1
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An Z, Zhou W, Zhang Z, Zhang X, Liu Z, Sun Y, Clemens SC, Wu L, Zhao J, Shi Z, Ma X, Yan H, Li G, Cai Y, Yu J, Sun Y, Li S, Zhang Y, Stepanek C, Lohmann G, Dong G, Cheng H, Liu Y, Jin Z, Li T, Hao Y, Lei J, Cai W. Mid-Pleistocene climate transition triggered by Antarctic Ice Sheet growth. Science 2024; 385:560-565. [PMID: 39088600 DOI: 10.1126/science.abn4861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/06/2023] [Accepted: 06/28/2024] [Indexed: 08/03/2024]
Abstract
Despite extensive investigation, the nature and causes of the Mid-Pleistocene Transition remain enigmatic. In this work, we assess its linkage to asynchronous development of bipolar ice sheets by synthesizing Pleistocene mid- to high-latitude proxy records linked to hemispheric ice sheet evolution. Our results indicate substantial growth of the Antarctic Ice Sheets (AISs) at 2.0 to 1.25 million years ago, preceding the rapid expansion of Northern Hemisphere Ice Sheets after ~1.25 million years ago. Proxy-model comparisons suggest that AIS and associated Southern Ocean sea ice expansion can induce northern high-latitude cooling and enhanced moisture transport to the Northern Hemisphere, thus triggering the Mid-Pleistocene Transition. The dynamic processes involved are crucial for assessing modern global warming that is already inducing asynchronous bipolar melting of ice sheets.
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Affiliation(s)
- Zhisheng An
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
- Interdisciplinary Research Center of Earth Science Frontier, Beijing Normal University, Beijing 100875, China
| | - Weijian Zhou
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
- Interdisciplinary Research Center of Earth Science Frontier, Beijing Normal University, Beijing 100875, China
| | - Zeke Zhang
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing 210023, China
| | - Xu Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- British Antarctic Survey, Cambridge CB3 0ET, UK
| | - Zhonghui Liu
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Department of Earth Sciences, The University of Hong Kong, Hong Kong, China
| | - Youbin Sun
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Steven C Clemens
- Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA
| | - Lixin Wu
- Laoshan Laboratory, Qingdao 266000, China
- Key Laboratory of Physical Oceanography/Institute for Advanced Ocean Studies, Ocean University of China, Qingdao 266100, China
| | - Jiaju Zhao
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhengguo Shi
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xiaolin Ma
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Hong Yan
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Gaojun Li
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing 210023, China
| | - Yanjun Cai
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jimin Yu
- Laoshan Laboratory, Qingdao 266000, China
- Research School of Earth Sciences, Australian National University, Canberra, ACT 2601, Australia
| | - Yuchen Sun
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, 27570 Bremerhaven, Germany
| | - Siqi Li
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu'ao Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Christian Stepanek
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, 27570 Bremerhaven, Germany
| | - Gerrit Lohmann
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, 27570 Bremerhaven, Germany
| | - Guocheng Dong
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Hai Cheng
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yu Liu
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Zhangdong Jin
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Tao Li
- Key Laboratory of Palaeobiology and Petroleum Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yifei Hao
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Jing Lei
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Xi'an Institute for Innovative Earth Environment Research, Xi'an 710061, China
| | - Wenju Cai
- State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
- Laoshan Laboratory, Qingdao 266000, China
- Key Laboratory of Physical Oceanography/Institute for Advanced Ocean Studies, Ocean University of China, Qingdao 266100, China
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2
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Clark PU, Shakun JD, Rosenthal Y, Köhler P, Bartlein PJ. Global and regional temperature change over the past 4.5 million years. Science 2024; 383:884-890. [PMID: 38386742 DOI: 10.1126/science.adi1908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 01/16/2024] [Indexed: 02/24/2024]
Abstract
Much of our understanding of Cenozoic climate is based on the record of δ18O measured in benthic foraminifera. However, this measurement reflects a combined signal of global temperature and sea level, thus preventing a clear understanding of the interactions and feedbacks of the climate system in causing global temperature change. Our new reconstruction of temperature change over the past 4.5 million years includes two phases of long-term cooling, with the second phase of accelerated cooling during the Middle Pleistocene Transition (1.5 to 0.9 million years ago) being accompanied by a transition from dominant 41,000-year low-amplitude periodicity to dominant 100,000-year high-amplitude periodicity. Changes in the rates of long-term cooling and variability are consistent with changes in the carbon cycle driven initially by geologic processes, followed by additional changes in the Southern Ocean carbon cycle.
