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Furness LH, Kersten O, Boilard A, Keith-Diagne L, Brito C, Barrett JH, Kitchener A, Sabin R, Lavery S, Plön S, Star B. Population structure of Dugong dugon across the Indo-Pacific revealed by historical mitogenomes. ROYAL SOCIETY OPEN SCIENCE 2024; 11:240599. [PMID: 39113775 PMCID: PMC11304337 DOI: 10.1098/rsos.240599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/31/2024] [Accepted: 06/13/2024] [Indexed: 08/10/2024]
Abstract
Sirenia, an iconic marine taxon with a tropical and subtropical worldwide distribution, face an uncertain future. All species are designated 'Vulnerable' to extinction by the IUCN. Nonetheless, a comprehensive understanding of geographic structuring across the global range is lacking, impeding our ability to highlight particularly vulnerable populations for conservation priority. Here, we use ancient DNA to investigate dugong (Dugong dugon) population structure, analysing 56 mitogenomes from specimens comprising the known historical range. Our results reveal geographically structured and distinct monophyletic clades characterized by contrasting evolutionary histories. We observe deep-rooted and divergent lineages in the East (Indo-Pacific) and obtain new evidence for the relatively recent dispersal of dugongs into the western Indian Ocean. All populations are significantly differentiated from each other with western populations having approximately 10-fold lower levels of genetic variation than eastern Indo-Pacific populations. Additionally, we find a significant temporal loss of genetic diversity in western Indian Ocean dugongs since the mid-twentieth century, as well as a decline in population size beginning approximately 1000 years ago. Our results add to the growing body of evidence that dugong populations are becoming ever more susceptible to ongoing human action and global climate change.
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Affiliation(s)
- Lydia Hildebrand Furness
- Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo0313, Norway
| | - Oliver Kersten
- Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo0313, Norway
| | - Aurélie Boilard
- Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo0313, Norway
| | - Lucy Keith-Diagne
- African Aquatic Conservation Fund, BP 80 Joal23015, Senegal, West Africa
| | | | - James H. Barrett
- Norwegian University of Science and Technology, Trondheim7491, Norway
| | - Andrew Kitchener
- Department of Natural Sciences, National Museums Scotland, EdinburghEH1 1JF, UK
- School of Geosciences, University of Edinburgh, EdinburghEH10 5HF, UK
| | - Richard Sabin
- Vertebrates Division, Natural History Museum, LondonSW7 5BD, UK
| | - Shane Lavery
- School of Biological Sciences, University of Auckland, Auckland1010, New Zealand
| | - Stephanie Plön
- Department of Pathology, Stellenbosch University, Stellenbosch, South Africa
- Bayworld Centre for Research and Education, Port Elizabeth, 7602, South Africa
| | - Bastiaan Star
- Center for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo0313, Norway
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2
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Pyenson ND. How teeth, tusks and horny pads evolved together in sea cows. Proc Biol Sci 2024; 291:20241154. [PMID: 39137887 PMCID: PMC11321848 DOI: 10.1098/rspb.2024.1154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/13/2024] [Accepted: 07/23/2024] [Indexed: 08/15/2024] Open
Affiliation(s)
- Nicholas D. Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC20013-7012, USA
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3
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Tsai CH, Goedert JL, Boessenecker RW. The oldest mysticete in the Northern Hemisphere. Curr Biol 2024; 34:1794-1800.e3. [PMID: 38552627 DOI: 10.1016/j.cub.2024.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 02/27/2024] [Accepted: 03/08/2024] [Indexed: 04/25/2024]
Abstract
Extant baleen whales (Mysticeti) uniquely use keratinous baleen for filter-feeding and lack dentition, but the fossil record clearly shows that "toothed" baleen whales first appeared in the Late Eocene.1 Globally, only two Eocene mysticetes have been found, and both are from the Southern Hemisphere: Mystacodon selenensis from Peru, 36.4 mega-annum (Ma) ago1,2 and Llanocetus denticrenatus from Antarctica, 34.2 Ma ago.3,4 Based on a partial skull from the lower part of the Lincoln Creek Formation in Washington State, USA, we describe the Northern Hemisphere's geochronologically earliest mysticete, Fucaia humilis sp. nov. Geology, biostratigraphy, and magnetostratigraphy places Fucaia humilis sp. nov. in the latest Eocene (ca. 34.5 Ma ago, near the Eocene/Oligocene transition at 33.9 Ma ago), approximately coeval with the oldest record of fossil kelps, also in the northeastern Pacific.5 This observation leads to our hypothesis that the origin and development of a relatively stable, nutrient-rich kelp ecosystem5,6 in the latest Eocene may have fostered the radiation of small-sized toothed mysticetes (Family Aetiocetidae) in the North Pacific basin, a stark contrast to the larger Llanocetidae (whether Mystacodon belongs to llanocetids or another independent clade remains unresolved) with the latest Eocene onset of the Antarctic Circumpolar Current in the Southern Hemisphere.7,8,9 Our discovery suggests that disparate mechanisms and ecological scenarios may have nurtured contrasting early mysticete evolutionary histories in the Northern and Southern hemispheres.
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Affiliation(s)
- Cheng-Hsiu Tsai
- Department of Life Science and Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei 10617, Taiwan; Department of Geology, National Museum of Nature and Science, Tsukuba 305-0005, Japan.
| | - James L Goedert
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98105, USA.
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4
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Motani R, Pyenson ND. Downsizing a heavyweight: factors and methods that revise weight estimates of the giant fossil whale Perucetus colossus. PeerJ 2024; 12:e16978. [PMID: 38436015 PMCID: PMC10909350 DOI: 10.7717/peerj.16978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/29/2024] [Indexed: 03/05/2024] Open
Abstract
Extremes in organismal size have broad interest in ecology and evolution because organismal size dictates many traits of an organism's biology. There is particular fascination with identifying upper size extremes in the largest vertebrates, given the challenges and difficulties of measuring extant and extinct candidates for the largest animal of all time, such as whales, terrestrial non-avian dinosaurs, and extinct marine reptiles. The discovery of Perucetus colossus, a giant basilosaurid whale from the Eocene of Peru, challenged many assumptions about organismal extremes based on reconstructions of its body weight that exceeded reported values for blue whales (Balaenoptera musculus). Here we present an examination of a series of factors and methodological approaches to assess reconstructing body weight in Perucetus, including: data sources from large extant cetaceans; fitting published body mass estimates to body outlines; testing the assumption of isometry between skeletal and body masses, even with extrapolation; examining the role of pachyostosis in body mass reconstructions; addressing method-dependent error rates; and comparing Perucetus with known physiological and ecological limits for living whales, and Eocene oceanic productivity. We conclude that Perucetus did not exceed the body mass of today's blue whales. Depending on assumptions and methods, we estimate that Perucetus weighed 60-70 tons assuming a length 17 m. We calculated larger estimates potentially as much as 98-114 tons at 20 m in length, which is far less than the direct records of blue whale weights, or the 270 ton estimates that we calculated for body weights of the largest blue whales measured by length.
