2509001561
  • Open Access
  • Article

The four stages of the Sixth Mass Extinction

  • Thomas J. Algeo 1,2,3,4*,   
  • Shucheng Xie 2,5

Received: 18 Mar 2025 | Revised: 01 Apr 2025 | Accepted: 04 Apr 2025 | Published: 07 Apr 2025

Abstract

The Earth stands on the brink of another global biocrisis, commonly dubbed the Sixth Mass Extinction (SME) in reference to the Big Five Phanerozoic mass extinctions that have episodically transformed the biosphere through time. Relative to these earlier extinctions, the present-day biocrisis is unique in being a carbon-release event with a bioevolutionary trigger, i.e., the development of technology to an extent that gives humans near-ubiquitous influence over the Earth’s climatic, environmental, and biospheric systems.  Although the SME started slowly and in a punctuated manner, its pace has accelerated sharply in the last 100-200 years and is likely to continue to do so in the future, implying that the peak of the biocrisis may be no more than a few hundred years away. Although not sharply delineated in time, the four stages of the SME are: Stage 1—hunting and overexploitation (~50-0.25 ka); Stage 2—habitat loss (~0.25 ka to present); Stage 3—climate change and alien species invasions (~0.1 ka to the near-future); and Stage 4—ecosystem collapse (middle future). Each of the first three stages were associated with a technological development that initiated and contributed to coeval biodiversity declines, e.g., advances in early human hunting technology (Stage 1), the spread of agriculture and animal husbandry (Stage 2), and industrialization and combustion of fossil fuels (Stage 3). The fourth stage, ecosystem collapse, is unlikely to require another human developmental trigger—rather, it will come about spontaneously in response to widespread, intense degradation of habitats and biotic communities by human pressures.

References 

  • 1.
    Brooks, T.M., Mittermeier, R.A., Mittermeier, C.G., Da Fonseca, G.A., Rylands, A.B., Konstant, W.R., Flick, P., Pilgrim, J., Oldfield, S., Magin, G., Hilton-Taylor, C., 2002. Habitat loss and extinction in the hotspots of biodiversity. Conserv. Biol. 16(4), 909–923.
  • 2.
    Broughton, J.M., Weitzel, E.M., 2018. Population reconstructions for humans and megafauna suggest mixed causes for North American Pleistocene extinctions. Nat. Commun. 9(1), 5441.
  • 3.
    Burrows, M.T., Schoeman, D.S., Buckley, L.B., Moore, P., Poloczanska, E.S., Brander, K.M., Brown, C., Bruno, J.F., Duarte, C.M., Halpern, B.S., Holding, J., 2011. The pace of shifting climate in marine and terrestrial ecosystems. Science 334(6056), 652–655.
  • 4.
    Cahill, A.E., Aiello-Lammens, M.E., Fisher-Reid, M.C., Hua, X., Karanewsky, C.J., Yeong Ryu, H., Sbeglia, G.C., Spagnolo, F., Waldron, J.B., Warsi, O., Wiens, J.J., 2013. How does climate change cause extinction? Proc. Roy. Soc. B: Biol. Sci. 280, 20121890.
  • 5.
    Calizza, E., Costantini, M.L., Careddu, G., Rossi, L., 2017. Effect of habitat degradation on competition, carrying capacity, and species assemblage stability. Ecol. Evol. 7(15), 5784–5796.
  • 6.
    Canadell, J.G., Jackson, R.B., 2021. Ecosystem collapse and climate change: an introduction. Ecosystem Collapse and Climate Change, Ecological Studies, vol. 241, Springer, p. 1–9.
  • 7.
    Ceballos, G., Ehrlich, P.R., Barnosky, A.D., Garca, A., Pringle, R.M., Palmer, T.M., 2015. Accelerated modern human–induced species losses: entering the sixth mass extinction. Sci. Adv. 1(5), e1400253.
  • 8.