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Affiliation(s)
- Peter U Clark
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
- School of Geography and Environmental Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Jeremy D Shakun
- Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA 02467, USA
| | - Yair Rosenthal
- Department of Marine and Coastal Science, Rutgers The State University, New Brunswick, NJ 08901, USA
- Department of Earth and Planetary Sciences, Rutgers The State University, New Brunswick, NJ 08901, USA
| | - Peter Köhler
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27570 Bremerhaven, Germany
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3
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Judd EJ, Tierney JE, Huber BT, Wing SL, Lunt DJ, Ford HL, Inglis GN, McClymont EL, O'Brien CL, Rattanasriampaipong R, Si W, Staitis ML, Thirumalai K, Anagnostou E, Cramwinckel MJ, Dawson RR, Evans D, Gray WR, Grossman EL, Henehan MJ, Hupp BN, MacLeod KG, O'Connor LK, Sánchez Montes ML, Song H, Zhang YG. The PhanSST global database of Phanerozoic sea surface temperature proxy data. Sci Data 2022; 9:753. [PMID: 36473868 PMCID: PMC9726822 DOI: 10.1038/s41597-022-01826-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 11/08/2022] [Indexed: 12/12/2022] Open
Abstract
Paleotemperature proxy data form the cornerstone of paleoclimate research and are integral to understanding the evolution of the Earth system across the Phanerozoic Eon. Here, we present PhanSST, a database containing over 150,000 data points from five proxy systems that can be used to estimate past sea surface temperature. The geochemical data have a near-global spatial distribution and temporally span most of the Phanerozoic. Each proxy value is associated with consistent and queryable metadata fields, including information about the location, age, and taxonomy of the organism from which the data derive. To promote transparency and reproducibility, we include all available published data, regardless of interpreted preservation state or vital effects. However, we also provide expert-assigned diagenetic assessments, ecological and environmental flags, and other proxy-specific fields, which facilitate informed and responsible reuse of the database. The data are quality control checked and the foraminiferal taxonomy has been updated. PhanSST will serve as a valuable resource to the paleoclimate community and has myriad applications, including evolutionary, geochemical, diagenetic, and proxy calibration studies.
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Affiliation(s)
- Emily J Judd
- Smithsonian National Museum of Natural History, Department of Paleobiology, Washington, DC, 20560, USA.
| | - Jessica E Tierney
- University of Arizona, Department of Geosciences, Tuscon, AZ, 85721, USA
| | - Brian T Huber
- Smithsonian National Museum of Natural History, Department of Paleobiology, Washington, DC, 20560, USA
| | - Scott L Wing
- Smithsonian National Museum of Natural History, Department of Paleobiology, Washington, DC, 20560, USA
| | - Daniel J Lunt
- University of Bristol, School of Geographical Sciences, Bristol, BS8 1SS, UK
| | - Heather L Ford
- Queen Mary University of London, School of Geography, London, E1 4NS, UK
| | - Gordon N Inglis
- University of Southampton, School of Ocean and Earth Science, National Oceanography Centre Southampton, Southampton, SO14 3ZH, UK
| | | | | | | | - Weimin Si
- Brown University, Department of Earth, Environmental and Planetary Sciences, Providence, RI, 02912, USA
| | - Matthew L Staitis
- University of Edinburgh, School of Geosciences, Edinburgh, EH8 9XP, UK
| | | | - Eleni Anagnostou
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148, Kiel, Germany
| | - Marlow Julius Cramwinckel
- University of Southampton, School of Ocean and Earth Science, National Oceanography Centre Southampton, Southampton, SO14 3ZH, UK
- Utrecht University, Department of Earth Sciences, Utrecht, 3584 CB, The Netherlands
| | - Robin R Dawson
- University of Massachusetts Amherst, Department of Geosciences, Amherst, MA, 01003, USA
| | - David Evans
- Goethe University Frankfurt, Institute of Geosciences, 60438, Frankfurt am Main, Germany
