Biosilicification drives a decline of dissolved si in the oceans through geologic time

Forskningsoutput: TidskriftsbidragÖversiktsartikel

Abstract

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.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • Stellenbosch University
  • Naturhistoriska riksmuseet
  • University of Bristol
  • University of Cambridge
  • Earthwatch Institute
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Geologi
  • Geokemi

Nyckelord

Originalspråkengelska
Artikelnummer397
TidskriftFrontiers in Marine Science
Volym4
Utgåva nummerDEC
StatusPublished - 2017 dec 11
PublikationskategoriForskning
Peer review utfördJa