During this time, it was widely believed that during the process of fertilization, the alleles of the parents would combine and create a middle-ground zygote, who would become a physical manifestation of the fusion. This was known as “blending inheritance.” Peter Vorzimmer writes in his essay, “Charles Darwin and Blending Inheritance,” “By the time the study of hereditary phenomena became a scientific discipline…blending inheritance had become accepted as axiomatic…In fact, it was, to many nineteenth-century naturalists, the rule” (4). Blending inheritance was accepted as a truth by 19th century society, thus, making it a scientific fact of that time. Fortunately, as society learned more about the process of genetic inheritance, the farcicality of this theory was plain to …show more content…
This is mainly due to the fact that during the time it was being invalidated, Charles Darwin published his theory of evolution. Darwin claimed that evolution was made possible through adaptation by natural selection. From there, he created his three Necessary and Sufficient conditions: there must be variation in a trait within a population, the variation must be heritable, and the variation must influence the fitness of the population. Darwin’s postulates were chiefly evident in the finches of the Galapagos Islands, which was where modern-day anthropologists, Peter and Rosemary Grant, extensively focused their study of Darwinian evolution. The results collected by the Grants were startling. During the year 1977, the Galapagos Islands suffered through a period of extreme drought. This caused the seeds to become large and hard. Due to the change in the type of food available, large-beaked finches were able to exploit these newly enlarged seeds, whereas small-beaked finches were unable to do so, and many died off. However, six years later, in 1983, the island was struck by El Nino. This extended down-pour caused the seeds to soften and shrink in size. In contrast to the effect of the drought, the small-beaked finches thrived on the smaller seeds, whereas the large-beaked finches were not adapted to acquiring such miniscule seeds, and died off. This drastic change in weather and food availability is