| | - William R Gray
- Université Paris-Saclay, Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvette, France
| | - Ethan L Grossman
- Texas A&M University, Department of Geology and Geophysics, College Station, TX, 77843, USA
| | - Michael J Henehan
- GFZ German Research Centre for Geosciences, Section 3.3 Earth Surface Geochemistry, 14473, Potsdam, Germany
| | - Brittany N Hupp
- Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, OR, 97331, USA
| | - Kenneth G MacLeod
- University of Missouri, Department of Geological Sciences, Columbia, MO, 65211, USA
| | - Lauren K O'Connor
- University of Manchester, Department of Earth and Environmental Sciences, Manchester, M13 9PL, UK
| | | | - Haijun Song
- China University of Geosciences, State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, Wuhan, 430074, China
| | - Yi Ge Zhang
- Texas A&M University, Department of Oceanography, College Station, TX, 77843, USA
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4
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Shackleton JD, Follows MJ, Thomas PJ, Omta AW. The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? CLIMATE DYNAMICS 2022; 60:4083-4098. [PMID: 37292246 PMCID: PMC10244291 DOI: 10.1007/s00382-022-06544-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 10/14/2022] [Indexed: 06/10/2023]
Abstract
Glacial-interglacial cycles constitute large natural variations in Earth's climate. The Mid-Pleistocene Transition (MPT) marks a shift of the dominant periodicity of these climate cycles from ∼ 40 to ∼ 100 kyr. Recently, it has been suggested that this shift resulted from a gradual increase in the internal period (or equivalently, a decrease in the natural frequency) of the system. As a result, the system would then have locked to ever higher multiples of the external forcing period. We find that the internal period is sensitive to the strength of positive feedbacks in the climate system. Using a carbon cycle model in which feedbacks between calcifier populations and ocean alkalinity mediate atmospheric CO2 , we simulate stepwise periodicity changes similar to the MPT through such a mechanism. Due to the internal dynamics of the system, the periodicity shift occurs up to millions of years after the change in the feedback strength is imposed. This suggests that the cause for the MPT may have occurred a significant time before the observed periodicity shift.
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Affiliation(s)
- J. D. Shackleton
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - M. J. Follows
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - P. J. Thomas
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, Cleveland, OH 44106 USA
| | - A. W. Omta
- Department of Earth, Environmental, and Planetary Sciences, Case Western Reserve University, Cleveland, OH 44106 USA
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5
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Thomas NC, Bradbury HJ, Hodell DA. Changes in North Atlantic deep-water oxygenation across the Middle Pleistocene Transition. Science 2022; 377:654-659. [PMID: 35926027 DOI: 10.1126/science.abj7761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The oxygen concentrations of oceanic deep-water and atmospheric carbon dioxide (pCO2) are intrinsically linked through organic carbon remineralization and storage as dissolved inorganic carbon in the deep sea. We present a high-resolution reconstruction of relative changes in oxygen concentration in the deep North Atlantic for the past 1.5 million years using the carbon isotope gradient between epifaunal and infaunal benthic foraminifera species as a proxy for paleo-oxygen. We report a significant (>40 micromole per kilogram) reduction in glacial Atlantic deep-water oxygenation at ~960 thousand to 900 thousand years ago that coincided with increased continental ice volume and a major change in ocean thermohaline circulation. Paleo-oxygen results support a scenario of decreasing deep-water oxygen concentrations, increased respired carbon storage, and a reduction in glacial pCO2 across the Middle Pleistocene Transition.
