Biomineralization: From the Lab Bench to Paleoenvironments

The ability of organisms to produce calcium carbonate skeletons has independently evolved multiple times over Earth history, in both single-cell and multicellular organisms. These biominerals record many key parameters of the environment where they grow, and thus constitute an invaluable archive. However, biocalcifiers also exert physiological controls over calcification, which leads to uncertainties in both how they respond to environmental change and how they record paleoenvironments in their geochemistry. Biomineralization processes are difficult to observe directly, so much of our understanding of these mechanisms relies on the study of model inorganic experiments, theoretical calculations, detailed consideration of geochemical patterns between and within biominerals grown in controlled culture experiments or collected from the natural environment, and analyses of the biomolecular constituents of biominerals. Together, these results have provided precious and critical information about the formation processes of carbonate biominerals and their ability to respond to, and record, environmental change.

While existing studies have offered important insight into mechanisms of carbonate biomineralization across a range of organisms, key questions remain which complicate our ability to accurately interpret biomineral geochemistry as paleoenvironmental archives and anticipate how they will respond to future changes such as ocean acidification. How comprehensive is our understanding of the inorganic processes governing carbonate mineral growth? Can we predict geochemistry of biogenic calcium carbonates given a known set of seawater boundary conditions? To what extent is calcification controlled by the environment in which the organism grows compared to the physiology and biology of the organism? This Research Topic aims to cover a broad range of cutting-edge research that furthers our understanding of the variety of calcification mechanisms employed by biomineral carbonates, and their implications for paleoenvironmental reconstructions and ocean change.

The scope of the current Research Topic is to canvas promising, diverse and novel research trends in the field of carbonate biomineralization, in connection with their implications for our understanding of paleoenvironmental proxies and global change. We welcome contributions that use existing tools, combine diverse approaches or focus on new methods to advance our understanding of biomineral formation, geochemistry and evolution. Areas to be covered in this Research Topic may include, but are not limited to:

• Ocean acidification influence on calcareous ecosystems;
• Comparison between inorganic and biogenic calcium carbonates;
• Controlled growth (culture) experiments;
• New analytical approaches to study biomineral structure and geochemistry;
• Inorganic calcium carbonate precipitation experiments;
• Progress in modeling the biomineralization process;
• Transport of elements from seawater to the site of calcification;
• History of calcium carbonate biomineralization;
• Influence of biomineralization on fossil and geochemical signal preservation;
• Advances in characterising the chemistry at the site of calcification;
• Role of the organic matrix in biomineralization;
• Insight into calcification from proteomics;
• Influence of biomineralization on interpretations of paleoenvironmental proxies.

Photo: Dried brzyozoan, with its lophophore getting out of the zoecium as it feeds on diatoms and cyanobacteria accumulated nearby
Photo credits: Stephan Borensztajn and Caroline Thaler (IPGP, France)