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Disagreement or denialism? “Invasive species denialism” and ethical disagreement in science

  • David M. FrankEmail author
S.I.: Disagreement in Science


Recently, invasion biologists have argued that some of the skepticism expressed in the scientific and lay literatures about the risks of invasive species and other aspects of the consensus within invasion biology is a kind of science denialism. This paper presents an argument that, while some claims made by skeptics of invasion biology share important features with paradigm cases of science denialism, others express legitimate ethical concerns that, even if one disagrees, should not be dismissed as denialist. Further, this case illustrates a more general point about ethical disagreement within sciences like invasion biology that constitutively pursue non-epistemic goals and values. While philosophers of science have argued that epistemic disagreement within science can be productive as heterogeneous epistemic communities “hedge their bets,” the case of invasion biology shows how non-epistemic or ethical disagreement within sciences, while carrying significant risks, can also be epistemically and non-epistemically valuable.


Invasion biology Invasive species Science denialism Value-laden science Ethical disagreement 



Special thanks to ecologists Dan Simberloff and Christy Leppanen for the opportunity to participate in research on invasive species, for many lively conversations, and comments on the manuscript. Thanks also to Dale Jamieson, Jennifer Jacquet, members of the Department of Philosophy at the University of Tennessee, and two anonymous referees for constructive comments and criticisms.


