Most people have heard of evolution. Some accept it, some reject it, but either way, most don’t actually understand it. There is a perception that evolution means that all life will, with enough time, morph into some sort of “higher form”. For example, many people think that eventually humans will evolve to fly or ants will evolve to be monkeys and then humans. However, that is not how evolution works.
For starters, the idea of all “lower lifeforms” evolving into humans is flawed. It implies a sort of vertical hierarchy of taxonomy in which all life is sorted by its perceived superiority to ones below it (often with humans at the top). This is absurd; there is no such thing as one form of life being superior to another. If it were true, then should not birds be higher than humans since they can fly? Should not fish be higher than humans since they can live underwater? The fact is that each creature evolves to do well in its own environment, not reach a theoretical point of perfection.
Another problem with most people’s conception of evolution is that over time, they will become more and more advanced. Evolution is not an intelligent mad-scientist doing genetic experiments. It does not require creatures to become “better and better”; instead it only requires creatures to become good enough to survive long enough to pass on their genes. That is, if a giraffe is able to eat the leaves at the top of the tree to stave off starvation by having a slightly longer neck, then that is sufficient; it need not grow wings. If a fish is able to avoid being eaten by swimming faster, then that is good enough; it does not need to grow legs and take to land. It is like the old saying: I don’t need to run faster than the lion, I only need to run faster than you.
Just like how scientists prefer the term climate change to global warming because it makes it easier to avoid confusion, it is easier for people to avoid confusion by avoiding the term evolution which implies necessary change, and instead use natural selection which makes it more clear what is happening: creatures that are better able to survive can pass on their genes.