It's not a question. There are a few misconceptions around the concept of natural selection that has always bothered me. I'd like to clarify them :-
- There is no "end goal"."Evolution" is a horribly confusing term. It does not imply a march towards a "goal". It does not need "time" to reach a goal. At any given time for any given environment you'll find species adapted, or evolved, for that environment. As environments change, some mutations will die out while others will survive. That's it.
(Even then, organisms are not necessarily "perfectly adapted". You just have to be better adapted than the one you are competing with)
- You do not 'un-evolve'. There is no such thing as "unevolving". A species can only change to adapt to its current environment. There are places on Earth where due to darkness or muddiness, fish no longer need eyes and they actually lost their eyes. They did not "unevolve". They merely adapted to their environment. They cannot survive in ours and we cannot in theirs. Environments do change and render old adaptations useless or sometimes harmful, but that's not "unevolving".
- "Most evolved" or "highly evolved" does not mean "complex". A hoof (horse's foot) is perfectly evolved for the task it has to perform, even though it's much simpler than feet of many other animals (which are evolved for the task they performed).
- Organisms do not always improveEvolution does not imply that the current state is the best design. Sometimes a less-than-ideal mutation accompanies another mutation that allows you to pass your DNA more successfully. Sometimes environments change. Sometimes you get by with a less than ideal mutation because there wasn't a better one to compete with.
- Better mutations do not always survive. Many species have gone tens of millions of years with relative little change. It's not that they did not have mutations that were better. But current design is probably adapted enough that new mutation did not get a chance to noticeably change the gene pool. Just because an individual has a better mutation it does not necessarily follow that the mutation will change the gene pool.
- Mutations are random. You get a random mutation that may allow you to be more successful in passing your genes. Weather patterns and other changes are also random that disrupt normal eco systems and make new selections and new winners / losers. If you go back 500 million years then we'd have totally different animals.
(I should clarify, that convergence will still happen. There will still be sea creatures that are agile swimmers. Their bodies will be similar to shark's. They may have different type of eyes or different senses altogether or different locations but ultimately, there are only that many ways of being agile swimmers)
- Natural selection is not random. I know I just said mutations are random, but what survives and what doesn't is anything but random.
- However, everything is not due to natural selection - Some changes happen simply due to genetic drift that over time, change species without any "natural selection".
- Evolution is anything but efficient - Male nipples, enough said.
- It's too early to know whether intelligence and body design that leads to technological advancement is a successful adaptation. Humans may well not only go extinct themselves, but cause a massive extinction due to their actions. If so, then at least on our planet this level of intelligence would turn out to be a poor adaptation that got wiped out by natural selection.
- Evolution does not give you what you need. Sometimes well meaning individuals imply that natural selection will give an organism what it "needs". Evolution isn't smart. If a population has a genetic variant that is more successful in reproducing then that variance increases with each generation and changes the gene pool. But that adaptation may never come. It may happen but not survive long enough to change the gene pool. It may be accompanied by another mutation that makes the individual less competitive. And a whole lot of other reasons why organisms may not adapt. If they always did then there wouldn't be natural extinctions.
I hope it clarifies a few things. Some other concrete examples that demonstrate some of my points above: male nipples