    Ceballos, G., Ehrlich, P.R., Raven, P.H., 2020. Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction. Proc. Natl. Acad. Sci. (U.S.A.) 117, 13596–13602.
  • 9.
    Cowan, Z.L., Pratchett, M., Messmer, V., Ling, S., 2017. Known predators of crown-of-thorns starfish (Acanthaster spp.) and their role in mitigating, if not preventing, population outbreaks. Diversity 9(1), 7.
  • 10.
    Crimmins, S.M., Dobrowski, S.Z., Greenberg, J.A., Abatzoglou, J.T., Mynsberge, A.R., 2011. Changes in climatic water balance drive down- hill shifts in plant species’ optimum elevations. Science 331, 324–327. Crowley, B.E., 2010. A refined chronology of prehistoric Madagascar and the demise of the megafauna. Quat. Sci. Rev. 29(19–20), 2591–2603.
  • 11.
    Dal Corso, J., Song, H., Callegaro, S., Chu, D., Sun, Y., Hilton, J., Grasby, S.E., Joachimski, M.M., Wignall, P.B., 2022. Environmental crises at the Permian-Triassic mass extinction. Nat. Rev. Earth Environ. 3(3), 197–214.
  • 12.
    Deutsch, C.A., Tewksbury, J.J., Huey, R.B., Sheldon, K.S., Ghalambor, C.K., Haak, D.C., Martin, P.R., 2008. Impacts of climate warming on terrestrial ectotherms across latitude. Proc. Natl. Acad. Sci. (U.S.A.) 105(18), 6668–6672.
  • 13.
    De Vos, J.M., Joppa, L.N., Gittleman, J.L., Stephens, P.R., Pimm, S.L., 2015. Estimating the normal background rate of species extinction. Conserv. Biol. 29(2), 452–462.
  • 14.
    Diamond, J., 2011. Collapse: How Societies Choose to Fail or Succeed. 2nd edn., Penguin.
  • 15.
    DiNapoli, R.J., Lipo, C.P., Hunt, T.L., 2020. Revisiting warfare, monument destruction, and the ‘Huri Moai’ phase in Rapa Nui (Easter Island) culture history. J. Pac. Archaeol. 12(1), p. 24.
  • 16.
    Dirzo, R., Young, H.S., Galetti, M., Ceballos, G., Isaac, N.J., Collen, B., 2014. Defaunation in the Anthropocene. Science 345, 401–406.
  • 17.
    Downey, S.S., Haas, W.R., Shennan, S.J., 2016. European Neolithic societies showed early warning signals of population collapse. Proc. Natl. Acad. Sci. (U.S.A.) 113, 9751–9756.
  • 18.
    Driscoll, D.A., Armenteras, D., Bennett, A.F., Brotons, L., Clarke, M.F., Doherty, T.S., Haslem, A., Kelly, L.T., Sato, C.F., Sitters, H., Aquilu, N., 2021. How fire interacts with habitat loss and fragmentation. Biol. Rev. 96(3), 976–998.
  • 19.
    Driscoll, D.A., Catford, J.A., Barney, J.N., Hulme, P.E., Inderjit, Martin, T.G., Pauchard, A., Pyek, P., Richardson, D.M., Riley, S., Visser, V., 2014. New pasture plants intensify invasive species risk. Proc. Natl. Ac˜ ad. Sci. (U.S.A.) 111(46), 16622–16627.
  • 20.
    Duenas, M.A., Ruffhead, H.J., Wakefield, N.H., Roberts, P.D., Hemming, D.J., Diaz-Soltero, H., 2018. The role played by invasive species in interactions with endangered and threatened species in the United States: a systematic review. Biodivers. Conserv. 27, 3171–3183.
  • 21.
    Duncan, R.P., Boyer, A.G., Blackburn, T.M., 2013. Magnitude and variation of prehistoric bird extinctions in the Pacific. Proc. Natl. Acad. Sci. (U.S.A.) 110(16), 6436–6441.