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Affiliation(s)
- Nicola C Thomas
- Department of Earth Science, University of Cambridge, Cambridge, UK
| | | | - David A Hodell
- Department of Earth Science, University of Cambridge, Cambridge, UK
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6
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Cowart DA, Schiaparelli S, Alvaro MC, Cecchetto M, Le Port A, Jollivet D, Hourdez S. Origin, diversity, and biogeography of Antarctic scale worms (Polychaeta: Polynoidae): a wide-scale barcoding approach. Ecol Evol 2022; 12:e9093. [PMID: 35866013 PMCID: PMC9288932 DOI: 10.1002/ece3.9093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 05/06/2022] [Accepted: 05/23/2022] [Indexed: 11/14/2022] Open
Abstract
The Antarctic marine environment hosts diversified and highly endemic benthos owing to its unique geologic and climatic history. Current warming trends have increased the urgency of understanding Antarctic species history to predict how environmental changes will impact ecosystem functioning. Antarctic benthic lineages have traditionally been examined under three hypotheses: (1) high endemism and local radiation, (2) emergence of deep-sea taxa through thermohaline circulation, and (3) species migrations across the Polar Front. In this study, we investigated which hypotheses best describe benthic invertebrate origins by examining Antarctic scale worms (Polynoidae). We amassed 691 polynoid sequences from the Southern Ocean and neighboring areas: the Kerguelen and Tierra del Fuego (South America) archipelagos, the Indian Ocean, and waters around New Zealand. We performed phylogenetic reconstructions to identify lineages across geographic regions, aided by mitochondrial markers cytochrome c oxidase subunit I (Cox1) and 16S ribosomal RNA (16S). Additionally, we produced haplotype networks at the species scale to examine genetic diversity, biogeographic separations, and past demography. The Cox1 dataset provided the most illuminating insights into the evolution of polynoids, with a total of 36 lineages identified. Eunoe sp. was present at Tierra del Fuego and Kerguelen, in favor of the latter acting as a migration crossroads. Harmothoe fuligineum, widespread around the Antarctic continent, was also present but isolated at Kerguelen, possibly resulting from historical freeze-thaw cycles. The genus Polyeunoa appears to have diversified prior to colonizing the continent, leading to the co-occurrence of at least three cryptic species around the Southern and Indian Oceans. Analyses identified that nearly all populations are presently expanding following a bottleneck event, possibly caused by habitat reduction from the last glacial episodes. Findings support multiple origins for contemporary Antarctic polynoids, and some species investigated here provide information on ancestral scenarios of (re)colonization. First, it is apparent that species collected from the Antarctic continent are endemic, as the absence of closely related species in the Kerguelen and Tierra del Fuego datasets for most lineages argues in favor of Hypothesis 1 of local origin. Next, Eunoe sp. and H. fuligineum, however, support the possibility of Kerguelen and other sub-Antarctic islands acting as a crossroads for larvae of some species, in support of Hypothesis 3. Finally, the genus Polyeunoa, conversely, is found at depths greater than 150 m and may have a deep origin, in line with Hypothesis 2. These "non endemic" groups, nevertheless, have a distribution that is either north or south of the Antarctic Polar Front, indicating that there is still a barrier to dispersal, even in the deep sea.
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Affiliation(s)
- Dominique A. Cowart
- Department of Evolution, Ecology, and BehaviorUniversity of Illinois at Urbana – ChampaignUrbanaIllinoisUSA
- Company for Open Ocean Observations and Logging (COOOL)La RéunionFrance
| | - Stefano Schiaparelli
- Department of Earth, Environmental and Life Science (DiSTAV)University of GenoaGenoaItaly
- Italian National Antarctic Museum (MNA, Section of Genoa)University of GenoaGenoaItaly
| | - Maria Chiara Alvaro
- Department of Earth, Environmental and Life Science (DiSTAV)University of GenoaGenoaItaly
| | - Matteo Cecchetto
- Department of Earth, Environmental and Life Science (DiSTAV)University of GenoaGenoaItaly
- Italian National Antarctic Museum (MNA, Section of Genoa)University of GenoaGenoaItaly
| | - Anne‐Sophie Le Port
- CNRS UMR 7144 ‘Adaptation et Diversité en Milieux Marins’ (AD2M)Team ‘Dynamique de la Diversité Marine’ (DyDiv), Station Biologique de RoscoffSorbonne UniversitéRoscoffFrance
| | - Didier Jollivet
- CNRS UMR 7144 ‘Adaptation et Diversité en Milieux Marins’ (AD2M)Team ‘Dynamique de la Diversité Marine’ (DyDiv), Station Biologique de RoscoffSorbonne UniversitéRoscoffFrance
| | - Stephane Hourdez
- CNRS UMR 7144 ‘Adaptation et Diversité en Milieux Marins’ (AD2M)Team ‘Dynamique de la Diversité Marine’ (DyDiv), Station Biologique de RoscoffSorbonne UniversitéRoscoffFrance
- Laboratoire d'Ecogéochimie des Environnements Benthiques (LECOB), Observatoire Océanologique de BanyulsUMR 8222 CNRS‐Sorbonne UniversitéBanyuls‐sur‐merFrance
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7
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Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years. Nat Commun 2022; 13:2044. [PMID: 35440628 PMCID: PMC9018689 DOI: 10.1038/s41467-022-29642-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 03/25/2022] [Indexed: 11/08/2022] Open
Abstract
The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a 5 to 15-fold increase in dust deposition during glacials and a 2 to 5-fold increase in biogenic silica deposition, reflecting higher ocean productivity during interglacials. This antiphasing persisted throughout the last 25 glacial cycles. Dust deposition became more pronounced across the Mid-Pleistocene Transition (MPT) in the Southern Hemisphere, with an abrupt shift suggesting more severe glaciations since ~0.9 Ma. Productivity was intermediate pre-MPT, lowest during the MPT and highest since 0.4 Ma. Generally, glacials experienced extended sea-ice cover, reduced bottom-water export and Weddell Gyre dynamics, which helped lower atmospheric CO2 levels.
