One thing that's always bemused me about scifi is future superhumans adapted for ultimate survival (e.g. the Nietzscheans in Andromeda) are tall, muscular, lean, brave, intelligent, etc.
Whereas for survival, you want humans that are small (so they need less food), weak because they have slow metabolisms, hairy to keep the heat in, fat because they are good at storing food in case of famine, cowardly so they avoid risk at any cost, dumb so they just repeat procedures that are known to work, and so on.
You're at least partially confusing individual survivability with group survivability. Absolute cowardice, while beneficial to an individual, is ultimately so problematic for the group that it will result in everyone's death.
Dumbly repeating procedures that are known to work without analysis will not only cause stagnation, but also likely cause industrial and environmental collapse unless a system is so tightly controlled that it is impossible for any procedure to lose effectiveness. And unless technological improvement is impossible, this is clearly a suboptimal survival strategy, as survivability may not be improved.
"Absolute cowardice, while beneficial to an individual"
If this were actually true then evolution would go ahead and make everyone absolutely cowardly. Evolution works because traits that are helpful to an individual become more common; because the individuals with those traits reproduce more. Nothing stops evolution going down paths that are bad for the species.
(Of course, if it gets so bad that the species goes extinct then we simply won't see that species any more. But nothing prevents this from happening.)
It isn't actually true though: risks have their rewards.
You need to spend some more time with evolutionary theory. Populations do indeed evolve along with individuals. You own message explains why; there are selection pressures at the population level as well. See also animals that are always found in communities, like ants or humans. It's not either/or. It never is with evolutionary theory.
"Populations do indeed evolve along with individuals"
Individuals don't evolve at all. Evolution is changes in gene frequency over time.
What I think you're trying to talk about is macroevolution, where species that happen to have certain traits survive longer than other species. Sure, this sort of thing happens. But I was responding to the claim that "absolute cowardice [is] beneficial to an individual" and noting what would happen to the level of cowardice in a population if that were actually true.
What it looks like you're not paying sufficient attention to is that selection happens at the level of the gene, not the level of the individual.
It is absolutely not beneficial to the individual to put energy out to try to have sex, put energy into offspring, or to take risks for others. However all of those behaviors have tended to be beneficial for the genes that the individual has because the others who are helped are likely to have the genes producing that behavior. Therefore all of those behaviors have evolved notwithstanding the fact that they are inconvenient for individuals with those genes.
The truth is that the truth you allude to is only one of many truths, and I consider it my duty as a mansplainer to point out that there are other truths you failed to incorporate into your paragraph in such a way that makes me feel as if I have a bigger and more complete collection of truths because then I won't feel so bad that my pants make me feel ugly.
What you refer to as macroevolutionary effects are equally problematic for a small village. It will quickly be destroyed and any wealth it has taken by a neighboring village whose warriors are not afraid to give their lives in service of their chief.
Last I heard there was still some ongoing debate among ev biologists about whether group selection was an important effect or not; I think the general consensus tends to be that it's a pretty small effect except in certain special cases.
The existence of traits like courage is far better explained by sexual selection. Women throughout history have always strongly preferred courageous men to cowardly ones. This is only partially cancelled out by the fact that courageous men tend to die more often.
As civilization continues to advance, and fewer and fewer people die before childbearing age, I'd expect the balance between sexual selection and survival selection to tip even more strongly in favour of sexual selection, so it's quite likely that (even absent widespread genetic modification) the people of the future will indeed tend to be "sexier" than the people of the present.
(Partially cancelling this out is the idiocracy effect whereby poor dumb folks have more children; I can't estimate which is more powerful.)
>The existence of traits like courage is far better explained by sexual selection. Women throughout history have always strongly preferred courageous men to cowardly ones.
That's not an explanation. Why do women prefer courageous men?
Do you mean to imply that courage is like a Peacock's tail? It doesn't help a man survive, but it signals that he must be really good at surviving in other ways.
Evolution works because traits that are helpful to an individual become more common; because the individuals with those traits reproduce more.
It depends on what you mean by helpful. If you mean helpful in helping them live longer, then it is patently false. Look at peacocks feathers as one famous example.
In any species which require two to reproduce, you also have to be able to attract a mate (generally mostly on the male side), and that may require bravery, willingness to make expensive displays of power, and all kinds of other things that may go against the best way for the individual to survive.
Similarly, in a species that produces few off spring, those members also need to help ensure the off spring survive. This may involve charging into fights you could have run from so your off spring can run, searching for far more food then you need for yourself possibly at great risk, etc. In short again other traits that may go against the individuals personal survival.
You're conflating "beneficial to an individual" and "reproduce more." Reproducing and successfully raising young requires time and energy that an individual could use towards personal survival.
Evolution is a game of balance. On the face of it, a predator being faster and stronger so that it can catch more prey seems like an obvious benefit that would catch on. But the time, energy and resources to do that might draw from what's needed to reproduce and raise young.
No, it does not. To understand why lets compare it to another situation. Cancer cells vs normal cells. Cancer cells are "selfish" so if you wait long enough every cell on earth would become a cancer cell, right?
It isn't about survival. It is about procreation. If you survive to 100 years old and have no kids, you "failed to survive" in an evolutionary sense compared to a guy who died at 30 but has 3 kids.
So if the tall, muscular, lean, brave, intelligent guys can have more kids than the short, fat, hairy guys, those guys will have a greater influence on the future species than the survival in the face of catastrophy.
Short of a disaster that pushes humankind to the brink of extinction, natural selection is likely to be based on traits of people who mate and reproduce. The more likely you are to mate and reproduce, the more likely the traits you have get passed on. It might be a logical leap but perhaps because of this, humans might evolve towards whatever is more attractive to other humans.
Except that humans don't (or will not) need these qualities anymore. Humans will evolve to be desirable to the other sex, i.e. "tall, muscular, lean, brave, intelligent".
Some of Alistair Reynolds' books feature Neotonic Infantry - genetically engineered super-soldiers that look like children. They take up less space, eat less and being forced to kill a small child causes serious psychological damage to the enemy.
Whereas for survival, you want humans that are small (so they need less food), weak because they have slow metabolisms, hairy to keep the heat in, fat because they are good at storing food in case of famine, cowardly so they avoid risk at any cost, dumb so they just repeat procedures that are known to work, and so on.