  • 22.
    Durance, I., Ormerod, S.J., 2010. Evidence for the role of climate in the local extinction of a cool-water triclad. J. N. Am. Benthol. Soc. 29, 1367–1378.
  • 23.
    Epps, C.W., McCullough, D.R., Wehausen, J.D., Bleich, V.C., Rechel, J.L., 2004. Effects of climate change on population persistence of desertdwelling mountain sheep in California. Conserv. Biol. 18(1), 102–113.
  • 24.
    Ermakhanov, Z.K., Plotnikov, I.S., Aladin, N.V., Micklin, P., 2012. Changes in the Aral Sea ichthyofauna and fishery during the period of ecological crisis. Lakes Reserv.: Res. Manag. 17, 3–9.
  • 25.
    Feng, X., Merow, C., Liu, Z., Park, D.S., Roehrdanz, P.R., Maitner, B., Newman, E.A., Boyle, B.L., Lien, A., Burger, J.R., Pires, M.M., 2021. How deregulation, drought and increasing fire impact Amazonian biodiversity. Nature 597(7877), 516–521.
  • 26.
    Fischer, J., Lindenmayer, D.B., 2007. Landscape modification and habitat fragmentation: a synthesis. Glob. Ecol. Biogeogr. 16(3), 265–280.
  • 27.
    Forseth, I.N., Innis, A.F., 2004. Kudzu (Pueraria montana): history, physiology, and ecology combine to make a major ecosystem threat. Crit. Rev. Plant Sci. 23(5), 401–413.
  • 28.
    Fricke, E.C., Hsieh, C., Middleton, O., Gorczynski, D., Cappello, C.D., Sanisidro, O., Rowan, J., Svenning, J.C., Beaudrot, L., 2022. Collapse of terrestrial mammal food webs since the Late Pleistocene. Science 377(6609), 1008–1011.
  • 29.
    Gaschk, J.L., Clemente, C.J., 2022. Classifying relationships that define interactions between native and invasive species in Australian ecosystems. Aust. J. Zool. 70(1), 22–35.
  • 30.
    Gerlach, J., Barker, G.M., Bick, C.S., Bouchet, P., Brodie, G., Christensen, C.C., Collins, T., Coote, T., Cowie, R.H., Fiedler, G.C., 2021. Negative impacts of invasive predators used as biological control agents against the pest snail Lissachatina Fulica: the snail Euglandina ‘rosea’ and the flatworm Platydemus manokwari. Biol. Invas. 23, 997–1031.
  • 31.
    Gill, J.L., Williams, J.W., Jackson, S.T., Lininger, K.B., Robinson, G.S., 2009. Pleistocene megafaunal collapse, novel plant communities, and enhanced fire regimes in North America. Science 326, 1100–1103.
  • 32.
    Harley, C.D.G., 2011. Climate change, keystone predation, and biodiversity loss. Science 334, 1124–1127.
  • 33.
    Harvell, C.D., Mitchell, C.E., Ward, J.R., Altizer, S., Dobson, A.P., Ostfeld, R.S., Samuel, M.D., 2002. Climate warming and disease risks for terrestrial and marine biota. Science 296, 2158–2162.
  • 34.
    Hedges, S.B., Cohen, W.B., Timyan, J., Yang, Z., 2018. Haiti’s biodiversity threatened by nearly complete loss of primary forest. Proc. Natl. Acad. Sci. (U.S.A.) 115(46), 11850–11855.
  • 35.
    Hof, C., Arajo, M.B., Jetz, W., Rahbek, C., 2011. Additive threats from pathogens, climate and land-use change for global amphibian diversity. Nature 480(7378), 516–519.
  • 36.
    Hoffecker, J.F., 2017. Modern Humans: Their African Origin and Global Dispersal. Columbia University Press, New York, p. 533.
  • 37.
