Biology and Physics

TL;DR

This paper redefines biology as a distinct science of living matter, emphasizing its unique physical properties and organizational features at various scales, contrasting it with traditional biophysics and hierarchical reductionist theories.

Contribution

It introduces a 'forms of matter' perspective for biological physics, emphasizing the unique physical and organizational features of living matter across different biological scales.

Findings

Living matter at the cellular level is nonunitary and uniquely organized.

Multicellular living systems exhibit shared, analogous, and unique physical processes.

The 'forms of matter' perspective challenges hierarchical reductionism in biological physics.

Abstract

This article frames the relation between biology and physics by characterizing the former as a subdiscipline rather than a special case of the latter. To do this, we posit biological physics as the science of living matter in contrast to classic biophysics, the study of organismal properties by physical techniques. At the scale of the individual cell, living matter is nonunitary, i.e., not composed of aggregated subunits, and has features (e.g., intracellular organizational arrangements and biomolecular condensates) that are unlike any materials of the nonliving world. In transiently or constitutively multicellular forms (social microorganisms, animals, plants), living matter sustains physical processes that are generic (shared with nonliving matter, e.g., subunit communication by molecular diffusion in cellular slime molds), biogeneric (analogous to nonliving matter but realized through cellular activities, e.g., subunit demixing in animal embryos) or nongeneric (pertaining to sui generis materials, e.g., budding of active solids in plants). This "forms of matter" perspective is philosophically situated in the dialectical materialism of Engels and Hessen and the multilevel physicalism of Neurath and the logical empiricists. We counterpose this view to informationism and to genetic and other hierarchically reductionist physical theories of biological systems and highlight open questions regarding incompletely characterized and enigmatic forms of living matter.