- Darwin and the first evolutionary synthesis: Its grandeur, constraints, and difficulties
- Genetics and the "black day" of Darwinism
- Population genetics, Fisher's theorem, fitness landscapes, drift, and draft
- Positive and purifying (negative) selection: Classifying the forms of selection
- Modern Synthesis
- Recommended further reading
Genetics and the "black day" of Darwinism
An urban legend tells that Darwin had read Mendel's paper but found it uninspiring (perhaps partly because of his limited command of German). It is difficult to tell how different the history of biology would have been if Darwin had absorbed Mendel's message, which seems so elementary to us. Yet this was not to be.
Perhaps more surprisingly, Mendel himself, although obviously well familiar with the Origin, did not at all put his discovery into a Darwinian context. That vital connection had to await not only the rediscovery of genetics at the brink of the twentieth century, but also the advent of population genetics in the 1920s. The rediscovery of Mendelian inheritance and the birth of genetics should have been a huge boost to Darwinism because, by revealing the discreteness of the determinants of inheritance, these discoveries eliminated the Jenkin nightmare. It is therefore outright paradoxical that the original reaction of most biologists to the discovery of genes was that genetics made Darwin's concept irrelevant, even though no serious scientist would deny the reality of evolution. The main reason genetics was deemed incompatible with Darwinism was that the founders of genetics, particularly Hugo de Vries, the most productive scientist among the three rediscoverers of Mendel laws, viewed mutations of genes as abrupt, saltational hereditary changes that ran counter to Darwinian gradualism. These mutations were considered to be an inalienable feature of Darwinism, in full accord with Origin. Accordingly, de Vries viewed his mutational theory of evolution as "anti-Darwinian." So Darwin's centennial jubilee and the 50th anniversary of the Origin in 1909 were far from triumphant, even as genetic research surged and Wilhelm Johansson introduced the term gene that very year.