    Hooper, D.U., Adair, E.C., Cardinale, B.J., Byrnes, J.E., Hungate, B.A., Matulich, K.L., Gonzalez, A., Duffy, J.E., Gamfeldt, L., O’Connor, M.I., 2012. A global synthesis reveals biodiversity loss as a major driver of ecosystem change. Nature 486(7401), 105–108.
  • 38.
    Hutchings, J.A., Myers, R.A., 1994. What can be learned from the collapse of a renewable resource? Atlantic cod, Gadus morhua, of Newfoundland and Labrador. Canad. J. Fisher. Aquat. Sci. 51(9), 2126–2146.
  • 39.
    Jeschke, J.M., Strayer, D.L., 2005. Invasion success of vertebrates in Europe and North America. Proc. Natl. Acad. Sci. (U.S.A.) 102(20), 7198–7202.
  • 40.
    Jetz, W., Wilcove, D.S., Dobson, A.P., 2007. Projected impacts of climate and land-use change on the global diversity of birds. PLoS Biology 5(6), e157.
  • 41.
    Johnson, C.N., 2009. Ecological consequences of Late Quaternary extinctions of megafauna. Proc. R. Soc. B: Biol. Sci. 276(1667), 2509–2519.
  • 42.
    Jordn, F., 2009. Keystone species and food webs. Phil. Trans. Roy. Soc. B: Biol. Sci. 364(1524), 1733–1741.
  • 43.
    Kearney, M., Shine, R., Porter, W.P., 2009. The potential for behavioral thermoregulation to buffer “cold-blooded” animals against climate warming. Proc. Natl. Acad. Sci. (U.S.A.) 106(10), 3835 3840.
  • 44.
    Keith, D.A., Rodr´guez, J.P., Rodr´guez-Clark, K.M., and 30 coauthors, 2013. Scientific foundations for an IUCN Red List of ecosystems. PLoS One 8(5), e62111.
  • 45.
    Kilpatrick, A.M., Briggs, C.J., Daszak, P., 2010. The ecology and impact of chytridiomycosis: an emerging disease of amphibians. Trends Ecol. Evol. 25(2), 109 118.
  • 46.
    Krysko, K.L., Burgess, J.P., Rochford, M.R., Gillette, C.R., Cueva, D., Enge, K.M., Somma, L.A., Stabile, J.L., Smith, D.C., Wasilewski, J.A., 2011. Verified non-indigenous amphibians and reptiles in Florida from 1863 through 2010: outlining the invasion process and identifying invasion pathways and stages. Zootaxa 3028, 1 64.
  • 47.
    Laidre, K.L., Born, E.W., Atkinson, S.N., Wiig, Ø., Andersen, L.W., Lunn, N.J., Dyck, M., Regehr, E.V., McGovern, R., Heagerty, P., 2018. Range contraction and increasing isolation of a polar bear subpopulation in an era of sea-ice loss. Ecol. Evol. 8(4), 2062 2075.
  • 48.
    Laurance, W.F., Camargo, J.L., Fearnside, P.M., Lovejoy, T.E., Williamson, G.B., Mesquita, R.C., Meyer, C.F., Bobrowiec, P.E., Laurance, S.G., 2018. An Amazonian rainforest and its fragments as a laboratory of global change. Biol. Rev. 93(1), 223 247.
  • 49.
    Lawlor, J.A., Comte, L., Grenouillet, G., Lenoir, J., Baecher, J.A., Bandara, R.M.W.J., Bertrand, R., Chen, I.C., Diamond, S.E., Lancaster, L.T., Moore, N., 2024. Mechanisms, detection and impacts of species redistributions under climate change. Nat. Rev. Earth Environ. 5(5), 351 368.
  • 50.
    Lennon, D., 2022. Human population collapse may be closer than we think. E: The Environmental Magazine (https://emagazine.com). Retrieved 16 March 2025.
  • 51.
