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Graptolite community responses to global climate change and the Late Ordovician mass extinction.
Proc Natl Acad Sci U S A. 2016 07 26; 113(30):8380-5.PN

Abstract

Mass extinctions disrupt ecological communities. Although climate changes produce stress in ecological communities, few paleobiological studies have systematically addressed the impact of global climate changes on the fine details of community structure with a view to understanding how changes in community structure presage, or even cause, biodiversity decline during mass extinctions. Based on a novel Bayesian approach to biotope assessment, we present a study of changes in species abundance distribution patterns of macroplanktonic graptolite faunas (∼447-444 Ma) leading into the Late Ordovician mass extinction. Communities at two contrasting sites exhibit significant decreases in complexity and evenness as a consequence of the preferential decline in abundance of dysaerobic zone specialist species. The observed changes in community complexity and evenness commenced well before the dramatic population depletions that mark the tipping point of the extinction event. Initially, community changes tracked changes in the oceanic water masses, but these relations broke down during the onset of mass extinction. Environmental isotope and biomarker data suggest that sea surface temperature and nutrient cycling in the paleotropical oceans changed sharply during the latest Katian time, with consequent changes in the extent of the oxygen minimum zone and phytoplankton community composition. Although many impacted species persisted in ephemeral populations, increased extinction risk selectively depleted the diversity of paleotropical graptolite species during the latest Katian and early Hirnantian. The effects of long-term climate change on habitats can thus degrade populations in ways that cascade through communities, with effects that culminate in mass extinction.

Authors+Show Affiliations

Department of Physics, Canisius College, Buffalo, NY 14208; sheets@canisius.edu.Department of Geology, University at Buffalo, The State University of New York, Buffalo, NY 14260;Department of Earth Sciences, St. Francis Xavier University, Antigonish, NS, Canada B2G 2W5;Department of Earth Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2;Institute of Geology, The Czech Academy of Sciences, 165 00 Prague 6, Czech Republic.Department of Geology, University at Buffalo, The State University of New York, Buffalo, NY 14260;Department of Geology, University at Buffalo, The State University of New York, Buffalo, NY 14260;

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

27432981

Citation

Sheets, H David, et al. "Graptolite Community Responses to Global Climate Change and the Late Ordovician Mass Extinction." Proceedings of the National Academy of Sciences of the United States of America, vol. 113, no. 30, 2016, pp. 8380-5.
Sheets HD, Mitchell CE, Melchin MJ, et al. Graptolite community responses to global climate change and the Late Ordovician mass extinction. Proc Natl Acad Sci U S A. 2016;113(30):8380-5.
Sheets, H. D., Mitchell, C. E., Melchin, M. J., Loxton, J., Štorch, P., Carlucci, K. L., & Hawkins, A. D. (2016). Graptolite community responses to global climate change and the Late Ordovician mass extinction. Proceedings of the National Academy of Sciences of the United States of America, 113(30), 8380-5. https://doi.org/10.1073/pnas.1602102113
Sheets HD, et al. Graptolite Community Responses to Global Climate Change and the Late Ordovician Mass Extinction. Proc Natl Acad Sci U S A. 2016 07 26;113(30):8380-5. PubMed PMID: 27432981.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Graptolite community responses to global climate change and the Late Ordovician mass extinction. AU - Sheets,H David, AU - Mitchell,Charles E, AU - Melchin,Michael J, AU - Loxton,Jason, AU - Štorch,Petr, AU - Carlucci,Kristi L, AU - Hawkins,Andrew D, Y1 - 2016/07/18/ PY - 2016/7/20/entrez PY - 2016/7/20/pubmed PY - 2018/2/6/medline KW - abundance KW - climate change KW - extinction KW - macroevolution KW - selection SP - 8380 EP - 5 JF - Proceedings of the National Academy of Sciences of the United States of America JO - Proc Natl Acad Sci U S A VL - 113 IS - 30 N2 - Mass extinctions disrupt ecological communities. Although climate changes produce stress in ecological communities, few paleobiological studies have systematically addressed the impact of global climate changes on the fine details of community structure with a view to understanding how changes in community structure presage, or even cause, biodiversity decline during mass extinctions. Based on a novel Bayesian approach to biotope assessment, we present a study of changes in species abundance distribution patterns of macroplanktonic graptolite faunas (∼447-444 Ma) leading into the Late Ordovician mass extinction. Communities at two contrasting sites exhibit significant decreases in complexity and evenness as a consequence of the preferential decline in abundance of dysaerobic zone specialist species. The observed changes in community complexity and evenness commenced well before the dramatic population depletions that mark the tipping point of the extinction event. Initially, community changes tracked changes in the oceanic water masses, but these relations broke down during the onset of mass extinction. Environmental isotope and biomarker data suggest that sea surface temperature and nutrient cycling in the paleotropical oceans changed sharply during the latest Katian time, with consequent changes in the extent of the oxygen minimum zone and phytoplankton community composition. Although many impacted species persisted in ephemeral populations, increased extinction risk selectively depleted the diversity of paleotropical graptolite species during the latest Katian and early Hirnantian. The effects of long-term climate change on habitats can thus degrade populations in ways that cascade through communities, with effects that culminate in mass extinction. SN - 1091-6490 UR - https://www.unboundmedicine.com/medline/citation/27432981/Graptolite_community_responses_to_global_climate_change_and_the_Late_Ordovician_mass_extinction_ L2 - http://www.pnas.org/cgi/pmidlookup?view=long&pmid=27432981 DB - PRIME DP - Unbound Medicine ER -