The part about sharks brought me to another reflection:
you seem to see evolution as a "game" oriented to favour exclusively DNA changes that serve gaining advantage in fight for survival.
If it was so, how come we have species like peacocks for example, where males are dragging their absurdly large fan of feathers around, that serves no other purpose then make "impression" on female birds.
I can't see any evolutionary advantage there - on the contrary, partner selection criteria of females seem to lead to choosing male birds that are more "handicapped" in their survival chances because of overgrown feathers that seem to have no other purpose then being superficial ornament and are a burden otherwise.
well, the thing here is, if no female is impressed enough to let him mate with her, his genes will not survive and his information is lost forever. So whatever is required for him to get a mate to choose him, has highest priority right after staying alive for long enough to be able to mate. There could be some less "civil" solutions but it seems that none of those offered a better survival chance. The male doesn't have to survive for longer than he can mate with a female or is of other use for her and his offspring - if he doesn't provide such services, his further existence is irrelevant and he is obsolete. Really harsh, but nature is that way - just look at the praying mantis, after copulation he will be used as a food source by the female - she starts eating him already during mating.
And yes evolution is a survival game - with cooperative and non-cooperative solutions - both are studied in game theory - so it the end it is a game.
Just to add this - any found solution just has to work, it does not have to make sense - whatever works and offers a good enough survival chance will be used, regardless how ridiculous it might be, it just has to work well enough to fulfill the job of survival - that is all what counts. And it is survival of the information, not about survival of the individual.
Richard Dawkins often mentioned a nerve which goes from the brain all the way down the neck of a giraffe just to turn there and get back up to the brain just a bit away from where it started. He is of the opinion that this is a flaw - but who knows, what it provides is "delay" - instead of the signal travelling fast just a short distance it is travelling a longer time before it is reaching it's destination - eventually this delay is useful for something, like short term memory, because the delayed information is an information about the past - even it was just a very short time ago, it could function as short term memory of a signal.
It is sometimes quite hard to tell what something is good for, because we compare it with engineered solutions, whereas this is evolved "technology" and it's purpose might not be that obvious and sometimes even appear to be ridiculous.