How can natural selection can cause organisms to change over generations.

Natural selection changes how well a species can survive in an environment.

Explanation:

I'm not the best at biology, but natural selection a term we use that's describes nature's way of choosing the strongest to survive. The species with the strongest adaptations will survive while the others will die off. For example, if a school of fish was forced to live in a colder habitat than usual, over many years some fish will adapt to that environment and be able to withstand it. But, some fish won't get those adaptations and be killed off. But, future generations will be born with that ability to withstand the cold environment and it would become normal. So, natural selection changes the way a species lives. Hope this helps