No, we haven't. We've merely changed them, quite significantly. But there's still selection processes ongoing.
Since people tend to hear "Racism!" when this sort of thing gets said, the pressures I'm discussion includes things like being able to survive the civilization's schooling system (teen suicides don't have offspring) and the different ways of attracting and being a good mate than one would pursue in an agrarian or hunter-gather society, such as being a visibly wealthy nerd. There's a lot of things still affecting and shaping civilization through who has how many children with who and how they treat them, and I haven't got a personal list of "good" or "bad" such effects, because it's not really about "good" or "bad", they just are, no matter what labels you put on them.
Another example is the hypothesis that a significant part of why "autism" is on the rise is "assortative mating", or, to put it another way, that there are evolutionary pressures in modern society creating couples who end up essentially breeding for traits that, when overexpressed, may be called "autism". I'm not making a claim that is necessarily true, but it's an example of an evolutionary theory applying in the here & now.
Hence “mostly”. But evolution requires large time-scales to function; selection for arbitrarily-fluctuating criteria is practically no selection at all.
Anyone trying to sell you on selective evolution is either ignorant or has an ulterior motive. There's a reason people tend to hear, "Racism!" when this sort of thing gets said -- it's not based at all in science, so what else would it be based in?
Yes via selective breeding. Look into Landian analysis of urban centers as “IQ shredders”. Cities attract the smartest people and then tank their birth rate.
> we've mostly neutered evolutionary pressures on ourselves. In ten thousand years, this might be a minor problem
It’s going to be a problem much sooner than that. Look into Yudkowsky’s analysis of evolutionary error correction bandwidth.
That's pretty simplified – but even if it wasn't, we're not going to run out of “clever genes” because it's not as simple as that. (But even if it were, the selection isn't strong enough for that to happen.)
> It’s going to be a problem much sooner than that.
If our artificial selection pressures remain the same. Which they won't. Two hundred years ago, our society's “artificial selection” was completely different; in two hundred years, it'll be completely different again.
Your model is busted - the Flynn effect has already reversed and intelligence is decreasing again.
You’re right that it’s “not as simple” as my one-sentence summary but my claim is directionally correct.
> it’ll be completely different again
The risk has nothing to do with what the concrete pressures are, but how much error correction bandwidth we have vs background mutation load rate.
Which metric are we using to measure intelligence this time? How do you know it gives meaningful results for what you're trying to use it to measure? (Please don't say IQ.) And has the study been replicated?
> The risk has nothing to do with what the concrete pressures are, but how much error correction bandwidth we have vs background mutation load rate.
But the selection effects you've described are all local and weak. Worst-case scenario – absolute worst-case scenario – the city Americans marry rural Africans and the problem goes away. But it won't get to that point.
Eliezer Yudkowsky knows a lot about philosophy of thought, and AI theory, but he hasn't put as much effort into learning about genetics. If the average geneticist isn't worried, chances are that he's made a mistake in his reasoning (or that you're misunderstood his concerns) – and I haven't heard anybody in a biological field worrying about this.
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Wait, are you talking about his “in the absence of selection pressure, we'll get mutations that aren't filtered out”? If so… that's a hundreds of generations kind of problem, and I'm confident that stuff like IVF embryo selection (selecting against the genes for known genetic conditions) is already counteracting that effect. (Yes, this is technically eugenics, yes it could get dystopian if we're not careful, no it doesn't justify what the word “eugenics” makes you think of, no I shouldn't feel the need to write this parenthetical, yes this is the internet we're talking about.)
Transposons are likely to be a bigger issue. I read that they've started duplicating themselves more recently, and we don't really know why.
But imagine the human genome (for some unidentified reason that hasn't happened in the last thousand years) starts degrading across the entire world, so we only have a hundred years left before no human fœtuses are viable. We could just GM a human embryo to be the genetic child of modern-day humans (whose genome we've already sequenced), and we roll-back any mysterious genetic problems that far-future humans might develop.
There is an upper bound to how bad things can get, even imagining something out of a sci-fi novel, so I am highly suspicious of the motives of people who get loudly concerned about the “decline of the human genome”.
In fact, we've mostly neutered evolutionary pressures on ourselves. In ten thousand years, this might be a minor problem, but we'll probably have figured out a way of doing genetic modification without being monsters by then.