Protists as Model Ecological and Evolutionary Study Systems: Emerging Methodologies of the 21st century

Emerging technologies are opening new avenues for the study of past and present marine ecosystems. Shell-bearing protists, i.e., unicellular eukaryotes that form preservable skeletal structures of calcite or silica, are used as a major component of such studies. They occur in large quantities in all oceanic settings, and their excellent preservation potential makes them an ideal resource for ecological studies both in the present and in deep time. 

Since protists are an integral basal part of the global food network and carbon cycle, predicting their response to projected future climate change is essential for modeling ecosystem dynamics in a changing world, and a detailed understanding of protist ecology and evolution is a prerequisite for these predictions. Quantifying the relationships between these organisms and their environment provides new insights into the processes driving adaptation and extinction as a response to environmental change. Emerging technologies increase the quantity and quality of information that can be extracted from living and fossil protists, enabling far more detailed studies than have ever been possible before. These new tools span imaging technologies (e.g., digital microscopy, computer tomography-scanning), genetic analyses (e.g., genomics, high-throughput screening), advanced geochemical analytical methods (e.g., laser ablation, nanoSIMS), ecological and evolutionary modeling, and statistical analyses. The combined results allow quantification of the natural variability from the cellular level to the ecosystem level with unprecedented resolution, creating the most complete picture of protist ecology and evolution to date.

The aim of this Research Topic is to illustrate the breadth of methodological innovation currently available and to provide key examples of the utility of these state-of-the-art methodologies used to study living and fossil marine protists. We welcome contributions on all aspects of applications of new technology for the study of all protist groups, such as:

• Contemporary molecular biology applications, incl. environmental and ancient DNA workflows
• Advanced geochemical analyses on protist shells
• Newly developed protist culturing systems allowing laboratory observations
• State-of-the-art imaging techniques and their application for e.g., taxonomy, species diversity, and ontogenetic studies
• Novel ecological and evolutionary modeling approaches
• Novel applications of statistical methods
• Databases and their applications