  1. Alberti, M., Marzluff, J., Shulenberger, E., Bradley, G., Ryan, C., & Zumbrunnen, C. (2003). Integrating humans into ecology: Opportunities and challenges for studying urban ecosystems. BioScience, 53, 1169–1179.Google Scholar
  2. Baker, H. G., & Stebbins, G. L. (Eds.). (1965). The genetics of colonizing species. In Proceedings of the international union of biological sciences. New York: Academic Press.Google Scholar
  3. Bellard, C., Cassey, P., & Blackburn, T. M. (2016). Alien species as a driver of recent extinctions. Biological Letters, 12, 20150623.Google Scholar
  4. Biddle, J. B., & Leuschner, A. (2015). Climate skepticism and the manufacture of doubt: Can dissent in science be epistemically detrimental? European Journal for Philosophy of Science, 5(3), 261–278.Google Scholar
  5. Blackburn, T. M., Essl, F., Evans, T., Hulme, P. E., Jeschke, J. M., et al. (2014). A unified classification of alien species based on the magnitude of their environmental impacts. PLoS Biology, 12(5), e1001850.Google Scholar
  6. Boorse, C. (1977). Health as a theoretical concept. Philosophy of Science, 44(4), 542–573.Google Scholar
  7. Brown, J., & Sax, D. (2004). An essay on some topics concerning invasive species. Austral Ecology, 29, 530–536.Google Scholar
  8. Buckley, Y. M., & Catford, J. (2016). Does the biogeographic origin of species matter? Ecological effects of native and non-native species and the use of origin to guide management. Journal of Ecology, 104, 4–17.Google Scholar
  9. Chew, M. K. (2011). Anekeitaxonomy: Botany, place, and belonging. In D. Rotherham & R. A. Lambert (Eds.), Invasive and introduced plants and animals: Human perceptions, attitudes, and approaches to management. Washington, DC: Earthscan.Google Scholar
  10. Chew, M. K. (2015). Ecologists, environmentalists, experts, and the invasion of the ‘second greatest threat’. International Review of Environmental History, 1, 17–40.Google Scholar
  11. Chew, M. K., & Hamilton, A. (2011). The rise and fall of biotic nativeness: A historical perspective. In D. M. Richardson (Ed.), Fifty years of invasion ecology: The legacy of Charles Elton. New York, NJ, Hoboken: Wiley.Google Scholar
  12. Clark, H. (2006). Invasion biology: Critique of a pseudoscience by David Theodoropoulos. Western North American Naturalist, 66(4), 537–539.Google Scholar
  13. Clavero, M., & Garcia-Berthou, E. (2005). Invasive species are a leading cause of animal extinctions. Trends in Ecology & Evolution, 20(3), 110.Google Scholar
  14. Coates, P. (2006). American perceptions of immigrant and invasive species. Berkeley, CA: University of California Press.Google Scholar
  15. Colautti, R. I., & Richardson, D. M. (2009). Subjectivity and flexibility in invasion terminology: Too much of a good thing? Biological Invasions, 11(6), 1225–1229.Google Scholar
  16. Cronon, W. (1995). The trouble with wilderness; or, getting back to the wrong nature. In W. Cronon (Ed.), Uncommon ground: Rethinking the human place in nature (pp. 69–90). New York: Norton.Google Scholar
  17. Crowley, S. L., Hinchliffe, S., Redpath, S. M., & McDonald, R. A. (2017). Disagreement about invasive species does not equate to denialism: A response to Russell and Blackburn. Trends in Ecology & Evolution, 32(4), 228–229.Google Scholar
  18. Davis, M. A. (2006). Invasion biology 1958–2005: The pursuit of science and conservation. In M. W. Cadotte, S. M. McMahon, & T. Fukami (Eds.), Conceptual ecology and invasion biology (pp. 35–64). Dordrecht: Springer.Google Scholar
  19. Davis, M. A. (2009). Invasion biology. New York: Oxford University Press.Google Scholar
  20. Davis, M. A., & Chew, M. K. (2017). ‘The denialists are coming!’ Well, not exactly: A response to Russell and Blackburn. Trends in Ecology & Evolution, 32(4), 229–230.Google Scholar
  21. Davis, M. A., et al. (2011). Don’t judge species on their origins. Nature, 474, 153–154.Google Scholar
  22. De Cruz, H., & De Smedt, J. (2013). The value of epistemic disagreement in scientific practice. The case of Homo floresiensis. Studies in History and Philosophy of Science, 44, 169–177.Google Scholar
  23. De Melo-Martín, I., & Intemann, K. (2018). The fight against doubt: How to bridge the gap between scientists and the public. New York: Oxford University Press.Google Scholar
  24. Dellsén, F. (2018). When expert disagreement supports the consensus. Australasian Journal of Philosophy, 96(1), 142–156.Google Scholar
  25. Diethelm, P., & McKee, M. (2009). Denialism: What is it and how should scientists respond? European Journal of Public Health, 19(1), 2–4.Google Scholar
  26. Douglas, H. (2000). Inductive risk and values in science. Philosophy of Science, 67(4), 559–579.Google Scholar
  27. Douglas, H. (2006). Bullshit at the interface of science and policy: Global warming, toxic substances, and other pesky problems. In H. Reisch (Ed.), Bullshit and philosophy (pp. 213–226). Chicago: Open Court.Google Scholar
  28. Douglas, H. (2016). Values in science. In P. Humphreys (Ed.), The Oxford handbook of philosophy of science. New York: Oxford University Press.Google Scholar
  29. Dowie, M. (2003). Conservation refugees. Cambridge, MA: MIT Press.Google Scholar
  30. Elliott, K. C. (2009). The ethical significance of language in the environmental sciences: Case studies from pollution research. Ethics, Place, and Environment, 12(2), 157–173.Google Scholar
