Temporal variation of planetary iron as a driver of evolution.
| Autor: | Wade J; Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, United Kingdom; jon.wade@earth.ox.ac.uk chris.ballentine@earth.ox.ac.uk alexander.drakesmith@imm.ox.ac.uk., Byrne DJ; Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS-Université de Lorraine, BP 20, F-54501 Vandoeuvre-lés-Nancy, France., Ballentine CJ; Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, United Kingdom; jon.wade@earth.ox.ac.uk chris.ballentine@earth.ox.ac.uk alexander.drakesmith@imm.ox.ac.uk., Drakesmith H; MRC (Medical Research Council) Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom jon.wade@earth.ox.ac.uk chris.ballentine@earth.ox.ac.uk alexander.drakesmith@imm.ox.ac.uk. |
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| Jazyk: | angličtina |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Dec 21; Vol. 118 (51). |
| DOI: | 10.1073/pnas.2109865118 |
| Abstrakt: | Iron is an irreplaceable component of proteins and enzyme systems required for life. This need for iron is a well-characterized evolutionary mechanism for genetic selection. However, there is limited consideration of how iron bioavailability, initially determined by planetary accretion but fluctuating considerably at global scale over geological time frames, has shaped the biosphere. We describe influences of iron on planetary habitability from formation events >4 Gya and initiation of biochemistry from geochemistry through oxygenation of the atmosphere to current host-pathogen dynamics. By determining the iron and transition element distribution within the terrestrial planets, planetary core formation is a constraint on both the crustal composition and the longevity of surface water, hence a planet's habitability. As such, stellar compositions, combined with metallic core-mass fraction, may be an observable characteristic of exoplanets that relates to their ability to support life. On Earth, the stepwise rise of atmospheric oxygen effectively removed gigatons of soluble ferrous iron from habitats, generating evolutionary pressures. Phagocytic, infectious, and symbiotic behaviors, dating from around the Great Oxygenation Event, refocused iron acquisition onto biotic sources, while eukaryotic multicellularity allows iron recycling within an organism. These developments allow life to more efficiently utilize a scarce but vital nutrient. Initiation of terrestrial life benefitted from the biochemical properties of abundant mantle/crustal iron, but the subsequent loss of iron bioavailability may have been an equally important driver of compensatory diversity. This latter concept may have relevance for the predicted future increase in iron deficiency across the food chain caused by elevated atmospheric CO Competing Interests: The authors declare no competing interest. (Copyright © 2021 the Author(s). Published by PNAS.) |
| Databáze: | MEDLINE |
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