    Lenoir, J., Bertrand, R., Comte, L., Bourgeaud, L., Hattab, T., Murienne, J., Grenouillet, G., 2020. Species better track climate warming in the oceans than on land. Nature Ecol. Evol. 4(8), 1044 1059.
  • 52.
    Lipo, C.P., Hunt, T.L., 2006. Chronology and Easter Island prehistory, in: Stefan, V.H., Gill, G.W. (Eds.), Skeletal Biology of the Ancient Rapanui (Easter Islanders). Cambridge University Press, Cambridge, UK, p. 39 65.
  • 53.
    Lockwood, J.L., Welbourne, D.J., Romagosa, C.M., Cassey, P., Mandrak, N.E., Strecker, A., Leung, B., Stringham, O.C., Udell, B., EpiscopioSturgeon, D.J., Tlusty, M.F., 2019. When pets become pests: the role of the exotic pet trade in producing invasive vertebrate animals. Front. Ecol. Environ. 17(6), 323 330.
  • 54.
    Luo, G., Liu, D., Yang, H., 2024. Microbes in mass extinction: an accomplice or a savior? Nat. Sci. Rev. 11(1), nwad291.
  • 55.
    MacDougall, A.S., McCann, K.S., Gellner, G., Turkington, R., 2013. Diversity loss with persistent human disturbance increases vulnerability to ecosystem collapse. Nature 494, 86 89.
  • 56.
    Martin, P.S., 1989. Prehistoric overkill: a global model, in: Martin, P.S., Klein, R.G. (Eds.), Quaternary Extinctions: A Prehistoric Revolution. Univ. Arizona Press, p. 354 404.
  • 57.
    Mazzamuto, M.V., Wauters, L.A., Koprowski, J.L., 2021. Exotic pet trade as a cause of biological invasions: the case of tree squirrels of the genus Callosciurus. Biology 10(10), 1046.
  • 58.
    McLaughlin, J.F., Hellmann, J.J., Boggs, C.L., Ehrlich, P.R., 2002. Climate change hastens population extinctions. Proc. Natl. Acad. Sci. (U.S.A.) 99(9), 6070 6074.
  • 59.
    Memmott, J., Craze, P.G., Waser, N.M., Price, M.V., 2007. Global warming and the disruption of plant pollinator interactions. Ecol. Lett. 10(8), 710 717.
  • 60.
    Micklin, P., 2007. The Aral Sea disaster. Annu. Rev. Earth Planet. Sci. 35(1), 47 72.
  • 61.
    Micklin, P., Aladin, N.V., 2008. Reclaiming the Aral Sea. Sci. Am. 298(4), 64 71.
  • 62.
    Miehls, A.L.J., Mason, D.M., Frank, K.A., Krause, A.E., Peacor, S.D., Taylor, W.W., 2009. Invasive species impacts on ecosystem structure and function: a comparison of Oneida Lake, New York, USA, before and after zebra mussel invasion. Ecol. Model. 220(22), 3194 3209.
  • 63.
    Mieth, A., Bork, H.R., 2005. History, origin and extent of soil erosion on Easter Island (Rapa Nui). Catena 63, 224 260.
  • 64.
    Miller, G.H., Fogel, M.L., Magee, J.W., Gagan, M.K., Clarke, S.J., Johnson, B.J., 2005. Ecosystem collapse in Pleistocene Australia and a human role in megafaunal extinction. Science 309, 287 290.
  • 65.
    Mitchell, N.J., Janzen, F.J., 2010. Temperature-dependent sex determination and contemporary climate change. SA. Dev. 4(1 2), 129 140.
  • 66.
    Moodley, Y., Russo, I.R.M., Dalton, D.L., Kotz, A., Muya, S., Haubensak, P., Blint, B., Munimanda, G.K., Deimel, C., Setzer, A., Dicks, K., 2017. Extinctions, genetic erosion and conservation options for the black rhinoceros ( Diceros bicornis). Sci. Rept. 7(1), 41417.
  • 67.
