Reactions to On the Origin of Species which all forms of evolutionism were identified with Darwinism. For a description of Darwin's life, work and influences in the following period see the article: Darwin from Orchids to Variation. Note: this article uses Desmond and Moore, "Darwin", as a general reference. Other references used for specific points or quotations. Reactions to On the Origin of Species The immediate reactions to "On the Origin of Species", the book in which Charles Darwin described evolution by natural selection, included international debate, though the heat of controversy was less than that over earlier works such as "Vestiges of Creation". Darwin monitored the
On the Origin of Species to be separate species produced fertile hybrid offspring freely, and in other cases what were considered to be mere varieties of the same species could only be crossed with difficulty. Darwin concluded: "Finally, then, the facts briefly given in this chapter do not seem to me opposed to, but even rather to support the view, that there is no fundamental distinction between species and varieties." In the sixth edition Darwin inserted a new chapter VII (renumbering the subsequent chapters) to respond to criticisms of earlier editions, including the objection that many features of organisms were not adaptive and could not