Evolution is a change in the genetics of a population. Some varieties of genes (alleles) get more common and other genes get less common over time. It generally happens due to one random process—mutation—and one non-random process—natural selection.
A lot of people think we get mutations because we need them or want them. That’s not how it works.
Let’s say that a new virus (virus X) emerged and it was deadly. Some people might be more resistant to it just because of the genes they already have. They were just lucky to have genes that gave them an immune system that can fight virus X effectively. Those people would leave more kids than people who died young from virus X. Over time, more people in the population would have the gene that helps fight virus X. That’s evolution.
What if nobody could fight off virus X? Sad story. Only people who avoided virus X would survive. There would be no magical mutation arriving just because we needed it.
We also don’t lose things just because we don’t need them. Wisdom teeth don’t do modern humans much good if they have access to decent dental care. They aren’t going to go away though. They don’t kill people or make them less likely to have kids, so there’s no selection against them.
Even though mutation is random, you can still dream. What mutation do you think would help humans the most?