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Comment by vibrio | Hacker News Reader

I'm not sure bleach would be that interesting. It's like asking deer to evolve resistance to hunters' rifle bullets--it's too steep an evolutionary step.

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Is it though? Imagine a world in which the only agent of selection was hunters bullets. No sexual selection, no food shortage, nothing. In other words, an absolutely perfect deer breeding ground.

Place a billion deer in this environment and shoot them all. A few survive. Let numbers rise, and do it again.

Soon you start seeing deer with arteries and veins that are smaller, blood that clots faster. Maybe the deer themselves are smaller, or their internal organs are smaller but their muscles larger, fed by a larger number of smaller veins. Perhaps muscle density is higher to offer better protection. Bone and skull thickness increases.

Eventually you've got an animal with a small, very thick skull, with lots of angles to increase the likelihood of ricochet, a heart protected by layers of thick muscle and a reinforced, thickened ribcage. Veins and arteries are reduced in size so much that it's practically impossible to bleed out, immune system is in constant overdrive to fight infection, and the rest of the internal organs are either shrunken, duplicated, or hardened against piercing damage.

In any case, my point is, if we could set up an experiment with deer like we can with bacteria, I think it's likely that we'd be surprised at what's possible.

Well done on the deer analogy- I'm in over my head there. I appreciate and agree with your point, and think my original response was glib and not clear. Clearly, extremophilic archea have evolved to inhabit nearly every niche of the earth (Deinococcus radiodurans is a great example). The point I took from the video was not that bacteria are rapidly able to adapt to antibiotics, that’s been known as long as antibiotics have existed, but the observation of the instant in time when a bug figures out one of those discrete changes and its offspring thrive. I believe the scale and breadth of adaptations required to observe evolution of meaningful resistance to a universal denaturant such as bleach would be prohibitive. Bleach destroys at the level of protein chemistry, where as antibiotics are specifically toxic to bacterial structures. The wholesale changes would be required of the organism, rather than discrete mutations in the ribosome, cell wall, or other mechanisms known to drive antibiotics resistance-probably what you can see changing in the video. My awkward comment was intended to say I don’t think the scale and time frame of the video assay would not be amenable to the scale of the study for bleach resistance. You illustrate that same point in your comment. That said this is all knowable first-hand, as generating or isolating bacterial strains resistant to toxins is science one could do at home with probably less investment that homebrewing beer, although without the fancy movies.

Taking this discussion a step further: in the bullets/deer instance, you'd be more likely to evolve a primary lifeform that looked more like a tree or grass or slime-mold than a deer. That is, it either consists almost entirely of bullet-stopping material (wood), or is so lightweight that bullets don't effectively transfer energy to it (grass), or the structure is entirely decentralised such that a bullet, or even a hail of bullets, cannot disrubt the systemic function of the organism -- it simply absorbs the projectiles and functions around them.

A chlorine adaptation, if possible, would be along similar but chemical lines -- you'd end up with a non-protein based chemistry, or something not affected by chlorine, or which could buffer it to extreme levels.

Differential resistance to bleach at low concentrations might be possible to breed for. That could be interesting. In a similarly horrifying sort of way.

"The dose makes the poison."

I think at relatively low concentrations, you could set up a similar test.

I agree, but also think one has to consider the mode of action of the poison and the evolution of mechanisms of resistance to it. All poisons are not equal. Sure, generating some level of bleach tolerance is possible--studies using it as a model for oxidative stress have been published in the scientific literature, but i really think that 'meaningful resistance' as observed in the videos would take a long time.

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