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Affiliation(s)
- Ryosuke Motani
- Department of Earth and Planetary Sciences, University of California, Davis, Davis, California, United States
| | - Nicholas D. Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, District of Columbia, United States
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5
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Christianen MJA, Smulders FOH, Vonk JA, Becking LE, Bouma TJ, Engel SM, James RK, Nava MI, de Smit JC, van der Zee JP, Palsbøll PJ, Bakker ES. Seagrass ecosystem multifunctionality under the rise of a flagship marine megaherbivore. GLOBAL CHANGE BIOLOGY 2023; 29:215-230. [PMID: 36330798 PMCID: PMC10099877 DOI: 10.1111/gcb.16464] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/09/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Large grazers (megaherbivores) have a profound impact on ecosystem functioning. However, how ecosystem multifunctionality is affected by changes in megaherbivore populations remains poorly understood. Understanding the total impact on ecosystem multifunctionality requires an integrative ecosystem approach, which is especially challenging to obtain in marine systems. We assessed the effects of experimentally simulated grazing intensity scenarios on ecosystem functions and multifunctionality in a tropical Caribbean seagrass ecosystem. As a model, we selected a key marine megaherbivore, the green turtle, whose ecological role is rapidly unfolding in numerous foraging areas where populations are recovering through conservation after centuries of decline, with an increase in recorded overgrazing episodes. To quantify the effects, we employed a novel integrated index of seagrass ecosystem multifunctionality based upon multiple, well-recognized measures of seagrass ecosystem functions that reflect ecosystem services. Experiments revealed that intermediate turtle grazing resulted in the highest rates of nutrient cycling and carbon storage, while sediment stabilization, decomposition rates, epifauna richness, and fish biomass are highest in the absence of turtle grazing. In contrast, intense grazing resulted in disproportionally large effects on ecosystem functions and a collapse of multifunctionality. These results imply that (i) the return of a megaherbivore can exert strong effects on coastal ecosystem functions and multifunctionality, (ii) conservation efforts that are skewed toward megaherbivores, but ignore their key drivers like predators or habitat, will likely result in overgrazing-induced loss of multifunctionality, and (iii) the multifunctionality index shows great potential as a quantitative tool to assess ecosystem performance. Considerable and rapid alterations in megaherbivore abundance (both through extinction and conservation) cause an imbalance in ecosystem functioning and substantially alter or even compromise ecosystem services that help to negate global change effects. An integrative ecosystem approach in environmental management is urgently required to protect and enhance ecosystem multifunctionality.
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Affiliation(s)
- Marjolijn J. A. Christianen
- Aquatic Ecology and Water Quality Management GroupWageningen University & ResearchWageningenThe Netherlands
- Marine Evolution and Conservation GroupGroningen Institute for Evolutionary Life Sciences, University of GroningenGroningenThe Netherlands
| | - Fee O. H. Smulders
- Aquatic Ecology and Water Quality Management GroupWageningen University & ResearchWageningenThe Netherlands
| | - Jan Arie Vonk
- Department of Freshwater and Marine EcologyInstitute for Biodiversity and Ecosystem Dynamics (IBED), University of AmsterdamAmsterdamThe Netherlands
| | - Leontine E. Becking
- Aquaculture and Fisheries groupWageningen University & Research CentreWageningenThe Netherlands
| | - Tjeerd J. Bouma
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research (NIOZ)YersekeThe Netherlands
- Department of Physical Geography, Faculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
| | - Sabine M. Engel
- STINAPA, Bonaire National Parks FoundationBonaireCaribbean Netherlands
| | - Rebecca K. James
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research (NIOZ)YersekeThe Netherlands
- Biogeochemistry and Modeling of the Earth System GroupUniversité libre de BruxellesBruxellesBelgium
| | - Mabel I. Nava
- Sea Turtle Conservation BonaireBonaireCaribbean Netherlands
| | - Jaco C. de Smit
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research (NIOZ)YersekeThe Netherlands
- Department of Physical Geography, Faculty of GeosciencesUtrecht UniversityUtrechtThe Netherlands
| | - Jurjan P. van der Zee
- Marine Evolution and Conservation GroupGroningen Institute for Evolutionary Life Sciences, University of GroningenGroningenThe Netherlands
| | - Per J. Palsbøll
- Marine Evolution and Conservation GroupGroningen Institute for Evolutionary Life Sciences, University of GroningenGroningenThe Netherlands
- Center for Coastal StudiesProvincetownMassachusettsUSA
| | - Elisabeth S. Bakker
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
- Wildlife Ecology and Conservation Group, Wageningen University & ResearchWageningenThe Netherlands
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6
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Roopnarine PD, Banker RMW, Sampson SD. Impact of the extinct megaherbivore Steller's sea cow (Hydrodamalis gigas) on kelp forest resilience. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.983558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Giant kelp forests off the west coast of North America are maintained primarily by sea otter (Enhydra lutris) and sunflower sea star (Pycnopodia helianthoides) predation of sea urchins. Human hunting of sea otters in historical times, together with a marine heat wave and sea star wasting disease epidemic in the past decade, devastated these predators, leading to widespread occurrences of urchin barrens. Since the late Neogene, species of the megaherbivorous sirenian Hydrodamalis ranged throughout North Pacific giant kelp forests. The last species, H. gigas, was driven to extinction by human hunting in the mid-eighteen century. H. gigas was an obligate kelp canopy browser, and its body size implies that it would have had a significant impact on the system. Here, we hypothesize that sea cow browsing may have enhanced forest resilience. We tested this hypothesis with a mathematical model, comparing historical and modern community responses to marine heat waves and sea star wasting disease. Results indicate that forest communities were highly resistant to marine heat waves, yet susceptible to sea star wasting disease, and to disease in combination with warming. Resistance was greatest among systems with both sea cows and sea otters present. The model additionally predicts that historical communities may have exhibited delayed transitions after perturbation and faster recovery times. Sea cow browsing may therefore have enhanced resilience against modern perturbations. We propose that operationalizing these findings by mimicking sea cow herbivory could enhance kelp forest resilience.
