Summary

As genetics and heredity become recognized as a central component of biology, it had to be reconciled with other existing biological ideas. Genes had to explain the phenomenon of variation as well as evolution. By 1910, it was accepted that genes carried hereditary information on chromosomes and that variations in human traits were "distributed in smooth, continuous, bell-shaped curves" (103). To explain this, a researcher named Fisher concluded that there are multiple genes which govern a single physiological characteristic. In the 1930s, a man named Theodosius Dobzhansky "set out to describe the extent of genetic variation in wild populations" in order to better understand evolution (104). Through experiments on flies, he concluded that a genotype plus an organism's surrounding environment plus external triggers, plus an element of chance all come together to equal a specific variation of phenotype. As Mukherjee explains: "In the...