In this portrayal, mutationism was defeated by a synthesis of genetics and pure selection that supposedly started later, around 1918, with work by the mathematician Ronald Fisher. However, the alignment of Mendelian genetics and pure choice began as early as 1902 with a paper by Udny Yule, and built up with theoretical and experimental work in Europe and America. Despite the controversy, the early mutationists had by 1918 already accepted natural choice and explained steady variation as the result of multiple genes performing on the identical characteristic, such as height. Point mutations may come up from spontaneous mutations that occur throughout DNA replication. Mutagens could be bodily, corresponding to radiation from UV rays, X-rays or excessive heat, or chemical (molecules that misplace base pairs or disrupt the helical shape of DNA).
This idea of a “center of genetic diversity” is used to establish the center of origin of a bunch … Read More