    Mora, C., Tittensor, D.P., Adl, S., Simpson, A.G., Worm, B., 2011. How many species are there on Earth and in the ocean? PLoS Biology 9(8), e1001127.
  • 68.
    Newton, A.C., Coward, F., Elliott, S., Jenkins, E., Linden, M.V., Riris, P., Silva, F., 2024. Understanding long-term human ecodynamics through the lens of ecosystem collapse. Holocene 34(10), 1439 1453.
  • 69.
    Ocampo-Penuela, N., Garcia-Ulloa, J., Kornecki, I., Philipson, C.D., Ghazoul, J., 2020. Impacts of four decades of forest loss on vertebrate functional habitat on Borneo. Front. For. Glob. Change 3, 53.
  • 70.
    O'Leary, D., 2021. Rapanui: The People of Easter Island. Floricanto Press, Puerto Rico, p. 123.
  • 71.
    Parmesan, C., Yohe, G., 2003. A globally coherent fingerprint of climate change impacts across natural systems. Nature 421, 37 42.
  • 72.
    Pauchard, A., Milbau, A., Albihn, A., Alexander, J., Burgess, T., Daehler, C., Englund, G., Essl, F., Evengrd, B., Greenwood, G.B., Haider, S., 2016. Non-native and native organisms moving into high elevation and high latitude ecosystems in an era of climate change: new challenges for ecology and conservation. Biol. Invas. 18, 345 353.
  • 73.
    Pedersen, S., Christie, A., Kennedy, P.J., Osborne, J.L., O'Shea-Wheller, T.A., Tyler, C.R., 2025. Broad ecological threats of an invasive hornet revealed through a deep sequencing approach. Sci. Total Environ. 970, 178978.
  • 74.
    Phelps, Q.E., Tripp, S.J., Bales, K.R., James, D., Hrabik, R.A., Herzog, D.P., 2017. Incorporating basic and applied approaches to evaluate the effects of invasive Asian Carp on native fishes: a necessary first step for integrated pest management. PloS One 12(9), e0184081.
  • 75.
    Prtner, H.O., Knust, R., 2007. Climate change affects marine fishes through the oxygen limitation of thermal tolerance. Science 315, 95 97.
  • 76.
    Pounds, J.A., Bustamante, M.R., Coloma, L.A., Consuegra, J.A., Fogden, M.P., Foster, P.N., La Marca, E., Masters, K.L., Merino-Viteri, A., Puschendorf, R., Ron, S.R., 2006. Widespread amphibian extinctions from epidemic disease driven by global warming. Nature 439(7073), 161 167.
  • 77.
    Raza, M.M., Bebber, D.P., 2022. Climate change and plant pathogens. Curr. Opin. Microbiol. 70, 102233.
  • 78.
    Rhyne, A.L., Tlusty, M.F., Schofield, P.J., 2012. Revealing the appetite of the marine aquarium fish trade: the volume and biodiversity of fish imported into the United States. PLoS One 7, e35808.
  • 79.
    Ricciardi, A., 2001. Facilitative interactions among aquatic invaders: is an invasional meltdown occurring in the Great Lakes? Can. J. Fish. Aquat. Sci. 58, 2513 2525.
  • 80.
    Roberts, D.L., Solow, A.R., 2003. When did the dodo become extinct? Nature 426, 245 245.
  • 81.
    Rodda, G.H., Savidge, J.A., 2007. Biology and impacts of Pacific island invasive species. 2. Boiga irregularis, the brown tree snake (Reptilia: colubridae). Pacific Sci. 61(3), 307 324.
  • 82.
    Roopnarine, P.D., Banker, R.M., Sampson, S.D., 2022. Impact of the extinct megaherbivore Steller's sea cow (Hydrodamalis gigas) on kelp forest resilience. Front. Ecol. Evol. 10, 983558.
  • 83.
    Rosa, C.A., de Almeida Curi, N.H., Puertas, F., Passamani, M., 2017. Alien terrestrial mammals in Brazil: current status and management. Biol. Invas. 19, 2101 2123.
