In 1859 Charles Darwins book On the Origin of Species popularized the notion of biological (and therefore social) evolution. Scholars began to discuss civilization as a unilinear process with races able to ascend or descend a graduated scale. The European was the fittest to survive" [The Aboriginal] was doomed to die out according to a "natural law", like the dodo and the dinosaur. This theory, supported by the facts at hand [i.e. that Aborigines were dying out, which was due to ill-treatment and disease C.W.] continued to be quoted until well into the twentieth century when it was noticed that the dark-skinned race was multiplying. Until that time it could be used to justify neglect and murder.