Well organisms who have traits that are beneficial to them and would make them live long enough to usually reproduce, it would become an adaptive trait. That organism who has that trait will most likely live the longest and reproducing which will pass down their traits. Other same type of organisms who don’t have that trait will most likely die quicker then those who do and they won’t be able to pass on their genes which will lead to the natrual selection being very few of those types. If your born with a non useful trait, you jsut pass it down, you can’t just have the ones that benefit you unless yoru parents have it. This is why at the ”end” there will be more with useful traits and barley any with non.
