ABSTRACT
Human adaptation to environment is complex trait. Given close connection of circadian rhythms with environment, it is quite evident to suppose that adaptation played a significant role in its evolution. Mechanisms implied in diversity of human clock genes are still unclear. Limited works lead to inconsistent outcomes, supporting either a role of spatial variable positive selection or effects of gene flow or both combined phenomena. Our paper represents arguments for the second hypothesis.
Disclosure statement
No potential conflict of interest was reported by the author(s).