  • 84.
    Runge, M.C., Sanders-Reed, C.A., Langtimm, C.A., Hostetler, J.A., Martin, J., Deutsch, C.J., Ward-Geiger, L.I., Mahon, G.L., 2017. Status and threats analysis for the Florida manatee (Trichechus manatus latirostris), 2016 (No. 2017-5030). U.S. Geological Survey.
  • 85.
    Schweiger, O., Heikkinen, R.K., Harpke, A., Hickler, T., Klotz, S., Kudrna, O., Khn, I., Pyry, J., Settele, J., 2012. Increasing range mismatching of interacting species under global change is related to their ecological characteristics. Glob. Ecol. Biogeogr. 21(1), 88 99.
  • 86.
    Seebens, H., Bacher, S., Blackburn, T.M., Capinha, C., Dawson, W., Dullinger, S., Genovesi, P., Hulme, P.E., Kleunen, M., Khn, I., Jeschke, J.M., 2021. Projecting the continental accumulation of alien species through to 2050. Glob. Chang. Biol. 27(5), 970 982.
  • 87.
    Sepkoski, Jr, J.J., 1996. Patterns of phanerozoic extinction: a perspective from global data bases, in: Walliser, O.H. (Ed.), Global Events and Event Stratigraphy. Springer, Berlin, p. 35 51.
  • 88.
    Shiels, A.B., Pitt, W.C., Sugihara, R.T., Witmer, G.W., 2014. Biology and impacts of Pacific island invasive species. 11. Rattus rattus, the black rat (rodentia: Muridae). Pacific Sci. 68(2), 145 184.
  • 89.
    Smith, K.F., Goldberg, M., Rosenthal, S., Carlson, L., Chen, J., Chen, C., Ramachandran, S., 2014. Global rise in human infectious disease outbreaks. J. R. Soc. Interface 11(101), 20140950.
  • 90.
    Spatz, D.R., Zilliacus, K.M., Holmes, N.D., Butchart, S.H.M., Genovesi, P., Ceballos, G., Tershy, B.R., Croll, D.A., 2017. Globally threatened vertebrates on islands with invasive species. Sci. Adv. 3, e1603080.
  • 91.
    Stevenson, C.M., Puleston, C.O., Vitousek, P.M., Chadwick, O.A., Haoae, S., Ladefoged, N., 2015. Variation in Rapa Nui (Easter Island) land use indicates production and population peaks prior to European contact, proc. Natl. Acad. Sci. (U.S.A.) 112, 1025 1030.
  • 92.
    Stuart, A.J., 1999. Late Pleistocene megafaunal extinctions: a European perspective, in: MacPhee, R.D. (Ed.), Extinctions in Near Time. Springer, Boston, MA, p. 257 269.
  • 93.
    Stuart, A.J., Lister, A.M., 2012. Extinction chronology of the woolly rhinoceros Coelodonta antiquitatis in the context of late Quaternary megafaunal extinctions in northern Eurasia. Quat. Sci. Rev. 51, 1 17.
  • 94.
    Surovell, T.A., Pelton, S.R., Anderson-Sprecher, R., Myers, A.D., 2016. Test of Martin's overkill hypothesis using radiocarbon dates on extinct megafauna. Proc. Natl. Acad. Sci. (U.S.A.) 113(4), 886 891.
  • 95.
    Surovell, T.A., Waguespack, N., Brantingham, P.J., 2005. Global archaeological evidence for proboscidean overkill. Proc. Natl. Acad. Sci. (U.S.A.) 102(17), 6231 6236.
  • 96.
    Thomas, C.D., Cameron, A., Green, R.E., Bakkenes, M., Beaumont, L.J., Collingham, Y.C., Erasmus, B.F., De Siqueira, M.F., Grainger, A., Hannah, L., Hughes, L., 2004. Extinction risk from climate change. Nature 427, 145 148.