  31. Elliott, K. C. (2011). Is a little pollution good for you? Incorporating societal values in environmental research. New York: Oxford University Press.Google Scholar
  32. Elliott, K. C., & McKaughan, D. J. (2014). Nonepistemic values and the multiple goals of science. Philosophy of Science, 81, 1–21.Google Scholar
  33. Elliott, K. C., & Richards, T. (Eds.). (2017). Exploring inductive risk: Case studies of values in science. New York: Oxford University Press.Google Scholar
  34. Elton, C. C. (1958). The ecology of invasions by animals and plants. London: Methuen.Google Scholar
  35. Frances, B., & Matheson, J. (2018). Disagreement. In E. N. Zalta (Ed.), The Stanford encyclopedia of philosophy (Spring 2018 Edition).
  36. Frank, D. M. (2017). Ethics of the scientist qua policy advisor: Inductive risk, uncertainty, and catastrophe in climate economics. Synthese, S.I.: Evidence Amalgamation in the Sciences. Scholar
  37. Gould, S. J. (1998). An evolutionary perspective on strengths, fallacies, and confusions in the concept of native plants. Arnoldia, 58(1), 3–10.Google Scholar
  38. Gröning, G., & Wolschke-Bulmahn, J. (1992). Some notes on the mania for native plants in Germany. Landscape Journal, 11, 116–126.Google Scholar
  39. Guha, R. (1989). Radical American environmentalism and wilderness preservation: A third world critique. Environmental Ethics, 11(1), 71–83.Google Scholar
  40. Guiaşu, R. C., & Tindale, C. W. (2018). Logical fallacies and invasion biology. Biology and Philosophy, 33, 34.Google Scholar
  41. Gurevitch, J., & Padilla, D. K. (2004). Are invasive species a major cause of extinction? Trends in Ecology & Evolution, 19, 470–474.Google Scholar
  42. Heneghan, L. (2015). Is there a need for ‘The New Wild’? The new ecological quarrels. Los Angeles Review of Books. Accessed October 1, 2018.
  43. Hobbs, R. J., Higgs, E., & Harris, J. A. (2009). Novel ecosystems: Implications for conservation and restoration. Trends in Ecology & Evolution, 24(11), 599–605.Google Scholar
  44. Hubbell, S. P. (2001). The unified neutral theory of biodiversity and biogeography. Princeton, NJ: Princeton University Press.Google Scholar
  45. Inkpen, S. A. (2017). Are humans disturbing conditions in ecology? Biology and Philosophy, 32, 51–71.Google Scholar
  46. Kareiva, P., & Mariver, M. (2012). What is conservation science? BioScience, 62(11), 962–969.Google Scholar
  47. Kingma, E. (2007). What is it to be healthy? Analysis, 67(294), 128–133.Google Scholar
  48. Kitcher, P. (1990). The division of cognitive labor. Journal of Philosophy, 87, 5–22.Google Scholar
  49. Kitcher, P. (1993). The advancement of science. New York: Oxford University Press.Google Scholar
  50. Larson, B. M. H. (2005). The war of the roses: Demilitarizing invasion biology. Frontiers in Ecology and the Environment, 3(9), 495–500.Google Scholar
  51. Lodge, D., & Shrader-Frechette, K. (2003). Nonindigenous species: Ecological explanation, environmental ethics, and public policy. Conservation Biology, 17(1), 31–37.Google Scholar
  52. Long, G. (2011). Disagreement and responses to climate change. Environmental Values, 20(4), 503–525.Google Scholar
  53. Longino, H. (1990). Science as social knowledge: Values and objectivity in scientific inquiry. Princeton: Princeton University Press.Google Scholar
  54. Longino, H. (1996). Cognitive and non-cognitive values in science: Rethinking the dichtomy. In L. H. Nelson & J. Nelson (Eds.), Feminism, science, and the philosophy of science (pp. 39–58). Dordrecht: Kluwer.Google Scholar
  55. MacDougall, A. S., & Turkington, R. (2005). Are invasive species the drivers or passengers of change in degraded ecosystems? Ecology, 86(1), 42–55.Google Scholar
  56. Moore, G. E. (1903). Principia ethica. Cambridge: Cambridge University Press.Google Scholar
  57. Murcia, C., Aronson, J., Kattan, G. H., Moreno-Mateos, D., Dixon, K., & Simberloff, D. (2014). A critique of the ‘novel ecosystem’ concept. Trends in Ecology & Evolution, 29(10), 548–553.Google Scholar
  58. National Invasive Species Council (NISC), Beck, G., Zimmerman, K., Schardt, J. D., Stone, J., Lukens, R. R., Reichard, S., et al. (2006). Invasive species defined in a policy context: Recommendations from the federal invasive species advisory committee. Invasive Plant Science and Management, 1(4), 414–421.Google Scholar
  59. Oreskes, N., & Conway, E. M. (2010). Merchants of doubt: How a handful of scientists obscured the truth on issues from tobacco smoke to global warming. New York: Bloomsbury Press.Google Scholar
  60. Pearce, F. (2015). The new wild: Why invasive species will be nature’s salvation. Boston, MA: Beacon Press.Google Scholar
  61. Purdy, J. (2015). Environmentalism’s racist history. The New Yorker, August 13. Accessed October 3, 2018.
  62. Raffles, H. (2011). Mother nature’s melting pot. New York Times, April 2, 2011.Google Scholar
  63. Rawls, J. (1996). Political liberalism. New York: Columbia University Press.Google Scholar
  64. Ricciardi, A., Blackburn, T. M., Clarton, J. T., Dick, J. T. A., Hulme, P. E., Iacarella, J. C., et al. (2017). Invasion science: A horizon scan of emerging challenges and opportunities. Trends in Ecology & Evolution, 34, 464–474.Google Scholar
