When Mechanisms Are Not Enough: The Origin of Eukaryotes and Scientific Explanation

  • Roger Deulofeu
  • Javier Suárez
Part of the European Studies in Philosophy of Science book series (ESPS, volume 9)


The appeal to mechanisms in scientific explanation is commonplace in contemporary philosophy of science. In short, mechanists argue that an explanation of a phenomenon consists of citing the mechanism that brings the phenomenon about. In this paper, we present an argument that challenges the universality of mechanistic explanation: in explanations of the contemporary features of the eukaryotic cell, biologists appeal to its symbiogenetic origin and therefore the notion of symbiogenesis plays the main explanatory role. We defend the notion that symbiogenesis is non-mechanistic in nature and that any attempt to explain some of the contemporary features of the eukaryotic cell mechanistically turns out to be at least insufficient and sometimes fails to address the question that is asked. Finally, we suggest that symbiogenesis is better understood as a pragmatic scientific law and present an alternative non-mechanistic model of scientific explanation. In the model we present, the use of scientific laws is supposed to be a minimal requirement of all scientific explanations, since the purpose of a scientific explanation is to make phenomena expectable. Therefore, this model would help to understand biologists’ appeal to the notion of symbiosis and thus is shown to be better, for the case under examination, than the mechanistic alternative.


Scientific explanation Mechanistic explanation Scientific laws Eukaryotic cell Symbiogenesis Symbiosis 



Different versions of this paper were presented at the VIII Meeting of the Spanish Society for Logic, Methodology and Philosophy of Science (University of Barcelona, 2015) and the III Conference of the German Society for the Philosophy of Science (University of Düsseldorf, 2016). We would like to thank all the participants for their helpful comments and suggestions. We would also like to thank Thomas Bonnin, Mark Canciani, José Díez, John Dupré, Çağlar Karaca, Adrian Stencel and an anonymous referee, who read previous versions of this paper and made helpful comments and suggestions. Finally, the Spanish Ministry of Economy and Competitiveness (FFI2016-767999-P) and the Fundación Bancaria la Caixa are formally acknowledged for their economic support.


