New finding: 600M years ago, a single mutation changed everything

There is a common objection?

This is just false. Evolutionary theory requires no such thing and there's plenty evidence that each step towards the evolution of things like the eye provides marginal advantage to the organism even though it's not fully an eye.

Luckily machine learning came along and has shown empirically that the solution is to increase the number of dimensions. Our tiny neural nets of the 90s also got stuck in local maxima. But when we could finally make huge and deep networks, the problem more or less disappeared.

I believe this is the real solution to the local maxima problem in evolution. Real evolution works with a massive number of parameters, which means exploration of the problem space doesn't get stuck in local maxima, just as it doesn't in Deep Learning. When the number of tweakable parameters outstrips the dimensionality of the problem space then there is always some angle pointing up out of the valleys.

This is a different, and I think more general way of expressing the typical counterargument which you explained. "There is always some angle pointing up" is a more general way of saying "just one mutation is usually enough to create a functional prototype".

In particular, this article was of interest to me simply because of how grand a claim it makes.

In general, grand claims are something to approach with skepticism, because of laws of probability number 35, which states that: "few complex non-linear phenomena have a beautifully simple explanation, and if a grand claim purports to be such an explanation, then it most likely is not such an explanation".

It is worth reading law 36 of probability as well: "the maker of a grand claim is more likely to be a 'journalist' or a PR department person, than a scientist".

How do the laws of probability hold up? Pretty darn well, I'd say.

Here's the abstract (by the way, eLife IS an open source journal, so the journalist had no excuse here):

> To form and maintain organized tissues, multicellular organisms orient their mitotic spindles relative to neighboring cells. A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues. Here we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism. The complex was assembled through a series of molecular exploitation events, one of which – the evolution of GKPID’s capacity to bind the cortical marker protein – can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID. This change revealed and repurposed an ancient molecular surface that previously had a radically different function. We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals.

Key takeaways:

1) "A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues"

Explanation: in this sentence, the scientists are carefully pointing out where the 'thing' (a protein domain) they are going to make a claim about fits into the biological picture. No, there isn't one superhero -- there's a carefully choreographed concert that their 'thing' is a part of.

2) "we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism"

Very cool. Simple statement. Interesting, but no grand claim.

3) "The complex was assembled through a series of molecular exploitation events, one of which – the evolution of GKPID’s capacity to bind the cortical marker protein – can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID."

Again, they reiterate how there was actually a bunch of things happening ("a series of molecular exploitation events"), ONE of which is the cool one they want to talk about.

4) "This change revealed and repurposed an ancient molecular surface that previously had a radically different function."

If you were wondering what's cool, this is what's cool.

5) In conclusion: "We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals."

Hmm...no grand claim finishing claim made regarding how this ONE thing changed EVERYTHING. Again, we are reminded of the whole picture: "so yeah guys, here's how this protein function, which is essential (because it's part of a super complex dance number) for so many living things, probably came about".

I'm going to go commission a gold filigree copy of the laws of probability.

What do you think of it? Is it serious enough? Because I think there is an obvious flaw in it, the question: why are these mutations linked?

The answer to this proposition is that the fact we aren't aware of the evolutionary advantages which were obtained en route doesn't mean there weren't any.

The feathered wing is very complex and it won't fly until it has fully evolved, for example -- but as we learned quite recently, feathers evolved (and were an evolutionary advantage) because dinosaurs needed to stay warm. Birds can fly because a feather which is efficient at capturing air and keeping a giant lizard warm also turns out to be very efficient at pushing air and keeping a proto-avian aloft.

This is not true, the question isn't whether neutral changes can spread, but simply what percentage of molecular changes that spread are neutral. In fact I think that molecular evidence has shown pretty convincingly that on the genome scale most changes are neutral, vindicating the Neutral theory of evolution:

https://en.wikipedia.org/wiki/Neutral_theory_of_molecular_ev...

I think it's more the case that things may spread if they don't have any disadvantage (like causing death).

