Theoretical thinking from gene evolution to cell type evolution.

During evolution, mutations occur randomly and are fixed by selection. At the same time, species gradually formed, producing various life forms. In the traditional evolutionary theory system, mutations are considered genetic mutations by default, and somatic mutations are usually applicable in specific scenarios such as carcinogenesis, immunity and aging. At the same time, selection plays a role at multiple levels of living systems, including genes, cells, tissues and organs, individuals, populations, species, and even ecosystems. The research community of modern life science expresses genetic mutations as genotypes and cellular and other level characteristics as phenotypes, and finds that phenotypes are determined by both genotypes and environmental factors. Currently, it is unclear how genotypic and environmental factors act at the cellular level to create and fix new cell types. In this review, we summarize that it's time to move forward from gene evolution to build the framework for cell type evolution and finally update the theoretical system for evolutionary biology.