What are some examples of evolution that can be observed during the course of a humans lifespan?

Changes in the frequency of genetic variants, such as lactose tolerance in certain populations, can be observed within a human lifespan. Microevolutionary changes in bacteria and viruses, like antibiotic resistance, can also be observed relatively quickly. Additionally, human-induced environmental changes can drive rapid evolution in species, such as urban-dwelling animals adapting to city environments.