Stephane Leduc and the vital exception in the Life Sciences

TL;DR

This paper reviews Stephane Leduc's physical approach to embryogenesis, emphasizing the role of mechanical forces and self-organization, and argues its renewed relevance in modern developmental biology.

Contribution

It highlights the historical significance of Leduc's physics-based perspective and advocates for integrating physical principles into current embryogenesis research.

Findings

Leduc's experiments used osmosis and diffusion to mimic biological shapes.

His ideas influenced later thinkers like D'Arcy Thompson.

Modern developmental biology increasingly adopts physics and self-organization theories.

Abstract

Embryogenesis, the process by which an organism forms and develops, has long been and still is a major field of investigation in the natural sciences. By which means, which forces, are embryonic cells and tissues assembled, deformed, and eventually organized into an animal? Because embryogenesis deeply questions our understanding of the mechanisms of life, it has motivated many scientific theories and philosophies over the course of history. While genetics now seems to have emerged as a natural background to study embryogenesis, it was intuited long ago that it should also rely on mechanical forces and on the physical properties of cells and tissues. In the early 20th century, Stephane Leduc proposed that biology was merely a subset of fluid physics, and argued that biology should focus on how forces act on living matter. Rejecting vitalism and life-specific approaches, he designed naive experiments based on osmosis and diffusion to mimic shapes and phenomena found in living systems, in order to identify physical mechanisms that could support the development of the embryo. While Leduc's ideas then had some impact in the field, notably on later acclaimed D'Arcy Thompson, they fell into oblivion during the later 20th century. In this article I give an overview of Stephane Leduc's physical approach to life, and show that the paradigm that he introduced, although long forsaken, becomes more and more topical today, as developmental biology increasingly turns to physics and self-organization theories to study the mechanisms of embryogenesis. His story, I suggest, bears witness to our reluctance to abandon life-specific approaches in biology.