Be the first to like this
The argument between the biometrical school and the Mendelians is one of the most often-cited debates on the structure of evolutionary theory in the years immediately following Darwin's death in 1882. The disagreement between the two parties manifested itself in many forms, and cannot strictly be said even to be about Mendelian genetics – thebattle lines had been clearly drawn as early as 1893, seven years before the “rediscovery” of Mendel's work. The central argument is frequently described as a dispute over the proper interpretation of evolutionary theory – particularly as a debate between saltationists and gradualists. Another view (that of the social constructivists) sees the key issue to be Karl Pearson and Francis Galton’s focus on eugenics. However, a string of acrimonious correspondence published in Nature in 1895 and 1896, I argue, doesn't fit either of these simple molds. In this paper, I argue that we can only make sense of this correspondence if we see the Batesonians (the best name, I think, for the proto-Mendelians) as reacting against the philosophical content of the biometricians' work – particularly, the influence of Machian phenomenalism on Karl Pearson, and W.F.R. Weldon's views on causation. It is this philosophical context, rather than either the rate of evolutionary change or the impact of eugenics, that enables us best to understand the way the parties to the debate understood what was at stake.