Karl Pearson, William Bateson and the homotyposis controversy

Abstract

This paper aims to elucidate both the scientific and extra-scientific factors which contributed to the discussion that took place in Great Britain from 1901 to 1902 between the naturalist William Bateson (1861-1926) and Karl Pearson (1856-1936), the mathematician and statistician: the homotyposis controversy. This will be done both through the analysis of their original publications and their unpublished correspondence. Pearson considered that each organism produces several copies of parts (organs) which are not differentiated, such as blood-corpuscles, scales or spermatozoa, for instance. He called them “homotypes”. According to him, heredity could be regarded as a special case of the production of these organs which he called “homotyposis”. Besides that, Perason rejected Bateson’s claims concerningthe relevance of discontinuous variation to the evolutionary process. The present analysis led to the conclusion that several scientific factors that were present in this debate would also appear later in the Mendelian-Biometrician debate. Besides that, it was possible to identify some extra-scientific factors, such as the struggle for authority in the field of heredity and evolution.