Overmuch is claimed for Charles Darwin's Origin of Species,1, ranging from the inaccurate claim that the book was sold out on the day of its publication2 to the more montrous one that Darwin demonstrated the evolution was a fact by the massive evidence he had collected in the book. The truth is that, while Darwin's book did cause a great deal of excitement,3 Darwin provided almost no actual evidence to demonstrate that evolution had occurred. In fact he could not, not with the state of biological sciences at the time. What he did was to provide a very clear and powerful vision of what could make evolution happen, and he garnered a vast volume of this and that of what was already known to induce a deep sense of believability that it just might have happened the way he suggested. Had he demonstrated that evolution had happened and happened the way he suggested, his work would not fall into eclipse within two decades of Origin's publication, as the weight of scientific evidence began to pile up against it. The vision he provided, however, changed the mind of most scientists afterwards (especially when was actively promoted by up-and-coming men like Thomas Huxley, who saw Darwin as an open door to climb the ladder of reputation in the sciences) and made the idea of evolution chic and worth exploring. Darwinism per se found a new lease of life only after the 1930s, when it was resurrected in the form we now know as Neodarwinism (which we shall consider in a later lecture).
The first problem with Darwin's work is that it is more often quoted than it is read. Darwinist fans, of whom I was a 'badge-carrying' member4, harbour this fallacious thinking the the great man is too prestigious to disagree with. Let us begin then by looking at what it was, really, that Darwin said in his book.
The book, in its first edition, is divided into
As a summary of Darwin's theory we may say that it rested on three pillars:
1. The principle of universal common descent - i.e., all living things have descended from a single common ancestor that existed somewhere in the distant past.
To be fair to Darwin, this was not precisely what he said in Origin; what he did say was this:
I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number."
Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. But analogy may be a deceitful guide. Nevertheless all living things have much in common . . . Therefore I should infer from analogy that probably all the organic beings which have one primodial form, into which life was first breathed.5
When everything is taken into due consideration, however, Darwin's theory would not have worked except if there was a single common ancestor, and that is the way his theory has come to be understood.
2. The principle of perpetual and gradual modification - .
3. The principle of natural selection.
By the very nature of his times, of the state of scientific knowledge and resources available at that time, Darwin could not have provided a plausible theory of evolution. There are two main problems why this is so.
First, the fossil record were simply inadequate to provide credible support for his theory.
Second, the science of inheritance—what we now know as 'genetic'—was not yet born. Darwin could not explain adequately how variations could be passed on from one generation to another, and his own explanation actually was fatal to his own theory.
". . . the chief cause of our natural unwillingness to admit that one species has given birth to other and distinct species, is that we are always slow in admitting any great change of which we do not see the intermediate steps. . . . The mind cannot . . . add up and perceive the full effects of many slight variations, accumulated during an almost infinite number of generations. . . A few naturalists, endowed with much flexibility of mind, and who have already begun to doubt on the immutability of species, may be influenced by this volume; but I look with confidence to the future, to young and rising naturalists, who will be able to view both sides of the question with impartiality. Whoever is led to believe that species are mutable will do good service by conscientiously expressing his conviction; for only thus can the load of prejudice by which this subject is overwhelmed be removed." p.481.