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7
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Allen AG, Roehrs ZP, Seville RS, Lanier HC. Competitive release during fire succession influences ecological turnover in a small mammal community. Ecology 2022; 103:e3733. [PMID: 35430726 PMCID: PMC9891167 DOI: 10.1002/ecy.3733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 02/25/2022] [Accepted: 03/01/2022] [Indexed: 02/03/2023]
Abstract
Ecologists have long debated the relative importance of biotic interactions versus species-specific habitat preferences in shaping patterns of ecological dominance. In western North America, cycles of fire disturbance are marked by transitions between North American deermice (Peromyscus maniculatus), which predominate after wildfires, and southern red-backed voles (Myodes gapperi), which gradually replace deermice 3-4 years postfire and maintain dominance as forests mature. While this shift has been frequently documented, the processes that mediate this turnover are debated. One possibility is competitive release, which predicts a reduction in vole competition may contribute to niche expansion and population growth in deermice. Alternatively, turnover in both species may be shaped by differences in their preferred habitat and resource base, as predicted by optimum foraging theory. We evaluate these hypotheses using stable isotopes and spatial mark-recapture of deermouse and vole populations sampled prior to and following a fire as part of a longitudinal study in the Greater Yellowstone Ecosystem. Fire disturbance was associated with a 94% decrease in vole abundance but a 102% increase in deermice. Even after accounting for microhabitat, vole and deermouse populations were negatively correlated spatially and temporally (R = -0.45), and competitor abundance was more important prefire than postfire. When vole abundance was high (prefire), vole dietary niche space was seven times broader than that of deermice. Postfire, deermouse dietary niche nearly tripled and was enriched in 13 C (i.e., more C4 plants), while voles occupied a slightly reduced dietary niche (79% of prefire breadth). Our results suggest deermice are experiencing ecological release due to a reduction in vole competition but vole shifts are largely driven by habitat preferences.
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Affiliation(s)
| | - Zachary P. Roehrs
- School of Math and Sciences, Laramie County Community College, Cheyenne, WY 82007 USA
| | - R. Scott Seville
- Department of Zoology and Physiology, University of Wyoming at Casper, Casper, WY 82601 USA
| | - Hayley C. Lanier
- Department of Biology and Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, OK 73072 USA
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8
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Reply to: "Steller's sea cow uncertain history illustrates importance of ecological context when interpreting demographic histories from genomes". Nat Commun 2022; 13:3672. [PMID: 35764648 PMCID: PMC9240042 DOI: 10.1038/s41467-022-31382-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 06/14/2022] [Indexed: 11/15/2022] Open
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9
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Le Duc D, Velluva A, Cassatt-Johnstone M, Olsen RA, Baleka S, Lin CC, Lemke JR, Southon JR, Burdin A, Wang MS, Grunewald S, Rosendahl W, Joger U, Rutschmann S, Hildebrandt TB, Fritsch G, Estes JA, Kelso J, Dalén L, Hofreiter M, Shapiro B, Schöneberg T. Genomic basis for skin phenotype and cold adaptation in the extinct Steller's sea cow. SCIENCE ADVANCES 2022; 8:eabl6496. [PMID: 35119923 PMCID: PMC8816345 DOI: 10.1126/sciadv.abl6496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Steller's sea cow, an extinct sirenian and one of the largest Quaternary mammals, was described by Georg Steller in 1741 and eradicated by humans within 27 years. Here, we complement Steller's descriptions with paleogenomic data from 12 individuals. We identified convergent evolution between Steller's sea cow and cetaceans but not extant sirenians, suggesting a role of several genes in adaptation to cold aquatic (or marine) environments. Among these are inactivations of lipoxygenase genes, which in humans and mouse models cause ichthyosis, a skin disease characterized by a thick, hyperkeratotic epidermis that recapitulates Steller's sea cows' reportedly bark-like skin. We also found that Steller's sea cows' abundance was continuously declining for tens of thousands of years before their description, implying that environmental changes also contributed to their extinction.
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Affiliation(s)
- Diana Le Duc
- Institute of Human Genetics, University Medical Center Leipzig, 04103 Leipzig, Germany
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Akhil Velluva
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Molly Cassatt-Johnstone
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Remi-Andre Olsen
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Box 1031 , SE-17121 Solna, Sweden
| | - Sina Baleka
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
- Faculty of Life and Environmental Sciences, University of Iceland, 102 Reykjavik, Iceland
| | - Chen-Ching Lin
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, 11221 Taipei, Taiwan
| | - Johannes R. Lemke
- Institute of Human Genetics, University Medical Center Leipzig, 04103 Leipzig, Germany
| | - John R. Southon
- Keck-CCAMS Group, Earth System Science Department, University of California, Irvine, Irvine, CA 92697, USA
| | - Alexander Burdin
- Kamchatka Branch of Pacific Geographical Institute, Russian Academy of Science, 683000 Petropavlovsk-Kamchatsky, Russia
| | - Ming-Shan Wang
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
- Howard Hughes Medical Institute, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Sonja Grunewald
- Department of Dermatology, Venerology and Allergology, University Medical Center Leipzig, 04103 Leipzig, Germany
| | - Wilfried Rosendahl
- Reiss-Engelhorn-Museum and Curt-Engelhorn-Centre of Archaeometry, 68159 Mannheim, Germany
| | - Ulrich Joger
- State Museum of Natural History, 38106 Braunschweig, Germany
| | - Sereina Rutschmann
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| | - Thomas B. Hildebrandt
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
- Faculty of Veterinary Medicine, Free University Berlin, 14195 Berlin, Germany
| | - Guido Fritsch
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - James A. Estes
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Love Dalén
- Centre for Palaeogenetics, SE-106 91 Stockholm, Sweden
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, SE-104 05 Stockholm, Sweden
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Michael Hofreiter
- Evolutionary Adaptive Genomics, Institute for Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| | - Beth Shapiro
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
- Howard Hughes Medical Institute, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
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10
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Sharko FS, Boulygina ES, Tsygankova SV, Slobodova NV, Alekseev DA, Krasivskaya AA, Rastorguev SM, Tikhonov AN, Nedoluzhko AV. Steller's sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans. Nat Commun 2021; 12:2215. [PMID: 33850161 PMCID: PMC8044168 DOI: 10.1038/s41467-021-22567-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 03/11/2021] [Indexed: 12/28/2022] Open
Abstract
Anthropogenic activity is the top factor directly related to the extinction of several animal species. The last Steller's sea cow (Hydrodamalis gigas) population on the Commander Islands (Russia) was wiped out in the second half of the 18th century due to sailors and fur traders hunting it for the meat and fat. However, new data suggests that the extinction process of this species began much earlier. Here, we present a nuclear de novo assembled genome of H. gigas with a 25.4× depth coverage. Our results demonstrate that the heterozygosity of the last population of this animal is low and comparable to the last woolly mammoth population that inhabited Wrangel Island 4000 years ago. Besides, as a matter of consideration, our findings also demonstrate that the extinction of this marine mammal starts along the North Pacific coastal line much earlier than the first Paleolithic humans arrived in the Bering sea region.
