Severe selenium depletion in the Phanerozoic oceans as a factor in three global mass extinction events

Abstract

Selenium (Se) is one of the key trace elements required by all animal and most plant life, and Se deficiencies in the food chain cause pathologies or death. Here we show from new geochemical analyses of trace elements in Phanerozoicmarine pyrite that sustained periods of severe Se depletion in the past oceans correlate closely with three major mass extinction events, at the end of the Ordovician, Devonian and Triassic periods. These represent periods of Se depletion >1.5-2 orders of magnitude lower than current ocean abundances, being within the range to cause severe pathological damage in extant Se-reliant organisms. Accordingly Se depletion may have been one of several factors in these complex extinction scenarios. Recovery from the depletion/extinction events is likely part of a natural marine cycle, although rapid rises in global oxygen from sudden major increases in marine productivity and plant biomass after each extinction event may also have played a crucial role.

Antisense inhibition of selenoprotein synthesis by Zika virus may contribute to neurological disorders and microcephaly by mimicking SePP1 knockout and the genetic disease progressive cerebello-cerebral atrophy

“…Selenium is an essential dietary trace element, having the lowest concentration in the earth's crust of any nutrient element, and whose bioavailability in the food chain varies widely by geographical location and agricultural practices [25]. Perhaps the most dramatic example of its critical importance for living organisms is evidence that periods of severe selenium depletion in Earth's oceans correlate closely with three major mass extinction events between 500 and 200 million years ago [26]. In regard to our results involving ZIKV, it is significant that dietary selenium status has been associated with the pathogenesis and risk of disease progression for a number of viruses, almost all of which are RNA viruses (a point which we will revisit below).…”

Late Devonian and Early Carboniferous alpha diversity, ecospace occupation, vertebrate assemblages and bio-events of southeastern Morocco

“…Fundamental environmental perturbations and evolutionary changes in vertebrates and invertebrates were widely reported to have occurred during the Late Devonian (e. g. House, 1985;McGhee, 1988;Walliser, 1996;Algeo et al, 1995Algeo et al, , 2001Algeo and Scheckler, 1998;Caplan and Bustin, 1999;Murphy et al, 2000;Joachimski and Buggisch, 2002;Goddéris and Joachimski, 2004;Racki, 2005;Bond and Wignall, 2008;Sallan and Coates, 2010;Sallan and Galimberti, 2015;Long et al, 2015). Two biotic crises that strongly affected global biota were the Kellwasser and Hangenberg crises (Buggisch, 1991;Kaiser et al, 2006Kaiser et al, , 2008Kaiser et al, , 2015Carmichael et al, 2015;Becker et al, 2016); in addition small-scale events such as the Condroz (Becker, 1993), Annulata House, 1997, 2000;Sandberg et al, 2002;Korn, 2004;Racka, 2010;Hartenfels and Becker, 2016a) and Dasberg events Hartenfels, 2011;Kaiser et al, 2011) have been recognized in Frasnian and Famennian successions (House, 1985(House, , 2002Walliser, 1996; Table 1).…”

From success to persistence: Identifying an evolutionary regime shift in the diverse Paleozoic aquatic arthropod group Eurypterida, driven by the Devonian biotic crisis

“…Meanwhile, selenium depletion has been found associated with a number of extinction events throughout the Phanerozoic, including horizons at the end‐Emsian and during the Famennian (Long et al. ). The pervasive nature of anoxia and repeated periods of selenium depletion throughout the Middle and Upper Devonian suggests a protracted period of environmental stress from the Emsian onwards with further perturbations such as rapid glaciation adding stress to an ecosystem already in crisis.…”