  65. Ricciardi, A., & Ryan, R. (2018a). The exponential growth of invasive species denialism. Biological Invasions, 20, 549–553.Google Scholar
  66. Ricciardi, A., & Ryan, R. (2018b). Invasive species denialism revisited: Response to Sagoff. Biological Invasions, 20(10), 2731–2738.Google Scholar
  67. Russell, J. C., & Blackburn, T. M. (2017). The rise of invasive species denialism. Trends in Ecology & Evolution, 32(1), 3–6.Google Scholar
  68. Sagoff, M. (1999). What’s wrong with exotic species? Philosophy & Public Policy Quarterly, 19(4), 16–23.Google Scholar
  69. Sagoff, M. (2005). Do non-native species threaten the natural environment? Journal of Agricultural and Environmental Ethics, 18(3), 215–236.Google Scholar
  70. Sagoff, M. (2009a). Environmental harm: Political not biological. Journal of Agricultural and Environmental Ethics, 22, 81–88.Google Scholar
  71. Sagoff, M. (2009b). Who is the invader? Alien species, property rights, and the police power. Social Philosophy and Policy, 26(2), 26–52.Google Scholar
  72. Sagoff, M. (2018). What is invasion biology? Ecological Economics, 154, 22–30.Google Scholar
  73. Shamoo, A., & Resnik, D. (2015). Responsible conduct of research (3rd ed.). New York: Oxford University Press.Google Scholar
  74. Shrader-Frechette, K. (2001). Non-indigenous species and ecological explanation. Biology and Philosophy, 16, 507–519.Google Scholar
  75. Simberloff, D. (2003). Confronting introduced species: A form of xenophobia? Biological Invasions, 5, 179–192.Google Scholar
  76. Simberloff, D. (2004). Invasion biology. Critique of a pseudoscience. D.I. Theodoropoulos, Avvar Books, 2003. Ecological Economics, 48(3), 360–362.Google Scholar
  77. Simberloff, D. (2005a). Non-native species do threaten the natural environment! Journal of Agricultural and Environmental Ethics, 18, 595–607.Google Scholar
  78. Simberloff, D. (2005b). The politics of assessing risk for biological invasions: The USA as a case study. Trends in Ecology & Evolution, 20(5), 216–222.Google Scholar
  79. Simberloff, D. (2012). Nature, natives, nativism, and management: Worldviews underlying controversies in invasion biology. Environmental Ethics, 34, 5–25.Google Scholar
  80. Simberloff, D. (2013). Invasive species: What everyone needs to know. New York: Oxford University Press.Google Scholar
  81. Simberloff, D. (2014). Biological invasions: What’s worth fighting and what can be won? Ecological Engineering, 65, 112–121.Google Scholar
  82. Simberloff, D. (2015). Nature’s nature and the place of non-native species. Current Biology, 25, R588–R591.Google Scholar
  83. Simberloff, D., Martin, J., Genovesi, P., Maris, V., Wardle, D. A., Aronson, J., et al. (2013). Impacts of biological invasions: What’s what and the way forward. Trends in Ecology & Evolution, 28(1), 58–66.Google Scholar
  84. Simberloff, D., Souza, L., Nunez, M. A., Noelia Barrios-Garcia, M., & Bunn, W. (2012). The natives are restless, but not often and mostly when disturbed. Ecology, 93(3), 598–607.Google Scholar
  85. Simberloff, D., et al. (2011). Non-natives: 141 scientists object. Nature, 475, 36.Google Scholar
  86. Soulé, M. (1985). What is conservation biology? BioScience, 35, 737–744.Google Scholar
  87. Steele, K. (2012). The scientist qua policy advisor makes value judgment. Philosophy of Science, 79, 893–904.Google Scholar
  88. Subramaniam, B. (2001). The aliens have landed! Reflections on the rhetoric of biological invasions. Meridians, 2(1), 26–40.Google Scholar
  89. Takacs, D. (1996). The idea of biodiversity: Philosophies of paradise. Baltimore, MD: Johns Hopkins University Press.Google Scholar
  90. Theodoropoulos, D. I. (2003). Invasion biology: Critique of a pseudoscience. Blythe, CA: Avvar Books.Google Scholar
  91. Thompson, K. (2014). Where do camels belong? The story and science of invasive species. London: Profile Books.Google Scholar
  92. Van Driesche, R., Simberloff, D., Blossey, B., Causton, C., Hoddle, M., Marks, C., et al. (Eds.). (2016). Integrating biological control into conservation practice. Hoboken, NJ: Wiley.Google Scholar
  93. Van Kleunen, M., Dawson, W., Essl, F., Pergl, J., Winter, M., Weber, E., et al. (2015). Global exchange and accumulation of non-native plants. Nature, 525, 100–103.Google Scholar
  94. Warren, R. J., II, King, J. R., Tarsa, C., Haas, B., & Henderson, J. (2017). A systematic review of context bias in invasion biology. PLoS ONE, 12(8), e0182502.Google Scholar
  95. Webb, D. A. (1985). What are the criteria for presuming native status? Watsonia, 15, 231–236.Google Scholar
  96. Weisberg, M., & Muldoon, R. (2009). Epistemic landscapes and the division of cognitive labor. Philosophy of Science, 76(2), 225–252.Google Scholar
  97. Wilcove, D. S., Rothstein, D., Dubow, J., Phillips, A., & Losos, E. (1988). Quantifying threats to imperiled species in the United States. BioScience, 48, 607–615.Google Scholar
  98. Young, A. M., & Larson, B. M. H. (2011). Clarifying debates in invasion biology: A survey of invasion biologists. Environmental Research, 111, 893–898.Google Scholar

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Authors and Affiliations

  1. 1.Department of PhilosophyUniversity of TennesseeKnoxvilleUSA
  2. 2.Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleUSA

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