That doesn't sound right at all. Look at the some of discussion of the 'Irreducible Complexity' examples. https://en.wikipedia.org/wiki/Irreducible_complexity#Stated_...

Genes which do not confer any advantage are just as likely to spread as ones that do. Evolution doesn't select for advantages, it selects against disadvantages. Evolution is just an emergent property of death.

Allow me to quote [topic: 'The missing steps to complexity', page-45]:

"In The Origin of Species Darwin made the point that that natural selection actually predicts that intermediates should be lost. In that context, it is not terribly surprising that there are no surviving intermediates between bacteria and eukaryotes [e.g. plants, humans]. What is more surprising, though, is that the same traits do not keep on arising, time and time again -- like eyes.

We do not see the historical steps in the evolution of eyes, but we do see an ecological spectrum. From a rudimentary light-sensitive spot on some early worm-like creature, eyes have arisen independently on scores of occasions. That is exactly what natural selection predicts. Each small step offers a small advantage in one particular environment, with the precise advantage depending on the precise environment. Morphologically distinct types of eye evolve in different environments, as divergent as the compound eyes of flies and mirror eyes of scallops,or as convergent as the camera eyes that are so similar in humans and octopuses. Every conceivable intermediate from pinholes to accommodating lenses, is found in one species or another. We even see miniature eyes, replete with a 'lens' and a 'retina', in some single-celled protists [e.g. amoeba]."

However, it didn't.

Best i can tell, all that is needed for something to be carried forward is for it to not be a hindrance.

Thus, a proto-wing could very well linger for generations without going anywhere simply because it does not hinder the lineage's survival.

Never mind that the planet has not been the shape we see it in for the entire time.

Google how the eye evolved, it didn't just mutate it was a series of slow gradual mutations.

What you are suggesting goes against evolution theory (which is ok with proper evidence)

It's a mutation theory which is hard to find a lot of info on and I can't find the proper name of.

But it is considered incorrect.

Consider a growing multicellular organism. It grows by a process of cell division. Each division turns one cell into two adjacent cells. The structure it ends up with will depend on the orientation of those dividing cells (you'll tend to get growth "along the axis of division", so to speak).

A wide variety of multicellular organisms have a mechanism that orients cells according to features on the outside of neighbouring cells. (It "mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues", as the abstract puts it. The "mitotic spindle" is a structure involved in cell division, also called mitosis. It's mostly made out of long thin things called microtubules, and its job is to separate the chromosomes for the two new cells, which it does using "motor proteins". The cell cortex is the inner surface of the boundary of the cell.)

One part of this process is the way in which a protein involved in the mitotic spindle attaches itself to that thing on the cell cortex. The relevant bit of that protein is called the "guanylate kinase protein interaction domain" or GK_PID for short. A protein interaction domain is a bit of protein that interacts with other things; multiple different proteins can contain instances of the same interaction domain, just as multiple different programs can contain (say) the same code for computing SHA-256 checksums.

The paper reports evidence that a single mutation enabled the GK_PID to attach itself to the marker on the cell cortex. ("The complex was assembled through a series of molecular exploitation events, one of which – the evolution of GK_PID’s capacity to bind the cortical marker protein – can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GK_PID."

So. This doesn't say that multicellularity was enabled by a single mutation. It says that one small but important part of a process that's necessary for complex multicellular organisms was enabled by a single mutation. Still pretty cool, but the journalistic science->hype conversion machine is clearly operating as usual here.

Read this comment of bmer about the original research article: https://news.ycombinator.com/item?id=10884255

[0] [Or to be more precise, IIRC the transition from bacteria to eucariota is more difficult. I'd worry about that step instead.]

I didn't read the paper, but probably this technique: https://en.wikipedia.org/wiki/Molecular_clock

That and the rise of multi-cellular life marks the beginning of the Cambrian explosion (542M years ago). That gives 60M years for the mutation to spread and specialize.

Tell that to a geologist or an astrophysicist and you'll be laughed out of the room. There's plenty of evidence of timescales in the millions and billions of years.

Geologically? Not at all. It's 0.000022% of the age of the Earth.