What is evolution? (Kerkut)
“There is a theory which states that many living animals can be observed over the course of time to undergo changes so that new species are formed. This can be called the ‘Special Theory of Evolution’ and can be demonstrated in certain cases by experiments. On the other hand there is the theory that all the living forms in the world have arisen from a single source which itself came from an inorganic form. This theory can be called the ‘General Theory of Evolution’ and the evidence that supports it is not sufficiently strong to allow us to consider it as anything more than a working hypothesis. It is not clear whether the changes that bring about speciation are of the same nature as those that brought about the development of new phyla. The answer will be found in future experimental work and not by the dogmatic assertions that the General Theory of Evolution must be correct because there is nothing else that will satisfactorily take its place.”
—Kerkut, G.A. (1927–2004), Implications of Evolution, Pergamon, Oxford, UK, p. 157, 1960 (available online in the Public Domain at ia600409.us.archive.org/23/items/implicationsofev00kerk/implicationsofev00kerk.pdf).