened, if required lots of random chance or if there was a replication step that made if go faster. We know that evolution can make complicated stuff over time.

> A few billion seems like not enough time.

Where would you get an intuition about how much time a billion years is? Or for what is "mind boggingly complex" and what not? How many eons have you lived? People who claim it is possible have better arguments than "to me it seems". Do you have a number for "this would seem to me as enough time"?

Do you also struggle with the idea of a poll being close to the truth when done on a sample of 1000 persons, out of tens or hundreds of millions? Math and science are often not intuitive. But they work.

Have you ever considered the possibility of supernaturally guided evolution. Always seemed like an interesting possibility to me. So God creates an incredibly beautiful concept that life comes from. Seems like one of the most probable solutions to how astonishingly unlikely abiogenesis would be.

This is a very computer science and not scientific response, but I look at the Game of Life, and it makes me realize that little patterns naturally form everywhere. Biology is just a little pattern that wants to replicate and survive and that doesn't have to mean intelligently.

> Biology is just a little pattern that wants to replicate and survive

I don't really see biology as being a "little" pattern. To me, looking at the jump from replicating molecules in chemical soup to single cell organisms is like looking at the jump from an abacus to an Intel i9 processor.

> the jump from an abacus to an Intel i9 processor

Call it 75 years (1942 - before electronic computers to 2017 - first i9) which is about 39M minutes. Assume human innovation can work on an minutely cycle[0] and you've got 39M iterations from "no electronic computers" to "Intel i9".

I'd put decent money on there bring several orders of magnitude more chemical reactions than that per second in the primordial soup (good conditions for fast reactions and there was A LOT of it.) And it had about half a billion years (fifteen quadrillion, seven hundred seventy-eight trillion, eight hundred billion seconds) to cook before things really started happening.

Statistically, it was likely.

[0] Obviously optimistic but giving parallelism a chance.

I would guess that abiogenesis is often framed around randomness as a strategy to argue for its implausibility. Of course, a completely random system is unlikely to produce enough coherence to convince anyone that it could be possible.

But in reality, the universe is full of patterns. The laws of physics are not random. Water behaves in very specific ways. Our planet revolves around the Sun in 365 day intervals. The planet rotates every 24 hours. Even out of these two interlocking patterns, you can see how energy delivery to the surface of the planet could result in mechanical and chemical cycles that may result in non-random mineral formation, concentration gradients, and thermal dynamics.

Scientists argue that abiogenesis is a result of inherently chaotic but non-random processes, not a hypothetical probabilistic scenario like monkeys with typewriters.

Who said you had to junp to single celled organisms first? One of the oldest displays at a science museum I remember was very simple. It was basically a rubber sheet attached to the top of a spinning pole resmebling a folded umbrella without the spines. There was a adjustable knob you could play with to adjust the speed that it spun. It would start from zero. Versus interestingly to me, the exhibit demonstrated that at certain speeds the dangling edge of the rubber sheet would form nice sine waves at certain speeds. It might be chaotic at first but eventually, given just the right amount of energy to spin, the wave would appear. If you sped it up or slowed it down, sometimes the wave would collapse, but if you hit another natural frequency, it would eventually snap into a larger or smaller amplitude with a greater or lesser amplitude. My take away was that if there is enough energy and repetition to almost anything, eventually patterns will arise. And if you let them do that long enough, then even in imperfect environments, relatively stable outcomes would occur. Much like life in my opinion. Have enough chemicals and energy thrashing around long enough in a cycle, and enough adverse selection against all those structures, eventually some structures will emerge and self-reinforce. Doesn't gotta start with cells, just molecules.

We're in the universe where it did happen.

I don't think religion has anything to do with it. Statistics and increasing entropy. Now, where you go from there might take you to religion, and so I'd argue that modern science often has arguably more to do with the religion of atheism than with reason since it's mostly based on certain axioms. I'm not saying we can't derive science off of theories, but as long as the bases are only asserted, you can derive proofs to come to any conclusions and speaking up about this seems to quickly get you disqualified in academia.

Frustrating that we’ve seem to built thousands of assumptions on an unproven base.

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