Crystals: animal, vegetable or mineral?

Abstract

The morphologies of biological materials, from body shapes to membranes within cells, are typically curvaceous and flexible, in contrast to the angular, facetted shapes of inorganic matter. An alternative dichotomy has it that biomolecules typically assemble into aperiodic structures in vivo, in contrast to inorganic crystals. This paper explores the evolution of our understanding of structures across the spectrum of materials, from living to inanimate, driven by those naive beliefs, with particular focus on the development of crystallography in materials science and biology. The idea that there is a clear distinction between these two classes of matter has waxed and waned in popularity through past centuries. Our current understanding, driven largely by detailed exploration of biomolecular structures at the sub-cellular level initiated by Bernal and Astbury in the 1930s, and more recent explorations of sterile soft matter, makes it clear that this is a false dichotomy. For example, liquid crystals and other soft materials are common to both living and inanimate materials. The older picture of disjoint universes of forms is better understood as a continuum of forms, with significant overlap and common features unifying biological and inorganic matter. In addition to the philosophical relevance of this perspective, there are important ramifications for science. For example, the debates surrounding extra-terrestrial life, the oldest terrestrial fossils and consequent dating of the emergence of life on the Earth rests to some degree on prejudices inferred from the supposed dichotomy between life-forms and the rest.

Two sides of the coin. Part 1. Lipid and surfactant self-assembly revisited

“…They can be expected to occur in biology also as supra aggregates, nanocubic phases surrounded and protected by layers of lamellar [5,6,[62][63][64][65][66][67][68][69][70].…”

Influence of Pyruvic Acid and UV Radiation on the Morphology of Silica-carbonate Crystalline Biomorphs

“…"Worm-like", cardioid sheets and helical fossilized microstructures, among others, are thought to be the indicium of ancient type of cyanobacterial microorganisms from the Precambrian age [1,2]. The origin of life has been dated considering that these morphologies can be constructed solely by living organisms [3,4]. As it is well known, living organisms are able to fabricate biogenic minerals usually in the presence of biomolecules [5,6]; however, it has been demonstrated that complex crystalline long-range symmetry structures with similar morphologies can be synthetized under purely inorganic reactions by inducing the precipitation of carbonates or silica-carbonates in an alkaline medium [7][8][9], which resembles atmospheric conditions in an early stage of the Earth's life.…”

Introduction for bioinspiration

“…In an article with the intriguing title ‘Crystals: animal, vegetable or mineral?’, Hyde [ 3 ] explores the evolution of our understanding of biomolecules that can assemble into aperiodic structures in vivo , so enabling us to understand structures across a wide spectrum of materials, from living to inanimate, with particular focus on the development of crystallography in materials science and biology.…”