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Affiliation(s)
- Fedor S Sharko
- National Research Center "Kurchatov Institute", 1st Akademika Kurchatova Square, Moscow, Russia.,Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Eugenia S Boulygina
- National Research Center "Kurchatov Institute", 1st Akademika Kurchatova Square, Moscow, Russia
| | - Svetlana V Tsygankova
- National Research Center "Kurchatov Institute", 1st Akademika Kurchatova Square, Moscow, Russia
| | - Natalia V Slobodova
- National Research Center "Kurchatov Institute", 1st Akademika Kurchatova Square, Moscow, Russia
| | - Dmitry A Alekseev
- Russian Presidential Academy of National Economy and Public Administration, Prospect Vernadskogo, 82, Moscow, Russia
| | | | - Sergey M Rastorguev
- National Research Center "Kurchatov Institute", 1st Akademika Kurchatova Square, Moscow, Russia
| | - Alexei N Tikhonov
- Zoological Institute Russian Academy of Sciences, Universitetskaya nab., 1, Saint-Petersburg, Russia.,Institute of Applied Ecology of the North, North-Eastern Federal University, Yakutsk, Russia
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11
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McPherson ML, Finger DJI, Houskeeper HF, Bell TW, Carr MH, Rogers-Bennett L, Kudela RM. Large-scale shift in the structure of a kelp forest ecosystem co-occurs with an epizootic and marine heatwave. Commun Biol 2021; 4:298. [PMID: 33674760 PMCID: PMC7935997 DOI: 10.1038/s42003-021-01827-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/09/2021] [Indexed: 01/31/2023] Open
Abstract
Climate change is responsible for increased frequency, intensity, and duration of extreme events, such as marine heatwaves (MHWs). Within eastern boundary current systems, MHWs have profound impacts on temperature-nutrient dynamics that drive primary productivity. Bull kelp (Nereocystis luetkeana) forests, a vital nearshore habitat, experienced unprecedented losses along 350 km of coastline in northern California beginning in 2014 and continuing through 2019. These losses have had devastating consequences to northern California communities, economies, and fisheries. Using a suite of in situ and satellite-derived data, we demonstrate that the abrupt ecosystem shift initiated by a multi-year MHW was preceded by declines in keystone predator population densities. We show strong evidence that northern California kelp forests, while temporally dynamic, were historically resilient to fluctuating environmental conditions, even in the absence of key top predators, but that a series of coupled environmental and biological shifts between 2014 and 2016 resulted in the formation of a persistent, altered ecosystem state with low primary productivity. Based on our findings, we recommend the implementation of ecosystem-based and adaptive management strategies, such as (1) monitoring the status of key ecosystem attributes: kelp distribution and abundance, and densities of sea urchins and their predators, (2) developing management responses to threshold levels of these attributes, and (3) creating quantitative restoration suitability indices for informing kelp restoration efforts.
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Affiliation(s)
- Meredith L McPherson
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA.
| | - Dennis J I Finger
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, USA
| | - Henry F Houskeeper
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Geography, University of California Los Angeles, Los Angeles, CA, USA
| | - Tom W Bell
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Earth Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Mark H Carr
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Laura Rogers-Bennett
- Coastal Marine Science Institute, Karen C. Drayer Wildlife Health Center, University of California Davis and California Department of Fish and Wildlife, Bodega Marine Laboratory, Bodega Bay, CA, USA
| | - Raphael M Kudela
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
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12
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Whitham TG, Allan GJ, Cooper HF, Shuster SM. Intraspecific Genetic Variation and Species Interactions Contribute to Community Evolution. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2020. [DOI: 10.1146/annurev-ecolsys-011720-123655] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Evolution has been viewed as occurring primarily through selection among individuals. We present a framework based on multilevel selection for evaluating evolutionary change from individuals to communities, with supporting empirical evidence. Essential to this evaluation is the role that interspecific indirect genetic effects play in shaping community organization, in generating variation among community phenotypes, and in creating community heritability. If communities vary in phenotype, and those phenotypes are heritable and subject to selection at multiple levels, then a community view of evolution must be merged with mainstream evolutionary theory. Rapid environmental change during the Anthropocene will require a better understanding of these evolutionary processes, especially selection acting at the community level, which has the potential to eliminate whole communities while favoring others.
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Affiliation(s)
- Thomas G. Whitham
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Gerard J. Allan
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Hillary F. Cooper
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Stephen M. Shuster
- Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, Arizona 86011, USA
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13
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Morrison BML, Dirzo R. Distinct responses of antagonistic and mutualistic networks to agricultural intensification. Ecology 2020; 101:e03116. [PMID: 32530504 DOI: 10.1002/ecy.3116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/18/2020] [Accepted: 05/04/2020] [Indexed: 11/08/2022]
Abstract
Species interaction networks, which govern the maintenance of biodiversity and ecosystem processes within ecological communities, are being rapidly altered by anthropogenic activities worldwide. Studies on the response of species interaction networks to anthropogenic disturbance have almost exclusively focused on one interaction type at a time, such as mutualistic or antagonistic interactions, making it challenging to decipher how networks of different interaction types respond to the same anthropogenic disturbance. Moreover, few studies have simultaneously focused on the two main components of network structure: network topology (i.e., architecture) and network ecology (i.e., species identities and interaction turnover), thereby limiting our understanding of the ecological drivers underlying changes in network topology in response to anthropogenic disturbance. Here, we used 16,400 plant-pollinator and plant-herbivore interaction observations from 16 sites along an agricultural intensification gradient to compare changes in network topology and ecology between mutualistic and antagonistic networks. We measured two aspects of network topology-nestedness and modularity-and found that although the mutualistic networks were consistently more nested than antagonistic networks and antagonistic networks were consistently more modular, the rate of change in nestedness and modularity along the gradient was comparable between the two network types. Change in network ecology, however, was distinct between mutualistic and antagonistic networks, with partner switching making a significantly larger contribution to interaction turnover in the mutualistic networks than in the antagonistic networks, and species turnover being a strong contributor to interaction turnover in the antagonistic networks. The ecological and topological changes we observed in the antagonistic and mutualistic networks have different implications for pollinator and herbivore communities in agricultural landscapes, and support the idea that pollinators are more labile in their interaction partner choice, whereas herbivores form more reciprocally specialized, and therefore more vulnerable, interactions. Our results also demonstrate that studying both topological and ecological network structure can help to elucidate the effects of anthropogenic disturbance on ecological communities, with applications for conservation and restoration of species interactions and the ecosystem processes they maintain.
