martes, 25 de mayo de 2010
Chapter 2 - Variation Under Nature
In chapter 2 of the Origin, Darwin begins discussing the kind of variation naturally found in individuals which then lead to new sub-species and new species. A big portion of the chapter is centered around the distinction between a species and a variation, which have no clear definitions, he says. This is still true now, 150 years after the publication of the Origin. In it, he describes that distinction that he found on between bird species and variations on the Galapagos as "vague and arbitrary."
The issue arose again recently when trying to classify the new humanoid remains found in South Africa recently. With a reconstructed skull made from excavated fragments, it has been determined that the bones belong to a new Homo species, the oldest yet discovered. This brings new doubts as to the true "missing link," pushing aside the previous ancestral connection between humans and Australopithecus. The questions remain, however. With the lack of genetic evidence and lack of complete skull, what distinguishes this species from the previous known species, such as previously oldest Homo habilis? What determines that this species still belongs to the Homo genus?