Prologos said- and individual members of a species are willing participants, coerced to work at it hard through the pleasure of sex with it's vagaries and premature death if the genetic "hand of cards" you are dealt is not full of aces.
I'm not picking on Prologos, but that kind of thinking limits one's ability to understand evolution.
For one, the whole "survival of the fittest" meme is a pet-peeve of mine, since you CONSTANTLY encounter it in media presentations for the lay public.
The problem is it's a VAST OVERSIMPLIFICATION, where a more-general principle that is more accurate would be, "Survival of those who survive (and thus pass on their genes to offspring)".
Yes, it's somewhat circular logic, but it's how evolution actually works: "survival of the fittest" is true in SOME, but not all cases, eg a member of an antelope species may be the fastest one who's best-adapted to it's environment, but it STILL can be eliminated from the gene pool if it should be caught off-guard by a lion. Nature doesn't afford animals the luxury of lining up all antelope species at a start line, firing a starter pistol, and then releasing the lions from behind a gate, and the slowest one loses after the fastest lion is allowed to eat it's victim; after repeated trials, only the fastest antelope remains standing and the fastest lions are fed, and each mates with females to pass on their genes in celebration of their victory. That's not how natural selection works, since it operates on probabilities, and is thus a bit-more "messy".
That leads to the subject of who tends to survive: that's variable and messy, and depends on the strength of 'selection pressure(s)' (selection barrier(s)).
If we're going to use cards as an analogy (and I hate analogies, but....), it's not so much about being dealt a 'winning hand of cards' (eg royal flush), as much as NOT being dealt a LOSING hand, which was determined BEFORE the cards were dealt. In the card analogy, a royal flush might be the ONLY losing hand, and everyone else gets to stay in the game for the next round.
In biology, a 'losing hand' might be a deleterious and lethal mutation of genes that resulted in miscarriage of the fetus. But if an individual survives to reproductive age, it's as if their winning that generational 'round' means their genes get to stay in the game, based on their prior ancestor's having passed their tests. THAT'S where the accumulation effect comes into play.
So that's why I say it's not about holding a WINNING hand, as much as not being dealt a rare LOSING hand. Some mutations ARE a burden on the organism by placing it under some physiological load, but as long as they're able to survive anyway, it's not a problem (eg in eyes, some carry genes that make them near-sighted: it's not a problem nowadays, since humans have developed eyeglasses. Hwoever, that same trait meant a significant disadvantage to the individual eg if they couldn't see a predator coming over the horizon while it was in the distance. They may have needed to rely on those in the clan who had the ability to see in the distance, and had to rely on social relationships to survive).
All the card analogies break down since as the fetus example shows, the card game is constantly going on, with each individual in their own private game against their environment. In humans, the "shuffling of cards" and the "dealing" occurs at the moment the zygote forms, and the great benefit of sexual reproduction vs asexual reproduction is how the process avoids the harmful effect of some mutation occurring in the gene pool, ESPECIALLY if different genes are introduced into the gene pool.
I think of a Caucasian kid in Junior High who had a crush on an Asian girl, and who said that their kids would be healthier due to the blending of genes. When it comes to genetic diseases that result from mating between members of the same gene pool, he was absolutely correct, since there are some conditions which are more likely to result when people from the same gene pool reproduce (and why it's a REALLY BAD IDEA to mate with one's siblings: there's a much-greater incidence of defective genes being present in siblings, and some conditions require BOTH sets be present in the child in order for the defect to be expressed). That's why we speak of those who may carry a certain genetic defect, but not be effected (sickle-cell anemia, Tay-Sachs, etc); if carriers reproduce, their offspring may actually not only be carriers, but suffer from the condition.
The fact is the Hebrew preference for not marrying foreigners from the OT has resulted in a higher incidence of eg certain types of breast cancer in Jews.
It's also why the concept of a master Aryan race is flawed, too: it potentially contributes to the accumulation of defective genes which are more likely to be expressed.
Prologos said- I believe though, that we are DRIVEN to evolve, adapt.
Biologists avoid words like 'driven', since there is no outside intelligence driving the process.
Arguably you might say that the intelligence of humans who understand evolution is now exerting an effect on what used to be a mysterious process, and in that light, humans are somewhat driving the process, since every doctor who prescribes a medicine to help someone survive is in a small way effecting the gene pool. In other words, we're artifically influencing evolution, just like a dog breeder does to select for certain traits.