Global radiation in a rare biosphere soil diatom

• Published in: Nature communications Vol. 11; no. 1; p. 2382
• Main Authors: Pinseel, Eveline, Janssens, Steven B, Verleyen, Elie, Vanormelingen, Pieter, Kohler, Tyler J, Biersma, Elisabeth M, Sabbe, Koen, Van de Vijver, Bart, Vyverman, Wim
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 13.05.2020; Nature Publishing Group UK; Nature Portfolio
• Subjects: Bacteria - classification; Bacteria - genetics; Bacteria - growth & development; Biodiversity; Biogeography; Biosphere; Carbon cycle; Colonization; Diatoms - classification; Diatoms - genetics; Diatoms - growth & development; Dispersal; Ecosystem; Eocene; Evolution, Molecular; Geography; Global cooling; Microorganisms; Nutrient cycles; Oligocene; Phylogeny; Pinnularia borealis; Plankton; Radiation; Rare species; Sequence Analysis, DNA; Soil dynamics; Soil investigations; Soil Microbiology; Soils; Speciation; Species diversity; Species Specificity; Terrestrial environments
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-16181-0

Soil micro-organisms drive the global carbon and nutrient cycles that underlie essential ecosystem functions. Yet, we are only beginning to grasp the drivers of terrestrial microbial diversity and biogeography, which presents a substantial barrier to understanding community dynamics and ecosystem functioning. This is especially true for soil protists, which despite their functional significance have received comparatively less interest than their bacterial counterparts. Here, we investigate the diversification of Pinnularia borealis, a rare biosphere soil diatom species complex, using a global sampling of >800 strains. We document unprecedented high levels of species-diversity, reflecting a global radiation since the Eocene/Oligocene global cooling. Our analyses suggest diversification was largely driven by colonization of novel geographic areas and subsequent evolution in isolation. These results illuminate our understanding of how protist diversity, biogeographical patterns, and members of the rare biosphere are generated, and suggest allopatric speciation to be a powerful mechanism for diversification of micro-organisms.