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Lau SCY, Strugnell JM, Sands CJ, Silva CNS, Wilson NG. Evolutionary innovations in Antarctic brittle stars linked to glacial refugia. Ecol Evol 2021; 11:17428-17446. [PMID: 34938519 PMCID: PMC8668817 DOI: 10.1002/ece3.8376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 12/31/2022] Open
Abstract
The drivers behind evolutionary innovations such as contrasting life histories and morphological change are central questions of evolutionary biology. However, the environmental and ecological contexts linked to evolutionary innovations are generally unclear. During the Pleistocene glacial cycles, grounded ice sheets expanded across the Southern Ocean continental shelf. Limited ice-free areas remained, and fauna were isolated from other refugial populations. Survival in Southern Ocean refugia could present opportunities for ecological adaptation and evolutionary innovation. Here, we reconstructed the phylogeographic patterns of circum-Antarctic brittle stars Ophionotus victoriae and O. hexactis with contrasting life histories (broadcasting vs brooding) and morphology (5 vs 6 arms). We examined the evolutionary relationship between the two species using cytochrome c oxidase subunit I (COI) data. COI data suggested that O. victoriae is a single species (rather than a species complex) and is closely related to O. hexactis (a separate species). Since their recent divergence in the mid-Pleistocene, O. victoriae and O. hexactis likely persisted differently throughout glacial maxima, in deep-sea and Antarctic island refugia, respectively. Genetic connectivity, within and between the Antarctic continental shelf and islands, was also observed and could be linked to the Antarctic Circumpolar Current and local oceanographic regimes. Signatures of a probable seascape corridor linking connectivity between the Scotia Sea and Prydz Bay are also highlighted. We suggest that survival in Antarctic island refugia was associated with increase in arm number and a switch from broadcast spawning to brooding in O. hexactis, and propose that it could be linked to environmental changes (such as salinity) associated with intensified interglacial-glacial cycles.
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Affiliation(s)
- Sally C. Y. Lau
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Science and EngineeringJames Cook UniversityTownsvilleQldAustralia
| | - Jan M. Strugnell
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Science and EngineeringJames Cook UniversityTownsvilleQldAustralia
- Department of Ecology, Environment and EvolutionSchool of Life SciencesLa Trobe UniversityMelbourneVicAustralia
- Securing Antarctica's Environmental FutureJames Cook UniversityTownsvilleQldAustralia
| | - Chester J. Sands
- British Antarctic SurveyNatural Environment Research CouncilCambridgeUK
| | - Catarina N. S. Silva
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Science and EngineeringJames Cook UniversityTownsvilleQldAustralia
| | - Nerida G. Wilson
- Collections & ResearchWestern Australian MuseumWelshpoolWAAustralia
- School of Biological SciencesUniversity of Western AustraliaPerthWAAustralia
- Securing Antarctica's Environmental FutureWestern Australian MuseumWelshpoolWAAustralia
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9
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Evidence for a Northern Hemispheric trigger of the 100,000-y glacial cyclicity. Proc Natl Acad Sci U S A 2021; 118:2020260118. [PMID: 34750249 DOI: 10.1073/pnas.2020260118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2021] [Indexed: 11/18/2022] Open
Abstract
The causes of the Mid-Pleistocene Transition, the shift from ∼41-ky to 100-ky interglacial-glacial cycles and more intense ice ages, remain intensely debated, as this fundamental change occurred between ∼1,250 and 650 ka without substantial changes in astronomical climate forcings. Recent studies disagree about the relative importance of events and processes in the Northern and Southern Hemispheres, as well as whether the shift occurred gradually over several interglacial-glacial cycles or abruptly at ∼900 ka. We address these issues using a north-to-south reconstruction of the Atlantic arm of the global meridional overturning ocean circulation, a primary means for distributing heat around the globe, using neodymium (Nd) isotopes. Results reveal a period of intense erosion affecting the cratonic shields surrounding the North Atlantic between Marine Isotope Stages (MIS) 27 and 25 (∼980 and 950 ka), reflected by unusually low Nd isotope ratios in deep North Atlantic seawater. This episode preceded a major ocean circulation weakening between MIS 25 and 21 (950 and 860 ka) that coincided with the first ∼100-ky-long interglacial-glacial onset of Northern Hemisphere glaciation at around 2.4 to 2.8 Ma. The data point to a Northern Hemisphere-sourced initiation for the transition, possibly induced through regolith loss and increased exposure of the crystalline bedrock, which would lead to increased friction, enabling larger ice sheets that are characteristic of the 100-ky interglacial-glacial cycles.
