It's still absolutely the case... it's just that the fitness function has changed. Now evolution isn't testing to see who can outrun a wooly mammoth or sabre-tooth tiger, or survive without food for 27 straight days, or to see who has the strongest immune system. Now it's testing to see who can navigate their way through high-school, get into a good college, choose a valuable major, get a degree, and get a job making beau-coup money. Since it is still the case that those with more money (on average) have more reproductive opportunities, get better medical care, live longer, etc.
All of that said, let's not ignore that the physical stuff still matters as well. Unless a lot has changed in the 20 some odd years since I was in high-school, the jocks on the football team are still getting laid more than most guys. And being bigger and stronger and more physically fit is still correlated with success in the worlds of business and politics. I don't have the reference handy, but I'm pretty sure I've seen studies showing that taller men are more likely to be elected in political races. And having political power, again, tends to lead to more reproductive success, etc.
To be clear: do rich and successful people have more children than poor ones? Someone has any source on that?
Two thoughts on that:
1. They almost certainly have more opportunity for mating. But they may not always take advantage of that opportunity (especially since they may have child-less sex through various birth control measures)
2. It isn't just a question of the number of children, it's also a question of the fitness of their children. If "fit attracts fit" then the most fit females tend to pair up with the most fit males, and their children average out as more fit than others.
But now we're back to the idea that we no longer know exactly what "fit" means in this world. I guess the answer is "it's complicated". But I still don't see any reason in any of that, to think that no evolution occurs.
But I still don't think that any of that would lead one to think that "evolution has stopped". Even if you step back to only focus on what you describe as "the lower educated, lower income" people, there's still competition for reproductive success within that group. If nothing else, sexual selection is still a factor, even if survival selection isn't as much a factor.
Another thing to consider is the "red queen" theory that human evolution and the evolution of pathogens are locked into a (more or less) permanent "arms race". I don't know that anybody knows for sure that that theory is true, but if it has merit, that's another reason to believe that we are still evolving on some level.
The alternative is to actively promote reproduction of the successful... which sounds, quite rightly, like eugenics. It's a nasty paradox.
[1] https://www.youtube.com/watch?v=d43gKl9xIME [2] https://en.wikipedia.org/wiki/Quiverfull
That may be, but evolution doesn't answer to our conscious desires and ideas of social good or progress. It really is just "the blind watchmaker". What we evolve into isn't "good" or "bad", it just "is". Or at least that's the way I look at it.
What we are currently selecting for is people who have lots of kids and let society pay for their upbringing.
That's nice. Financially secure people tend to have way less children then the working class/poor. Remember, viable offspring is that which lives long enough to reproduce.
That's a fair point, but then we also have to ask "do they have fitter children in turn"? Sexual selection would suggest that more fit individuals seek out and mate with other more fit individuals, as each tries to maximize the fitness of the vessel carrying their genes. If that's the case, I wonder what the effect of that is, carried over multiple generations. I haven't spent a lot of time thinking about this, and I really don't have an answer, but it's worth pondering.
Remember, viable offspring is that which lives long enough to reproduce.
Just living long enough isn't enough, you also have to be able to attract a mate to reproduce with. I suspect it is the case that in modern times, sexual selection is more of a factor in human evolution than survival selection.
Nonetheless, you guys do make a good point about the wealthy/educated having less children. We humans have complicated things by creating things like birth control and by evolving our thinking minds which (in theory) allow us to override the imperative of our "selfish" genes. :-)
e: i think i meant to say birth control (evolutionarily) negatively affects those with more social power
We should be able to find other species populations that exhibit the same relationship between infant mortality and frequency of birth.
The definition of 'fittest' is not set in stone.
You can't look at a population today and identify which individuals are the fittest in evolutionary terms. It's not possible to state with precision that someone who has e.g. more sex or more children or is taller or richer or poorer or better spoken or more sociopathic is more likely to succeed.
Rather, fitness is something that can only be defined in reverse, because today's population is full of individuals with ancestors who have survived and reproduced, and so on all the way back.
As Neal Stephenson puts it: "Like every other creature on the face of the earth, Godfrey was, by birthright, a stupendous badass, albeit in the somewhat narrow technical sense that he could trace his ancestry back up a long line of slightly less highly evolved stupendous badasses to that first self-replicating gizmo---which, given the number and variety of its descendants, might justifiably be described as the most stupendous badass of all time. Everyone and everything that wasn't a stupendous badass was dead."
We're still evolving, even if it's not in a way that would make us better at surviving in the plains/tundra/forest/jungle anymore. It may make us worse at those things (as a species), but better in our new environment (urban, factories, offices).