I said at the beginning of my paragraph that I get what you're saying. Did you miss that?
no i did see that. after which you proceeded with the agenda that sexual selection is arbitrary and should be considered an influence apart from environment on genetic evolution. you can't say "what you're saying makes sense" then proceed to try and prove that it doesn't, you are completely contradicting yourself
The only difference we have here is in words.
that would only be true if I also believed that sexual selection were arbitrary
Now the reason I don't consider sexual selection to be the same is that it does often work against a species' adaptiveness against predators etc. Check out this famous study of guppies which illustrates this nicely - female guppies select mates with the brightest colours. However, the brighter the guppie, the more conspicuous it is to predators. This study shows the balancing effect of sexual selection vs selection by predators - guppies in streams without predators will be much brighter than those in streams with predators. The females aren't selecting any differently in each stream - rather, the effect of selection by predators is balanced against sexual selection. If your theory was correct, the females would have selected for the dull guppies all along, considering this is what increases the survival of guppies
if the guppies bright colours have backfired and made it more visible to predators, that's unfortunate for them, but it doesn't undermine the notion that sexual selection is based on environmental factors. if a predator gets thrown into the mix and it's bad news for the brighter guppy they'll find a harmonious balance with it or die off, they wouldn't be the first species that didn't make it. the female guppy will still choose the brightest males in the predator stream, they may be comparatively darker than those in the predator-free streams, but their colours are still apparent for a physiological reason which is beneficial to their survival beyond just being sexy, it’s sexy to the female guppy because it instinctively says something to her about him and his genes, it has to
the female isn't going to overcome instinctive attraction to bright males overnight because there is a predator in the water, that could take millions of years. if that is too slow for them to avoid demise on account of predation there's nothing that can be done. it's illogical to assume that they just became bright because the females would find it attractive, there has to be an environmental cause driving their bright colours which the female in turn finds attractive, namely genetic health
if based on what you understand of this famous study of guppies from the 1970's you would like to believe that sexual selection is arbitrary go for your life, but you absolutely have not proven it, and there is no valid reason for me or anyone else to believe that sexual selection is not dictated by environmental requirements, or should be considered a separate influence on genetic evolution