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Affiliation(s)
- Beth M L Morrison
- Department of Biology, Stanford University, Stanford, California, 94305, USA
| | - Rodolfo Dirzo
- Department of Biology, Stanford University, Stanford, California, 94305, USA
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14
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Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction. Proc Natl Acad Sci U S A 2020; 117:13596-13602. [PMID: 32482862 PMCID: PMC7306750 DOI: 10.1073/pnas.1922686117] [Citation(s) in RCA: 199] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The ongoing sixth mass extinction may be the most serious environmental threat to the persistence of civilization, because it is irreversible. Thousands of populations of critically endangered vertebrate animal species have been lost in a century, indicating that the sixth mass extinction is human caused and accelerating. The acceleration of the extinction crisis is certain because of the still fast growth in human numbers and consumption rates. In addition, species are links in ecosystems, and, as they fall out, the species they interact with are likely to go also. In the regions where disappearing species are concentrated, regional biodiversity collapses are likely occurring. Our results reemphasize the extreme urgency of taking massive global actions to save humanity’s crucial life-support systems. The ongoing sixth mass species extinction is the result of the destruction of component populations leading to eventual extirpation of entire species. Populations and species extinctions have severe implications for society through the degradation of ecosystem services. Here we assess the extinction crisis from a different perspective. We examine 29,400 species of terrestrial vertebrates, and determine which are on the brink of extinction because they have fewer than 1,000 individuals. There are 515 species on the brink (1.7% of the evaluated vertebrates). Around 94% of the populations of 77 mammal and bird species on the brink have been lost in the last century. Assuming all species on the brink have similar trends, more than 237,000 populations of those species have vanished since 1900. We conclude the human-caused sixth mass extinction is likely accelerating for several reasons. First, many of the species that have been driven to the brink will likely become extinct soon. Second, the distribution of those species highly coincides with hundreds of other endangered species, surviving in regions with high human impacts, suggesting ongoing regional biodiversity collapses. Third, close ecological interactions of species on the brink tend to move other species toward annihilation when they disappear—extinction breeds extinctions. Finally, human pressures on the biosphere are growing rapidly, and a recent example is the current coronavirus disease 2019 (Covid-19) pandemic, linked to wildlife trade. Our results reemphasize the extreme urgency of taking much-expanded worldwide actions to save wild species and humanity’s crucial life-support systems from this existential threat.
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15
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Pimiento C, Leprieur F, Silvestro D, Lefcheck JS, Albouy C, Rasher DB, Davis M, Svenning JC, Griffin JN. Functional diversity of marine megafauna in the Anthropocene. SCIENCE ADVANCES 2020; 6:eaay7650. [PMID: 32494601 PMCID: PMC7164949 DOI: 10.1126/sciadv.aay7650] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 01/13/2020] [Indexed: 05/10/2023]
Abstract
Marine megafauna, the largest animals in the oceans, serve key roles in ecosystem functioning. Yet, one-third of these animals are at risk of extinction. To better understand the potential consequences of megafaunal loss, here we quantify their current functional diversity, predict future changes under different extinction scenarios, and introduce a new metric [functionally unique, specialized and endangered (FUSE)] that identifies threatened species of particular importance for functional diversity. Simulated extinction scenarios forecast marked declines in functional richness if current trajectories are maintained during the next century (11% globally; up to 24% regionally), with more marked reductions (48% globally; up to 70% at the poles) beyond random expectations if all threatened species eventually go extinct. Among the megafaunal groups, sharks will incur a disproportionate loss of functional richness. We identify top FUSE species and suggest a renewed focus on these species to preserve the ecosystem functions provided by marine megafauna.
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Affiliation(s)
- C. Pimiento
- Department of Biosciences, Swansea University, Wallace Building, Singleton Park, Swansea SA2 8PP, UK
- Smithsonian Tropical Research Institute, Box 2072, Balboa, Panama
- Corresponding author.
| | - F. Leprieur
- MARBEC, Université de Montpellier, CNRS, Ifremer, IRD, Montpellier, France
- Institut Universitaire de France (IUF), Paris, France
| | - D. Silvestro
- Department of Biological and Environmental Sciences, University of Gothenburg and Global Gothenburg Biodiversity Centre, 41319 Gothenburg, Sweden
- Department of Computational Biology, University of Lausanne, Lausanne 1015, Switzerland
| | - J. S. Lefcheck
- Tennenbaum Marine Observatories Network, MarineGEO, Smithsonian Environmental Research Center, Edgewater, MD 21037, USA
| | - C. Albouy
- IFREMER, Unité Ecologie et Modèles pour l’Halieutique, Nantes Cedex 3, France
| | - D. B. Rasher
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, ME 04544, USA
| | - M. Davis
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE) and Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
- Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007, USA
| | - J.-C. Svenning
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE) and Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - J. N. Griffin
- Department of Biosciences, Swansea University, Wallace Building, Singleton Park, Swansea SA2 8PP, UK
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16
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Nair RR, Vasse M, Wielgoss S, Sun L, Yu YTN, Velicer GJ. Bacterial predator-prey coevolution accelerates genome evolution and selects on virulence-associated prey defences. Nat Commun 2019; 10:4301. [PMID: 31541093 PMCID: PMC6754418 DOI: 10.1038/s41467-019-12140-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 08/22/2019] [Indexed: 01/08/2023] Open
Abstract
Generalist bacterial predators are likely to strongly shape many important ecological and evolutionary features of microbial communities, for example by altering the character and pace of molecular evolution, but investigations of such effects are scarce. Here we report how predator-prey interactions alter the evolution of fitness, genomes and phenotypic diversity in coevolving bacterial communities composed of Myxococcus xanthus as predator and Escherichia coli as prey, relative to single-species controls. We show evidence of reciprocal adaptation and demonstrate accelerated genomic evolution specific to coevolving communities, including the rapid appearance of mutator genotypes. Strong parallel evolution unique to the predator-prey communities occurs in both parties, with predators driving adaptation at two prey traits associated with virulence in bacterial pathogens-mucoidy and the outer-membrane protease OmpT. Our results suggest that generalist predatory bacteria are important determinants of how complex microbial communities and their interaction networks evolve in natural habitats.