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10
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Westbury MV, Thompson KF, Louis M, Cabrera AA, Skovrind M, Castruita JAS, Constantine R, Stevens JR, Lorenzen ED. Ocean-wide genomic variation in Gray's beaked whales, Mesoplodon grayi. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201788. [PMID: 33959341 PMCID: PMC8074979 DOI: 10.1098/rsos.201788] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
The deep oceans of the Southern Hemisphere are home to several elusive and poorly studied marine megafauna. In the absence of robust observational data for these species, genetic data can aid inferences on population connectivity, demography and ecology. A previous investigation of genetic diversity and population structure in Gray's beaked whale (Mesoplodon grayi) from Western Australia and New Zealand found high levels of mtDNA diversity, no geographic structure and stable demographic history. To further investigate phylogeographic and demographic patterns across their range, we generated complete mitochondrial and partial nuclear genomes of 16 of the individuals previously analysed and included additional samples from South Africa (n = 2) and South Australia (n = 4), greatly expanding the spatial range of genomic data for the species. Gray's beaked whales are highly elusive and rarely observed, and our data represents a unique and geographically broad dataset. We find relatively high levels of diversity in the mitochondrial genome, despite an absence of population structure at the mitochondrial and nuclear level. Demographic analyses suggest these whales existed at stable levels over at least the past 1.1 million years, with an approximately twofold increase in female effective population size approximately 250 thousand years ago, coinciding with a period of increased Southern Ocean productivity, sea surface temperature and a potential expansion of suitable habitat. Our results suggest that Gray's beaked whales are likely to be resilient to near-future ecosystem changes, facilitating their conservation. Our study demonstrates the utility of low-effort shotgun sequencing in providing ecological information on highly elusive species.
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Affiliation(s)
| | | | - M. Louis
- GLOBE Institute, University of Copenhagen, Denmark
| | | | - M. Skovrind
- GLOBE Institute, University of Copenhagen, Denmark
| | | | - R. Constantine
- School of Biological Sciences and Institute of Marine Science, University of Auckland, New Zealand
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11
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Köhler P, van de Wal RSW. Interglacials of the Quaternary defined by northern hemispheric land ice distribution outside of Greenland. Nat Commun 2020; 11:5124. [PMID: 33046715 PMCID: PMC7550566 DOI: 10.1038/s41467-020-18897-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/18/2020] [Indexed: 11/16/2022] Open
Abstract
Glacial/interglacial dynamics during the Quaternary were suggested to be mainly driven by obliquity (41-kyr periodicity), including irregularities during the last 1 Myr that resulted in on average 100-kyr cycles. Here, we investigate this so-called Mid-Pleistocene Transition via model-based deconvolution of benthic δ18O, redefining interglacials by lack of substantial northern hemispheric land ice outside of Greenland. We find that in 67%, 88% and 52% of the obliquity cycles during the early, middle and late Quaternary, respectively, a glacial termination is realized leading to irregular appearances of new interglacials during various parts of the last 2.6 Myr. This finding suggests that the proposed idea of terminations leading to new interglacials in the Quaternary as obliquity driven with growing influence of land ice volume on the timing of deglaciations during the last 1 Myr might be too simple. Alternatively, the land ice-based definition of interglacials needs revision if applied to the entire Quaternary. This study presents a new definition of interglacials during the Quaternary. The authors find the appearance of interglacials is in general following the 41-kyr cycle of obliquity with various exceptions, suggesting a more complex physical mechanism triggering glacial terminations.
