 The book was successful in its goal of persuading readers of the reality of evolution, effectively illustrating topics such as island biogeography, speciation, and competition.Huxley further showed that the appearance of long-term orthogenetic trends – predictable directions for evolution – in the fossil record were readily explained as allometric growth (since parts are interconnected).All the same, Huxley did not reject orthogenesis out of hand, but maintained a belief in progress all his life, with "Homo sapiens" as the end point, and he had since 1912 been influenced by the vitalist philosopher Henri Bergson, though in public he maintained an atheistic position on evolution.