How do human effect natural selection?

if this is about  climate change then here you go If climate change is caused by humans, then no organisms can avoid selection resulting from human actions. ... A well-known example of natural selection in action is the development of antibiotic resistance in microorganisms. Tricky. Humans created the selective force (antibiotics) and applied them to microorganisms

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.