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Affiliation(s)
- Peter Köhler
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung (AWI), P.O. Box 12 01 61, Bremerhaven, 27515, Germany.
| | - Roderik S W van de Wal
- Institute for Marine and Atmospheric Research Utrecht (IMAU) and Faculty of Geosciences, Department of Physical Geography, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, The Netherlands
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12
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Petrick B, Martínez-García A, Auer G, Reuning L, Auderset A, Deik H, Takayanagi H, De Vleeschouwer D, Iryu Y, Haug GH. Glacial Indonesian Throughflow weakening across the Mid-Pleistocene Climatic Transition. Sci Rep 2019; 9:16995. [PMID: 31740711 PMCID: PMC6861309 DOI: 10.1038/s41598-019-53382-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/29/2019] [Indexed: 11/30/2022] Open
Abstract
The Indonesian Throughflow (ITF) controls the oceanic flux of heat and salt between the Pacific and Indian Oceans and therewith plays an important role in modulating the meridional overturning circulation and low latitude hydrological cycle. Here, we report new sea surface temperature and aridity records from the west coast of Australia (IODP Site U1460), which allow us to assess the sensitivity of the eastern Indian Ocean to the major reorganization of Earth’s climate that occurred during the Mid-Pleistocene Transition. Our records indicate glacial coolings at 1.55 and 0.65 million years ago that are best explained by a weakening of the ITF as a consequence of global sea level and tectonic changes. These coincide with the development of pronounced gradients in the carbon isotope composition of the different ocean basins and with substantial changes in regional aridity, suggesting that the restrictions of the ITF influenced both the evolution of global ocean circulation and the development of the modern hydrological cycle in Western Australia.
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Affiliation(s)
- Benjamin Petrick
- Max Planck Institute for Chemistry, Climate Geochemistry Department, Hahn-Meitner-Weg 1, 55128, Mainz, Germany.
| | - Alfredo Martínez-García
- Max Planck Institute for Chemistry, Climate Geochemistry Department, Hahn-Meitner-Weg 1, 55128, Mainz, Germany
| | - Gerald Auer
- Department of Biogeochemistry Frontier Bldg, 4F, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan
| | - Lars Reuning
- Kiel University, Institute for Geosciences, Ludewig-Meyn-Str. 10, 24118, Kiel, Germany.,RWTH Aachen University, Geological Institute, Wüllnerstrasse 2, 52062, Aachen, Germany
| | - Alexandra Auderset
- Max Planck Institute for Chemistry, Climate Geochemistry Department, Hahn-Meitner-Weg 1, 55128, Mainz, Germany
| | - Hanaa Deik
- RWTH Aachen University, Geological Institute, Wüllnerstrasse 2, 52062, Aachen, Germany
| | - Hideko Takayanagi
- Institute of Geology and Paleontology, Tohoku University, Aobayama, Sendai, 980-8578, Japan
| | - David De Vleeschouwer
- MARUM-Center for Marine and Environmental Sciences, Klagenfurterstraße 2-4, Bremen, 28359, Germany
| | - Yasufumi Iryu
- RWTH Aachen University, Geological Institute, Wüllnerstrasse 2, 52062, Aachen, Germany
| | - Gerald H Haug
- Max Planck Institute for Chemistry, Climate Geochemistry Department, Hahn-Meitner-Weg 1, 55128, Mainz, Germany.,Geologisches Institut, Eidgenössische Technische Hochschule Zürich, 8092, Zürich, Switzerland
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13
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Affiliation(s)
- Laurie Menviel
- Climate Change Research Center, PANGEA, University of New South Wales, Sydney, NSW 2052, Australia.
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