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AI Revolutionized Protein Science, but Didn't End It

quantamagazine.org

31–39 of 39 posts

Re: AI Revolutionized Protein Science, but Didn't End It

#31
post #4
post #3

Weird article. It mentions multiple times that ~”the protein folding problem is solved” as well as multiple instances of ~”but there are limitations to this technique and it is often missing crucial details”. It really is difficult to conceptualize these highly nonlinear problem spaces, like protein folding, until you attempt to work with them. Many in software development have an intuitive understanding of the diffi…

> Protein folding is still an unsolved problem, and I’m dubious of the notion machine learning will ever solve it, but hopefully we get some helpful science out of it. As a working hypothesis, protein folding assumes that a protein folds into the globally lowest energy configuration. And that's a good assumption for a start. However, nature isn't magic and can't magically solve global optimisation problems. If there'…

The working hypothesis you described was considered fairly obsolete some time ago. The current model is much more "most proteins fold to kinetically accessible states". The assumption of global lowest energy led to a lot of wasted effort and misled computer scientists. But along the way to this understanding we learned an awful lot about the forces that affect folding- see for example "hydrophobic collapse".

Re: AI Revolutionized Protein Science, but Didn't End It

#32
post #13

Earlier quoted context omitted.

It really depends on the context; (Some) LLMs look impressive specifically because the error rate is comparable to a high score on an exam… the mistake is that even if it was a straight-A student (it's too alien to be that) then it would still only be a student, and we don't put fresh graduates in charge of everything important. I don't have the domain knowledge to even guess how good 90% is in molecular biology rese…

> we don't put fresh graduates in charge of everything important. We put dribbling halfwit morons in charge of everything. I'm thinking of Liz Truss as UK Prime Minister, but I'm sure most countries have their own examples.

"Anything" != "Everything", and examples like the Iceberg Lady are usually followed with "and that's why they went bankrupt, so don't do that".

Re: AI Revolutionized Protein Science, but Didn't End It

#33
post #11

Earlier quoted context omitted.

> That the results the machine learning techniques provide are still nondeterministic. I think I know what you are trying to say, but 'determinism' or not isn't the problem. You can run machine learning methods completely deterministically: just use a pseudo-random-number-generator (and be careful about how you seed it, and be wary of the problems with concurrency etc). > If the provided solution also came with a met…

> Sounds like woo. O, definitely woo. I tried to make that explicitly clear by using “hypothesis” and “appearance”. My hypothesis is less “optimization solutions == consciousness” and more positing that our brains, “action potentials” was meant as cheeky shorthand for the human brain, use an “optimization solution” that we identify as “consciousness”, or as you put it “sentience”. But to quote South Park, “and I base…

You might like https://scottaaronson.blog/?p=735 for some speculation on those topics with slightly more technical grounding. Direct link: https://www.scottaaronson.com/papers/philos.pdf

Especial the chapter: 'Computational Complexity and the Turing Test'

Re: AI Revolutionized Protein Science, but Didn't End It

#34

Earlier quoted context omitted.

The article states: "However, in about 10% of the instances in which AlphaFold2 was “very confident” about its prediction (a score of at least 90 out of 100 on the confidence scale), it shouldn’t have been, he reported: The predictions didn’t match what was seen experimentally." This is the number one issue with using the so-called "deep learning": the results may be completely wrong and there is no known way to pred…

This seems like it should be bigger news than it is?

Oh it will be big enough when the AI stocks bubble pops.

Re: AI Revolutionized Protein Science, but Didn't End It

#35
post #31
post #4

Earlier quoted context omitted.

> Protein folding is still an unsolved problem, and I’m dubious of the notion machine learning will ever solve it, but hopefully we get some helpful science out of it. As a working hypothesis, protein folding assumes that a protein folds into the globally lowest energy configuration. And that's a good assumption for a start. However, nature isn't magic and can't magically solve global optimisation problems. If there'…

The working hypothesis you described was considered fairly obsolete some time ago. The current model is much more "most proteins fold to kinetically accessible states". The assumption of global lowest energy led to a lot of wasted effort and misled computer scientists. But along the way to this understanding we learned an awful lot about the forces that affect folding- see for example "hydrophobic collapse".

