Biosilicification Drives a Decline of Dissolved Si in the Oceans through Geologic Time

Frontiers in Marine Science

卷:4

Alan O. Marron¹  Guillaume Fontorbe²  Christina L. De La Rocha²  Johanna Stadmark²  Patrick J. Frings³  Wim Clymans⁴  Katharine R. Hendry⁵  Daniel J. Conley⁶ 

[1] Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge, United Kingdom;

[2] Department of Geology, Lund University, Lund, Sweden;

[3] Department of Geoscience, Swedish Museum of Natural History, Stockholm, Sweden;

[4] Earthwatch Institute, Oxford, United Kingdom;

[5] School of Earth Sciences, University of Bristol, Bristol, United Kingdom;

[6] Stellenbosch Institute for Advanced Study, Stellenbosch, South Africa;

关键词: silicates;    diatoms;    sponges;    cyanobacteria;    biogeochemical cycles;   

DOI  :  10.3389/fmars.2017.00397

来源: DOAJ

【 摘 要 】

Biosilicification has driven variation in the global Si cycle over geologic time. The evolution of different eukaryotic lineages that convert dissolved Si (DSi) into mineralized structures (higher plants, siliceous sponges, radiolarians, and diatoms) has driven a secular decrease in DSi in the global ocean leading to the low DSi concentrations seen today. Recent studies, however, have questioned the timing previously proposed for the DSi decreases and the concentration changes through deep time, which would have major implications for the cycling of carbon and other key nutrients in the ocean. Here, we combine relevant genomic data with geological data and present new hypotheses regarding the impact of the evolution of biosilicifying organisms on the DSi inventory of the oceans throughout deep time. Although there is no fossil evidence for true silica biomineralization until the late Precambrian, the timing of the evolution of silica transporter genes suggests that bacterial silicon-related metabolism has been present in the oceans since the Archean with eukaryotic silicon metabolism already occurring in the Neoproterozoic. We hypothesize that biological processes have influenced oceanic DSi concentrations since the beginning of oxygenic photosynthesis.

【 授权许可】

Unknown