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Affiliation(s)
- Ramith R Nair
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland.
| | - Marie Vasse
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland.
| | - Sébastien Wielgoss
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
| | - Lei Sun
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
- Department of Systems Biology, Harvard Medical School, 02115, Boston, MA, USA
| | - Yuen-Tsu N Yu
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
| | - Gregory J Velicer
- Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland
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17
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Yorke CE, Page HM, Miller RJ. Sea urchins mediate the availability of kelp detritus to benthic consumers. Proc Biol Sci 2019; 286:20190846. [PMID: 31288702 PMCID: PMC6650708 DOI: 10.1098/rspb.2019.0846] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 06/19/2019] [Indexed: 11/12/2022] Open
Abstract
Detritus can fundamentally shape and sustain food webs, and shredders can facilitate its availability. Most of the biomass of the highly productive giant kelp, Macrocystis pyrifera, becomes detritus that is exported or falls to the seafloor as litter. We hypothesized that sea urchins process kelp litter through shredding, sloppy feeding and egestion, making kelp litter more available to benthic consumers. To test this, we conducted a mesocosm experiment in which an array of kelp forest benthic consumers were exposed to 13C- and 15N-labelled Macrocystis with or without the presence of sea urchins, Strongylocentrotus purpuratus. Our results showed that several detritivore species consumed significant amounts of kelp, but only when urchins were present. Although they are typically portrayed as antagonistic grazers in kelp forests, sea urchins can have a positive trophic role, capturing kelp litter before it is exported and making it available to a suite of benthic detritivores.
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Affiliation(s)
- Christie E. Yorke
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106-9620, USA
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18
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Starko S, Soto Gomez M, Darby H, Demes KW, Kawai H, Yotsukura N, Lindstrom SC, Keeling PJ, Graham SW, Martone PT. A comprehensive kelp phylogeny sheds light on the evolution of an ecosystem. Mol Phylogenet Evol 2019; 136:138-150. [PMID: 30980936 DOI: 10.1016/j.ympev.2019.04.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/24/2022]
Abstract
Reconstructing phylogenetic topologies and divergence times is essential for inferring the timing of radiations, the appearance of adaptations, and the historical biogeography of key lineages. In temperate marine ecosystems, kelps (Laminariales) drive productivity and form essential habitat but an incomplete understanding of their phylogeny has limited our ability to infer their evolutionary origins and the spatial and temporal patterns of their diversification. Here, we reconstruct the diversification of habitat-forming kelps using a global genus-level phylogeny inferred primarily from organellar genome datasets, and investigate the timing of kelp radiation. We resolve several important phylogenetic features, including relationships among the morphologically simple kelp families and the broader radiation of complex kelps, demonstrating that the initial radiation of the latter resulted from an increase in speciation rate around the Eocene-Oligocene boundary. This burst in speciation rate is consistent with a possible role of recent climatic cooling in triggering the kelp radiation and pre-dates the origin of benthic-foraging carnivores. Historical biogeographical reconstructions point to a northeast Pacific origin of complex kelps, with subsequent colonization of new habitats likely playing an important role in driving their ecological diversification. We infer that complex morphologies associated with modern kelp forests (e.g. branching, pneumatocysts) evolved several times over the past 15-20 MY, highlighting the importance of morphological convergence in establishing modern upright kelp forests. Our phylogenomic findings provide new insights into the geographical and ecological proliferation of kelps and provide a timeline along which feedbacks between kelps and their food-webs could have shaped the structure of temperate ecosystems.
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Affiliation(s)
- Samuel Starko
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada; Bamfield Marine Sciences Centre, 100 Pachena Rd., Bamfield V0R 1B0, Canada; Hakai Institute, Heriot Bay, Quadra Island, Canada.
| | - Marybel Soto Gomez
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Hayley Darby
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Kyle W Demes
- Department of Zoology, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Hiroshi Kawai
- Department of Biology, Kobe University, Rokkodaicho 657-8501, Japan
| | - Norishige Yotsukura
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo 060-0809, Japan
| | - Sandra C Lindstrom
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Patrick J Keeling
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada; Department of Zoology, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Sean W Graham
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada
| | - Patrick T Martone
- Department of Botany & Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd., Vancouver V6T 1Z4, Canada; Bamfield Marine Sciences Centre, 100 Pachena Rd., Bamfield V0R 1B0, Canada; Hakai Institute, Heriot Bay, Quadra Island, Canada
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19
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Littles CJ, Bonde RK, Butler SM, Jacoby CA, Notestein SK, Reid JP, Slone DH, Frazer TK. COASTAL HABITAT CHANGE AND MARINE MEGAFAUNA BEHAVIOR: FLORIDA MANATEES ENCOUNTERING REDUCED FOOD PROVISIONS IN A PROMINENT WINTER REFUGE. ENDANGER SPECIES RES 2019; 38:29-43. [PMID: 31105796 DOI: 10.3354/esr00933] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A decline in submerged aquatic vegetation (SAV) within Florida's spring-fed, thermal refuges raises questions about how these systems support winter foraging of Florida manatees (Trichechus manatus latirostris). We analyzed telemetry data for 12 manatees over seven years to assess their use of Kings Bay, a winter refuge with diminished SAV. After accounting for the effect of water temperature, we hypothesized that the number of trips out of Kings Bay would increase and the time wintering manatees spent in Kings Bay would decrease. Trips out of and into Kings Bay also were compared to assess potential influences on exiting or entering. There were no detectable differences in the number of trips out of the bay or overall time manatees spent in Kings Bay across winters. The percentage of time water temperatures were below 20°C was the single best predictor of increased time spent in Kings Bay. Trips out of Kings Bay were more likely to occur after 12:00 h and during a high but ebbing tide, compared to trips into the bay. Nine manatees tracked for longer than 75 days in winter spent 7-57% of their time in the Gulf of Mexico, and three of these manatees spent 7-65% of the winter >80 km from the mouth of Kings Bay. Results suggest the low amount of SAV in Kings Bay does not obviate its use by manatees, though there are likely tradeoffs for manatees regularly foraging elsewhere. Accounting for movements of Florida manatees through a network of habitats may improve management strategies and facilitate desirable conservation outcomes.
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Affiliation(s)
- Chanda J Littles
- School of Natural Resources and Environment, University of Florida, Gainesville, FL 32611, USA
| | - Robert K Bonde
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL 32653, USA
| | - Susan M Butler
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL 32653, USA
| | - Charles A Jacoby
- Soil and Water Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Sky K Notestein
- Southwest Florida Water Management District, Brooksville, FL 34606, USA
| | - James P Reid
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL 32653, USA
| | - Daniel H Slone
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL 32653, USA
| | - Thomas K Frazer
- School of Natural Resources and Environment, University of Florida, Gainesville, FL 32611, USA
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20
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Ecosystem Function and Services of Aquatic Predators in the Anthropocene. Trends Ecol Evol 2019; 34:369-383. [PMID: 30857757 DOI: 10.1016/j.tree.2019.01.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 01/17/2019] [Accepted: 01/18/2019] [Indexed: 11/23/2022]
Abstract
Arguments for the need to conserve aquatic predator (AP) populations often focus on the ecological and socioeconomic roles they play. Here, we summarize the diverse ecosystem functions and services connected to APs, including regulating food webs, cycling nutrients, engineering habitats, transmitting diseases/parasites, mediating ecological invasions, affecting climate, supporting fisheries, generating tourism, and providing bioinspiration. In some cases, human-driven declines and increases in AP populations have altered these ecosystem functions and services. We present a social ecological framework for supporting adaptive management decisions involving APs in response to social and environmental change. We also identify outstanding questions to guide future research on the ecological functions and ecosystem services of APs in a changing world.
