Thomas Hunt Morgan: Materialism and experimentalism in the development of modern genetics

The reception of Mendelism in the United States, 1900-1930

Scholars have differed on the question of why Mendel's work was neglected between 1865 and 1900, and the (by contrast) relatively rapid acceptance of Mendelism in many countries after 1900. This paper focuses on two factors that have not been well explored in the debate. The first is that Mendelism fit perfectly into the atomistic philosophy associated with mechanistic materialism in western science, and thus was strongly promoted by a younger group of biologists around 1900 to raise the prestige of biology to the rigorous level of the physical sciences. The second factor was that Mendelian theory, with its experimental and predictive qualities, fit well into the new demands for industrialization of agriculture both to feed a growing urban population and to provide an arena for capital expansion. This paper proposes that the early promotion of Mendelian research, by both private and public funds, owed as much to economic and social as to biological causes.

Embracing complexity: organicism for the 21st century

Organicism (materialistic holism) has provided the philosophical underpinnings for embryology since the time of Kant. It had influenced the founders of developmental mechanics, and the importance of organicism to embryology was explicitly recognized by such figures as O. Hertwig, H. Spemann, R. Harrison, A. M. Dalq, J. Needham, and C. H. Waddington. Many of the principles of organicism remain in contemporary developmental biology, but they are rarely defined as such. A combination of genetic reductionism and the adoption of holism by unscientific communities has led to the devaluation of organicism as a fruitful heuristic for research. This essay attempts to define organicism, provide a brief history of its importance to experimental embryology, outline some sociologically based reasons for its decline, and document its value in contemporary developmental biology. Based on principles or organicism, developmental biology should become a science of emerging complexity. However, this does mean that some of us will have to learn calculus.