 Recent studies suggest that the human germline mutation rate and spectrum evolves rapidly, with variation in generation time playing a role. These studies also found evidence of multiple independent changes that occurred after the split of continental groups, as well as a difference between groups sampled in and outside of Africa in older TC polymorphisms. Additionally, the study showed that the generation time could not fully account for the observed patterns of mutation types. Therefore, other factors such as genetic modifiers or environmental exposure must have played a role in shaping the human mutation landscape. This article was authored by Zeyu Ajao, Yulin Zhong, Nathan Kramer, and others.