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Comment by fivethree | Hacker News Reader

This is sort of a misunderstanding of evolution. It's not building to the most efficient or the greatest form of anything. It's spontaneous change that may or may not survive with no real reference to "the best."

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Your comment reminds me of this discussion I had before here on HN and someone made a reply that has stuck with me to this day in its eloquence. I'll quote it here because I want to share what comment I'm talking about but out of context I think it makes little sense and I think you should read the thread [1]–it's very relevant to what we're talking about here.

> Essentially it is trying to say that we are at a global maximum in a space that is probably more nonlinear. In fact our genes may well be suboptimal in some respects even if you think they have "control".

[1] https://news.ycombinator.com/item?id=4906810, just read the first four comments from the top, mvleming -> mcherm -> mvleming -> justincormack

This also seems to misunderstand evolution. You can think of evolution as a hill climbing optimization algorithm, with a complicated and constantly changing fitness metric. While it is true that any given change is random, and even 'good' changes still only succeed with some probability, over a long time period we see a series of incremental improvements. If there is an opportunity to increase efficiency it is likely that evolution would have found it, given how long the process has been running. Of course, this become less likely when we are discussing new features (the thumb is less optimized than DNA because it is so recent), and as the benefit of these optimizations becomes less. They also become less likely if their are fewer evolutionary paths that might lead to them.

I think the issue here was assuming that the optimization is the best possible one. It doesn't have to be, it just needs to be good enough to still function given past and present evolutionary pressure.

No. You're equating evolution with adaptation, and also making assumptions about beneficial mutations occurring as and when needed.

No, he got it exactly right. Evolution is not an algorithm, it doesn't optimize anything, changes are not improvements, it doesn't seek opportunities to improve efficiency.

That's not how it works. There's no single "global optimum" that lifeforms are evolving towards; there's no final hilltop; there's no intent. This notion of "Evolutionary Teleology" is how we get things like X-Men (which I enjoy for the record, it's not like X-Men is taught in biology class). If there were some global optimum, we'd all have eyesight like Legolas and the color-pallete of a Mantis-Shrimp, instead of a blind spot in the center of our retina.

Evolution just happens, and it is what it is. E.g. Natural Selection didn't "optimize" giraffes so they could reach leaves. Natural Selection is simply a way of explaining that some giraffes had long necks, some had short, and the shorter just happened to die out. Similarly, NBA players didn't "evolve" to play basketball. Some people are tall, and some are short, and the short people just didn't make the cut. "Select" != "Optimize". Evolution is better thought of as a historical accident. We're talking monkeys on a flying rock.

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