  • 97.
    Todd, N.E., 2006. Trends in proboscidean diversity in the African Cenozoic. J. Mammal. Evol. 13(1), 1 10.
  • 98.
    Turbelin, A.J., Cuthbert, R.N., Essl, F., Haubrock, P.J., Ricciardi, A., Courchamp, F., 2023. Biological invasions are as costly as natural hazards. Perspect. Ecol. Conserv. 21, 143 150. [online].
  • 99.
    Turvey, S., 2009. Witness to Extinction: How We Failed to Save the Yangtze River Dolphin. Oxford University Press, USA.
  • 100.
    Tylianakis, J.M., Didham, R.K., Bascompte, J., Wardle, D.A., 2008. Global change and species interactions in terrestrial ecosystems. Ecol. Lett. 11(12), 1351 1363.
  • 101.
    U.N., DESA, Population Division, 2022. World population prospects 2022, (https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/wpp2022_summary_of_results.pdf).
  • 102.
    Urban, M.C., 2015. Accelerating extinction risk from climate change. Science 348, 571 573.
  • 103.
    Valry, L., Fritz, H., Lefeuvre, J.C., Simberloff, D., 2008. In search of a real definition of the biological invasion phenomenon itself. Biological Invasions 10, 1345 1351.
  • 104.
    Vil, M., Espinar, J.L., Hejda, M., Hulme, P.E., Jaro´k, V., Maron, J.L., Pergl, J., Schaffner, U., Sun, Y., Pyek, P., 2011. Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems. Ecol. Lett. 14(7), 702 708.
  • 105.
    Vincent, W.F., Mueller, D., 2020. Witnessing ice habitat collapse in the Arctic. Science 370(6520), 1031 1032.
  • 106.
    Visser, M.E., van Noordwijk, A.J., Tinbergen, J.M., Lessells, C.M., 1998. Warmer springs lead to mistimed reproduction in great tits (Parus major). Proc. R. Soc. Lond. B 265, 1867 1870.
  • 107.
    Walika, M., De Almeida, M.M., Delgado, R.C., Gonzlez, P.A., 2023. Outbreaks following natural disasters: a review of the literature. Disaster Med. Public Health Prep. 17, e444.
  • 108.
    Werdelin, L., Lewis, M.E., 2013. Temporal change in functional richness and evenness in the eastern African Plio-Pleistocene carnivoran guild. PLoS One 8(3), e57944.
  • 109.
    Wethey, D.S., 2002. Biogeography, competition, and microclimate: the barnacle Chthamalus fragilis in New England. Integr. Comp. Biol. 42(4), 872 880.
  • 110.
    Woinarski, J.C., Burbidge, A.A., Harrison, P.L., 2015. Ongoing unraveling of a continental fauna: decline and extinction of Australian mammals since European settlement. Proc. Natl. Acad. Sci. (U.S.A.) 112(15), 4531 4540.
  • 111.
    Xie, S., Pancost, R.D., Yin, H., Wang, H., Evershed, R.P., 2005. Two episodes of microbial change coupled with permo/Triassic faunal mass extinction. Nature 434(7032), 494 497.
  • 112.
    Xie, S., Zhu, X., Algeo, T., Qiu, X., 2023. Geovirology: viruses and their roles in geological history. Sci. Bull. 68(4), 379 382.
  • 113.
    Ytrehus, B., Bretten, T., Bergsjø, B., Isaksen, K., 2008. Fatal pneumonia epizootic in musk ox ( Ovibos moschatus) in a period of extraordinary weather conditions. EcoHealth 5, 213 223.
Share this article:
How to Cite
Algeo, T. J., & Xie, S. (2025). The four stages of the Sixth Mass Extinction. Habitable Planet, 1(1&2), 20–33. https://doi.org/10.63335/j.hp.2025.0003
RIS
BibTex
Copyright & License
article copyright Image
Copyright (c) 2025 by the authors.