Thanks!

Re: AI Revolutionized Protein Science, but Didn't End It

#36
post #4

Earlier quoted context omitted.

> Protein folding is still an unsolved problem, and I’m dubious of the notion machine learning will ever solve it, but hopefully we get some helpful science out of it. As a working hypothesis, protein folding assumes that a protein folds into the globally lowest energy configuration. And that's a good assumption for a start. However, nature isn't magic and can't magically solve global optimisation problems. If there'…

I feel like there should be a much stronger effort to solve optimization problems with ML enabled guesses. It's arguably the most important problem to be solving to improve ML itself. Humans, for example, can provide extremely strong guesses by just eyeballing travelling salesmen problems without doing any calculations. If we could use ML to take a problem and guess how to reformulate it with 95% of the search space…

Human can mostly only do these kinds of guesses for traveling salesmen problems embedded in 2d Euclidean space. But we have pretty good heuristics for these cases to kickstart a solver, too. Give a human a general graph with arbitrary edge weights, and they'll be dumbfounded.

(I don't think you even have to go all the way to an arbitrary graph, I suspect a decent sized graph with edge lengths embedded in 3d euclidean space will already confuse humans. Definitely once you get to 4d.)

Re: AI Revolutionized Protein Science, but Didn't End It

#37

It is/was a brilliant piece of work ( Nobel prize level ) - however I think the impact is over-hyped - as somebody who has experimentally solved a protein structure - I can tell you knowing the structure doesn't necessarily help you understand the biology - not every structure is as functionally obvious as the structure of DNA for example. In terms of drug discovery - even assuming the models are as good as experimen…

“ knowing the structure doesn't necessarily help you understand the biology ” I think most everyone recognizes this, but also believes it is probably necessary to know the structure to understand the biology in the future. Ie a necessary yet insufficient advancement that is Nobel worthy.

> but also believes it is probably necessary to know the structure to understand the biology in the future

I don't agree. Biology is really about systems - complex networks of biological interactions. The physically structure of it's components aren't required to understand those interactions at the system level if you can simply measure the interaction directly ( rather than trying to predict it poorly from a structure ).

Re: AI Revolutionized Protein Science, but Didn't End It

#38
post #36

Earlier quoted context omitted.

I feel like there should be a much stronger effort to solve optimization problems with ML enabled guesses. It's arguably the most important problem to be solving to improve ML itself. Humans, for example, can provide extremely strong guesses by just eyeballing travelling salesmen problems without doing any calculations. If we could use ML to take a problem and guess how to reformulate it with 95% of the search space…

Human can mostly only do these kinds of guesses for traveling salesmen problems embedded in 2d Euclidean space. But we have pretty good heuristics for these cases to kickstart a solver, too. Give a human a general graph with arbitrary edge weights, and they'll be dumbfounded. (I don't think you even have to go all the way to an arbitrary graph, I suspect a decent sized graph with edge lengths embedded in 3d euclidean…

My point is not that we should mimic humans. My point is that there's probably learnable but inexplicable heuristics you could learn for generally solving gradient descent problems just by the formulations on their own that a neural net would be good at.

Re: AI Revolutionized Protein Science, but Didn't End It

#39
post #5

Great article, covers well both the achievements and the shortcomings. It's crazy how many people write about these kinds of AI developments while completely skipping over anything like the following: > The “good news is that when AlphaFold thinks that it’s right, it often is very right,” Adams said. “When it thinks it’s not right, it generally isn’t.” However, in about 10% of the instances in which AlphaFold2 was “v…

> However, in about 10% of the instances in which AlphaFold2 was “very confident” about its prediction (a score of at least 90 out of 100 on the confidence scale) I wonder what that confidence score means... If it is 90% probability, then we'd expect it to be wrong 10% of the time

If you're actually interesting, you can read about the scoring here:

https://www.ebi.ac.uk/training/online/courses/alphafold/inpu...

Long short, it's a lot more complex than just % probability the atoms have proper Cartesian coordinates.

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