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by josephpmay 3037 days ago
I feel like this article is pretty misleading in terms of the context and significance of the research. Inserting ancestral genes in extant organisms is a well-accepted approach to studying evolution. Evolution happens because of environmental pressure and random luck (mutations). There's no deterministic factor of evolution, and it's weird that the article tries to present it that way.
3 comments

Just because evolution is governed by randomness doesn't mean you can't make educated predictions about how an organism will evolve (at least given a set of otherwise constant environmental pressures, which is far from assured in the article's E Coli experiment). This is the whole premise behind convergent evolution: https://en.wikipedia.org/wiki/Convergent_evolution
I completely agree. I think this is an excellent way to study evolution. I just don’t see anything particularly novel in the research (not saying it’s not deserving to be studied or published- But I don’t get why it was presented the way it was in the article other than drumming up publicity)
You can make a prediction about what not how. Set things up and E Coli will develop antibiotic immunity, repeat the experiment 100 billion times and you might see 1+ billion different solutions. Insert fragments of a solution and repeat the experiment and you increase the odds to get the same solution, but the original solution space was still vast.

Consider, we say cancer mutates to disable specific genes, but not how those genes are disabled because it's outcomes not methods that are so common.

> repeat the experiment 100 billion times and you might see 1+ billion different solutions

You won't, though. There has been some excellent research on this done by amongst others Burmeister and Meyer in the Lenski group. Evolution is 'channelled' into certain solutions by its previous history and the process of co-evolving with other species.

That simply means some solutions are more probable than others, but there is a very long tail. Or at least as extrapolated from computer simulations.
Sure. It's still a game of chance. However, evolution is not random in the purest sense. Evolution itself skews the distribution of the kind of mutations you see.

For example: on of the papers by the Lenski labs show that the lambda phage evolves a certain defense mechanism very reliably in duplicated studies, despite it requiring several very specific mutations.

Random does not mean a uniform distribution. Toss 2 six sided dice and 2's and 12's are uncommon. But it's still a random process.

Also, saying you often get some set of mutations may be likely if subsets of those mutations provide advantages or there is some process that makes those mutations more likely.

Not true. Optimization of chemistry is going to happen unless explicitly hindered by something else. Here, they basically crippled a protein that increases the fidelity of protein synthesis, so there's a fitness advantage to any bacteria that can increase the effectiveness of the ancestral version. It wouldn't matter if the bacteria were in a swamp or someone's intestines or a petri dish - better protein synthesis is always better.
I mean, there is no determinism in so much as the universe is chaotic, but we have evolved methods to nudge evolution into certain, helpful directions. For example mate selection guides evolution. Even aspects like lifespan influence gene flow. There is a hyper system that is smarter than mere random chance.