Epigenetic Landscapes

Epigenetic Landscapes

Susan Merrill Squier

This book project focused on the iconic image of the epigenetic landscape, introduced by CH Waddington in 1952 to illustrate the probabilistic relationship between genotype and phenotype that constituted the contribution of the new field of epigenetics. The epigenetic landscape is an exaggerated comparison or metaphor—Scott Gilbert has called it “[o]ne of Waddington’s central conceits.” The image uses a landscape in space to represent “divergent developmental paths (chreodes) that a cell might take upon finding itself in different conditions” (Gilbert 2000). While this phrasing is focused on the cell, the scalar implications of the epigenetic landscape extend from the cell to the population, and from the spatially and temporally condensed to the spatially and temporally dispersed. Its metaphoric resonances, which unfold in big space and slow time, reflect an alternative understanding of the relations between human beings, living things, and the abiotic world.

In short, this book studied the epigenetic landscape as what might be called an epistemological space, where hypotheses can be laid out and worked through visually. Although, as Linda Van Speybroek has pointed out, epigenetics has been reduced in contemporary biomedicine to a set of mathematical models, the image of the epigenetic landscape retains the broader epistemological commitments that characterized the field of epigenetics at its inception: its specific formulations of what can count as knowledge, evidence, and proof, its approaches to change and probability, as well as its particular objects of study and modes of observation. The status of the epistemological landscape as metaphor is significant because nonlinear relations can be expressed in a fashion far less constrained in works of art, which provide room for ambiguity. Thus, the epigenetic landscape provides scholars with the epistemological strategies required to reincorporate the broader concept of contingent developmental systems that was written out of theoretical biology as the modern evolutionary synthesis constrained the practice of scientific observation.