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21
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Schweiger AH, Boulangeat I, Conradi T, Davis M, Svenning JC. The importance of ecological memory for trophic rewilding as an ecosystem restoration approach. Biol Rev Camb Philos Soc 2019; 94:1-15. [PMID: 29877019 DOI: 10.1111/brv.12432] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 05/05/2018] [Accepted: 05/14/2018] [Indexed: 01/24/2023]
Abstract
Increasing human pressure on strongly defaunated ecosystems is characteristic of the Anthropocene and calls for proactive restoration approaches that promote self-sustaining, functioning ecosystems. However, the suitability of novel restoration concepts such as trophic rewilding is still under discussion given fragmentary empirical data and limited theory development. Here, we develop a theoretical framework that integrates the concept of 'ecological memory' into trophic rewilding. The ecological memory of an ecosystem is defined as an ecosystem's accumulated abiotic and biotic material and information legacies from past dynamics. By summarising existing knowledge about the ecological effects of megafauna extinction and rewilding across a large range of spatial and temporal scales, we identify two key drivers of ecosystem responses to trophic rewilding: (i) impact potential of (re)introduced megafauna, and (ii) ecological memory characterising the focal ecosystem. The impact potential of (re)introduced megafauna species can be estimated from species properties such as lifetime per capita engineering capacity, population density, home range size and niche overlap with resident species. The importance of ecological memory characterising the focal ecosystem depends on (i) the absolute time since megafauna loss, (ii) the speed of abiotic and biotic turnover, (iii) the strength of species interactions characterising the focal ecosystem, and (iv) the compensatory capacity of surrounding source ecosystems. These properties related to the focal and surrounding ecosystems mediate material and information legacies (its ecological memory) and modulate the net ecosystem impact of (re)introduced megafauna species. We provide practical advice about how to quantify all these properties while highlighting the strong link between ecological memory and historically contingent ecosystem trajectories. With this newly established ecological memory-rewilding framework, we hope to guide future empirical studies that investigate the ecological effects of trophic rewilding and other ecosystem-restoration approaches. The proposed integrated conceptual framework should also assist managers and decision makers to anticipate the possible trajectories of ecosystem dynamics after restoration actions and to weigh plausible alternatives. This will help practitioners to develop adaptive management strategies for trophic rewilding that could facilitate sustainable management of functioning ecosystems in an increasingly human-dominated world.
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Affiliation(s)
- Andreas H Schweiger
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.,Plant Ecology, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany.,Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark
| | - Isabelle Boulangeat
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.,University Grenoble Alpes, Irstea, UR LESSEM, 2 rue de la Papeterie-BP 76, F-38402, St-Martin-d'Hères, France
| | - Timo Conradi
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.,Plant Ecology, Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440, Bayreuth, Germany
| | - Matt Davis
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.,Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark
| | - Jens-Christian Svenning
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.,Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark
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22
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Mann DH, Groves P, Gaglioti BV, Shapiro BA. Climate-driven ecological stability as a globally shared cause of Late Quaternary megafaunal extinctions: the Plaids and Stripes Hypothesis. Biol Rev Camb Philos Soc 2019; 94:328-352. [PMID: 30136433 PMCID: PMC7379602 DOI: 10.1111/brv.12456] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 07/14/2018] [Accepted: 07/19/2018] [Indexed: 01/24/2023]
Abstract
Controversy persists about why so many large-bodied mammal species went extinct around the end of the last ice age. Resolving this is important for understanding extinction processes in general, for assessing the ecological roles of humans, and for conserving remaining megafaunal species, many of which are endangered today. Here we explore an integrative hypothesis that asserts that an underlying cause of Late Quaternary megafaunal extinctions was a fundamental shift in the spatio-temporal fabric of ecosystems worldwide. This shift was triggered by the loss of the millennial-scale climate fluctuations that were characteristic of the ice age but ceased approximately 11700 years ago on most continents. Under ice-age conditions, which prevailed for much of the preceding 2.6 Ma, these radical and rapid climate changes prevented many ecosystems from fully equilibrating with their contemporary climates. Instead of today's 'striped' world in which species' ranges have equilibrated with gradients of temperature, moisture, and seasonality, the ice-age world was a disequilibrial 'plaid' in which species' ranges shifted rapidly and repeatedly over time and space, rarely catching up with contemporary climate. In the transient ecosystems that resulted, certain physiological, anatomical, and ecological attributes shared by megafaunal species pre-adapted them for success. These traits included greater metabolic and locomotory efficiency, increased resistance to starvation, longer life spans, greater sensory ranges, and the ability to be nomadic or migratory. When the plaid world of the ice age ended, many of the advantages of being large were either lost or became disadvantages. For instance in a striped world, the low population densities and slow reproductive rates associated with large body size reduced the resiliency of megafaunal species to population bottlenecks. As the ice age ended, the downsides of being large in striped environments lowered the extinction thresholds of megafauna worldwide, which then increased the vulnerability of individual species to a variety of proximate threats they had previously tolerated, such as human predation, competition with other species, and habitat loss. For many megafaunal species, the plaid-to-stripes transition may have been near the base of a hierarchy of extinction causes whose relative importances varied geographically, temporally, and taxonomically.
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Affiliation(s)
- Daniel H. Mann
- Department of Geosciences and Institute of Arctic BiologyUniversity of AlaskaFairbanksAK 99775USA
| | - Pamela Groves
- Institute of Arctic BiologyUniversity of AlaskaFairbanksAK 99775USA
| | | | - Beth A. Shapiro
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaSanta CruzCA 95064USA
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23
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Valdivia A, Wolf S, Suckling K. Marine mammals and sea turtles listed under the U.S. Endangered Species Act are recovering. PLoS One 2019; 14:e0210164. [PMID: 30650125 PMCID: PMC6334928 DOI: 10.1371/journal.pone.0210164] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 12/18/2018] [Indexed: 11/24/2022] Open
Abstract
The U.S. Endangered Species Act (ESA) is a powerful environmental law protecting imperiled plants and animals, and a growing number of marine species have been protected under this law as extinction risk in the oceans has increased. Marine mammals and sea turtles comprise 38% of the 163 ESA-listed marine "species", which includes subspecies and distinct population segments, yet analyses of recovery trends after listing are lacking. Here we gathered the best available annual abundance estimates for geographically delimited populations of all 62 marine mammal and sea turtle species listed under the ESA. Of these, we chose representative populations of species that were listed before 2012, occur and reproduce in U.S. waters, and have data of sufficient quality and timespan for trend analyses. Thus, we quantitatively analyzed population trends, magnitude of population change, and recovery status for 23 and 8 representative populations of 14 marine mammal and 5 sea turtle species, respectively. Using generalized linear and non-linear models, we found that 18 marine mammal (78%) and 6 sea turtle (75%) populations significantly increased after listing; 3 marine mammal (13%) and 2 sea turtle (25%) populations showed non-significant changes; while 2 marine mammal (9%), but no sea turtle populations declined after ESA protection. Overall, the 24 populations that increased in abundance were from species listed for 20 years or more (e.g., large whales, manatees, and sea turtles). Conservation measures triggered by ESA listing such as ending exploitation, tailored species management, and fishery regulations, and other national and international measures, appear to have been largely successful in promoting species recovery, leading to the delisting of some species and to increases in most populations. These findings underscore the capacity of marine mammal and sea turtle species to recover from substantial geographical population declines when conservation actions are implemented in a timely and effective manner.
