December 2001, Graves wrote that the explanation of individual patterns of aging must take into account subtle mechanisms such as extensive chance variations in cell number and connections, in cell fates during differentiation, and in physiological patterns that arise during development.
12.
In 1872, Gulick was the first to propose the theory that the majority of evolutionary changes are the result of chance variation, which has no effect on the survival and reproductive success of a species ( today called " genetic drift " ).
