>How does this explain different phenotypes in grouped populations?
Random fixation and/or founder effect, among a myriad of effects that don't involve natural selection.
>Let's say for instance that a species of ant is known to be more aggressive, why it was that way is probably generic drift. Why it stays that way is because of its environment, and it is selected for.
Or the different alleles for aggressiveness (whatever that means, and assuming they exist) got fixed due to drift? Who knows. The burden of proof is on the adaptationist to show that something other than contingency happened.
No one is saying evolution is all random, only mostly random. Natural selection obviously plays a role in shaping the direction of individual mutations - deleterious ones get purged relatively quickly. When those are culled, the vast majority of mutations are neutral or nearly neutral.
>Brute forcing the genome to something better is clearly possible, but if you converted all of the matter in the visible universe into DNA and mutated every strand a trillion times a second for a trillion years, it's very possible you would never even encounter a viable strand of DNA for that organism.
Yes, but consider the following. I just ran:
>>> np.random.random()
0.8867453976799686
What were the odds that I ended with this specific 18-digit float in the whole set of floats in [0.0, 1.0)? And yet, here we are.
The word you're looking for is contingency. Gould spoke much about "replaying life's tape" and how it would yield different results every time it was "replayed". Interestingly, people have actually attempted to put this thought experiment into practice at a very prosaic level [0] [1]. They find that although there are convergent patterns of adaptation, over the long term populations diverge considerably.
Here's a handy tip you won't find often on HN: any time you're wondering whether X is "an evolutionary adaptation", where X is "any complex phenotype that isn't a genetic disease", the answer is very probably no. Most of our evolution is accidental, because the dominant evolutionary process is genetic drift [0]. There are exceptions to this rule but they have been usually very easy to demonstrate - natural selection, when it occurs, is fairly obvious to see. There's no such thing as a hidden force that invisibly yet tangibly acts on all genes in such a subtle manner that you can't ever detect it through a reliable genetic mechanism - that's just 21th century essentialism.
Means testing is stupid and the bureaucracy involved to check whether the free lunch does not go to the undeserving (god forbid) is often not worth it, compared to just giving everyone something (and recouping it through taxation).
I'm turning your argument around: why go around and invent fake conspiracy theories when actual conspiracies are a thing and are nothing like the fake ones?