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Affiliation(s)
- Abel Valdivia
- Center for Biological Diversity, Oakland, California, United States of America
| | - Shaye Wolf
- Center for Biological Diversity, Oakland, California, United States of America
| | - Kieran Suckling
- Center for Biological Diversity, Tucson, Arizona, United States of America
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24
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Absence of native flower visitors for the endangered Hawaiian mint Stenogyne angustifolia: Impending ecological extinction? Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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25
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Cirtwill AR, Dalla Riva GV, Gaiarsa MP, Bimler MD, Cagua EF, Coux C, Dehling DM. A review of species role concepts in food webs. FOOD WEBS 2018. [DOI: 10.1016/j.fooweb.2018.e00093] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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26
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Donohue I, Petchey OL, Kéfi S, Génin A, Jackson AL, Yang Q, O'Connor NE. Loss of predator species, not intermediate consumers, triggers rapid and dramatic extinction cascades. GLOBAL CHANGE BIOLOGY 2017; 23:2962-2972. [PMID: 28346736 DOI: 10.1111/gcb.13703] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/23/2017] [Accepted: 03/09/2017] [Indexed: 06/06/2023]
Abstract
Ecological networks are tightly interconnected, such that loss of a single species can trigger additional species extinctions. Theory predicts that such secondary extinctions are driven primarily by loss of species from intermediate or basal trophic levels. In contrast, most cases of secondary extinctions from natural systems have been attributed to loss of entire top trophic levels. Here, we show that loss of single predator species in isolation can, irrespective of their identity or the presence of other predators, trigger rapid secondary extinction cascades in natural communities far exceeding those generally predicted by theory. In contrast, we did not find any secondary extinctions caused by intermediate consumer loss. A food web model of our experimental system-a marine rocky shore community-could reproduce these results only when biologically likely and plausible nontrophic interactions, based on competition for space and predator-avoidance behaviour, were included. These findings call for a reassessment of the scale and nature of extinction cascades, particularly the inclusion of nontrophic interactions, in forecasts of the future of biodiversity.
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Affiliation(s)
- Ian Donohue
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - Owen L Petchey
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Sonia Kéfi
- CNRS, IRD, EPHE, CC065, Institut des Sciences de l'Evolution, BioDICée team, Université de Montpellier, Montpellier, France
| | - Alexandre Génin
- CNRS, IRD, EPHE, CC065, Institut des Sciences de l'Evolution, BioDICée team, Université de Montpellier, Montpellier, France
| | - Andrew L Jackson
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - Qiang Yang
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - Nessa E O'Connor
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
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27
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Young HS, McCauley DJ, Galetti M, Dirzo R. Patterns, Causes, and Consequences of Anthropocene Defaunation. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2016. [DOI: 10.1146/annurev-ecolsys-112414-054142] [Citation(s) in RCA: 233] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Anthropocene defaunation, the global extinction of faunal species and populations and the decline in abundance of individuals within populations, has been predominantly documented in terrestrial ecosystems, but indicators suggest defaunation has been more severe in freshwater ecosystems. Marine defaunation is in a more incipient stage, yet pronounced effects are already apparent and its rapid acceleration seems likely. Defaunation now impacts the planet's wildlife with profound cascading consequences, ranging from local to global coextinctions of interacting species to the loss of ecological services critical for humanity. Slowing defaunation will require aggressively reducing animal overexploitation and habitat destruction; mitigating climate disruption; and stabilizing the impacts of human population growth and uneven resource consumption. Given its omnipresence, defaunation should receive status of major global environmental change and should be addressed with the same urgency as deforestation, pollution, and climatic change. Global action is needed to prevent defaunation's current trajectory from catalyzing the planet's sixth major extinction.
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Affiliation(s)
- Hillary S. Young
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106
| | - Douglas J. McCauley
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106
| | - Mauro Galetti
- Departamento de Ecologia, Universidade Estadual Paulista (UNESP), 13506–900 Rio Claro, São Paulo, Brazil
| | - Rodolfo Dirzo
- Department of Biology, Stanford University, Stanford, California 94305
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28
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McCauley DJ, Hardesty‐Moore M, Halpern BS, Young HS. A mammoth undertaking: harnessing insight from functional ecology to shape de‐extinction priority setting. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12728] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Douglas J. McCauley
- Department of Ecology, Evolution, and Marine Biology University of California Santa Barbara CA93106 USA
| | - Molly Hardesty‐Moore
- Department of Ecology, Evolution, and Marine Biology University of California Santa Barbara CA93106 USA
| | - Benjamin S. Halpern
- Bren School of Environmental Science & Management University of California Santa Barbara CA93106 USA
- National Center for Ecological Analysis and Synthesis University of California 735 State St. Suite 300 Santa Barbara CA93101 USA
- Imperial College London Silwood Park Campus Buckhurst Rd AscotSL57PY UK
| | - Hillary S. Young
- Department of Ecology, Evolution, and Marine Biology University of California Santa Barbara CA93106 USA
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Abstract
Large herbivores and carnivores (the megafauna) have been in a state of decline and extinction since the Late Pleistocene, both on land and more recently in the oceans. Much has been written on the timing and causes of these declines, but only recently has scientific attention focused on the consequences of these declines for ecosystem function. Here, we review progress in our understanding of how megafauna affect ecosystem physical and trophic structure, species composition, biogeochemistry, and climate, drawing on special features of PNAS and Ecography that have been published as a result of an international workshop on this topic held in Oxford in 2014. Insights emerging from this work have consequences for our understanding of changes in biosphere function since the Late Pleistocene and of the functioning of contemporary ecosystems, as well as offering a rationale and framework for scientifically informed restoration of megafaunal function where possible and appropriate.
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