'Further Development' of Mendel's legacy? Erich von Tschermak-Seysenegg in the context of Mendelian-biometry controversy, 1901-1906.

The contribution of Erich von Tschermak-Seysenegg (1871-1962) to the beginning of classical genetics is a matter of dispute. The aim of this study is to analyse, based on newly accessible archive materials, the relevance of his positions and theoretical views in a debate between advocates of early Mendelian explanation of heredity and proponents of biometry, which took place in England around 1901-1906. We challenge not only his role of an 'external consultant', which at the time de facto confirmed his status of 'rediscoverer' of Mendel's work but also analyse his ambivalent positions which are to be seen as a part of 'further development' (Weiterführung), a development of Mendel's legacy as he understood it. Second, there is an interesting aspect of establishing connections within an 'experimental culture' along the Mendel's lines of thought that was parallel to the first step of institutionalizing the new discipline of Genetics after 1905/06. Part of the study is also the analysis of contribution of his older brother Armin von Tschermak-Seysenegg (1870-1952) who--much like in the case of 'rediscovery' of 1900-1901--was for his younger brother an important source of theoretical knowledge. In this particular case, it regarded Bateson's 'Defence' of Mendel from 1902.