  1. Alleva, K., J. Díez, and L. Federico. 2017. Models, theory structure and mechanisms in biochemistry: The case of allosterism. Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 63: 1–14.CrossRefGoogle Scholar
  2. Archibald, J. 2014. One plus one equals one: Symbiosis and the evolution of complex life. Oxford: Oxford University Press.Google Scholar
  3. ———. 2015. Endosymbiosis and eukaryotic cell evolution. Current Biology 25: R911–R921.CrossRefGoogle Scholar
  4. Audesirk, T., G. Audesirk, and B.E. Byers. 2008. Biology: Life on earth. Hoboken: Pearson Education.Google Scholar
  5. Balzer, W., C.U. Moulines, and J.D. Sneed. 2012. An architectonic for science: The structuralist program. Vol. 186. Dordrecht: Springer.Google Scholar
  6. Bechtel, W. 2006. Discovering cell mechanisms: The creation of modern cell biology. Cambridge University Press.Google Scholar
  7. Bechtel, W. 2011. Mechanism and biological explanation. Philosophy of Science 78 (4): 533–557.CrossRefGoogle Scholar
  8. Bechtel, W., and A. Abrahamsen. 2005. Explanation: A mechanist alternative. Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 36 (2): 421–441.CrossRefGoogle Scholar
  9. Bechtel, W., and R.C. Richardson. 1993. Discovering complexity: Decomposition and localization as scientific research strategies. Cambridge, MA: The MIT Press.Google Scholar
  10. Brandon, R.N. 1997. Does biology have laws? The experimental evidence. Philosophy of Science 64: S444–S457.CrossRefGoogle Scholar
  11. Cavalier-Smith, T. 1989. Archaebacteria and Archezoa. Nature 339: 100–101.CrossRefGoogle Scholar
  12. ———. 2013. Symbiogenesis: Mechanisms, evolutionary consequences, and systematic implications. Annual Review of Ecology, Evolution, and Systematics 44: 145–172.CrossRefGoogle Scholar
  13. Craver, C.F. 2006. When mechanistic models explain. Synthese 153 (3): 355–376.CrossRefGoogle Scholar
  14. ———. 2007. Explaining the brain. New York: Clarendon Press.CrossRefGoogle Scholar
  15. ———. 2008. Physical law and mechanistic explanation in the Hodgkin and Huxley model of the action potential. Philosophy of Science 75: 1022–1033.CrossRefGoogle Scholar
  16. Craver, C.F., and M.I. Kaiser. 2013. Mechanisms and laws: Clarifying the debate. In Mechanism and causality in biology and economics, ed. H.K. Chao, S.T. Chen, and R.L. Millstein, vol. 3, 125–145. New York: Springer.CrossRefGoogle Scholar
  17. Darden, L., and C.F. Craver. 2002. Strategies in the interfield discovery of the mechanism of protein synthesis. Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 33 (1): 1–28.CrossRefGoogle Scholar
  18. Deulofeu, R., and J. Suárez. 2015. On the explanatory character of Margulis’ theory of the origin of the eukaryotic cell. In Proceedings of the VIII Meeting of the Spanish society for logic, methodology and philosophy of science, ed. J.A. Díez, M. García-Carpintero, J. Martínez, and S. Oms, 276–280. Barcelona: Universitat de Barcelona.Google Scholar
  19. Díez, J.A. 2002. Explicación, unificación y subsunción. In Diversidad de la explicación científica, ed. W.J. González, 73–96. Barcelona: Ariel.Google Scholar
  20. ———. 2014. Scientific w-explanation as ampliative, specialised embedding: a neo-hempelian account. Erkenntnis 79: 1413–1443.CrossRefGoogle Scholar
  21. Dolan, M.F. 2013. Endosymbiosis and the origin of eukaryotes. In Evolution from the Galapagos: Two centuries after Darwin, ed. G. Trueba and C. Montúfar, 125–128. New York: Springer.CrossRefGoogle Scholar
  22. Douglas, A.E. 2010. The symbiotic habit. Oxford: Princeton University Press.Google Scholar
  23. Glennan, S. 1996. Mechanisms and the nature of causation. Erkenntnis 44 (1): 49–71.CrossRefGoogle Scholar
  24. ———. 2002. Rethinking mechanistic explanation. Philosophy of Science 69 (S3): S342–S353.CrossRefGoogle Scholar
  25. Gruber-Vodicka, H.R., U. Dirks, N. Leisch, C. Baranyi, K. Stoecker, S. Bulgheresi, N.R. Heindl, M. Horn, C. Lott, A. Loy, M. Wagner, and J. Ott. 2011. Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms. PNAS of the United States of America 108 (29): 12078–12083.CrossRefGoogle Scholar
  26. Hempel, C.G. 1965. Aspects of scientific explanation and other essays in the philosophy of science. New York: Free Press.Google Scholar
  27. Hempel, C., and P. Oppenheim. 1948. Studies in the logic of explanation. Philosophy of Science 15 (2): 135–175.CrossRefGoogle Scholar
  28. Kuhn, T.S. 1970. Second thoughts on paradigms. In The structure of scientific theories, ed. F. Suppe, 459–482. Urbana: University of Illinois Press.Google Scholar
  29. Leuridan, B. 2010. Can mechanisms really replace laws of nature? Philosophy of Science 77 (3): 317–340.CrossRefGoogle Scholar
  30. Machamer, P., L. Darden, and C.F. Craver. 2000. Thinking about mechanisms. Philosophy of Science 67 (1): 1–25.CrossRefGoogle Scholar
  31. Margulis, L. 1970. Origin of eukaryotic cells: Evidence and research implications. New Haven: Yale University Press.Google Scholar
  32. Martin, W.F., M. Roettger, T. Kloesges, T. Thiergart, C. Woehle, S. Gould, and T. Dagan. 2012. Modern endosymbiotic theory: Getting lateral gene transfer into the equation. Journal of Ensocytobiosis and Cell Research 23: 1–5.Google Scholar
  33. Martin, W.F., S. Garg, and V. Zimorski. 2015. Endosymbiotic theories for eukaryote origin. Philosophical Transactions of the Royal Society B 370: 20140330.CrossRefGoogle Scholar
  34. Mitchell, S.D. 1997. Pragmatic laws. Philosophy of Science 64: S468–S479.CrossRefGoogle Scholar
  35. ———. 2000. Dimensions of scientific law. Philosophy of Science 67 (2): 242–265.CrossRefGoogle Scholar
  36. ———. 2003. Biological complexity and integrative pluralism. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  37. Moran, N., and D.B. Sloan. 2015. The hologenome concept: Helpful or hollow? PLoS Biology 13 (12): e1002311.CrossRefGoogle Scholar
  38. Nicholson, D.J. 2012. The concept of mechanism in biology. Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 43 (1): 152–163.CrossRefGoogle Scholar
  39. O’Malley, M. 2010. The first eukaryote cell: An unfinished history of contestation. Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 41 (3): 212–224.CrossRefGoogle Scholar
  40. Raff, R.A., and H.R. Mahler. 1972. The non symbiotic origin of mitochondria. Science 177: 575–582.CrossRefGoogle Scholar
  41. Roe, S.M., and B. Baumgaertner 2016. Extended mechanistic explanations: Expanding the current mechanistic conception to include more complex biological systems. Journal for General Philosophy of Science 48: 517–534Google Scholar
  42. Sagan, L. 1967. On the origin of mitosing cells. Journal of Theoretical Biology 14: 225–274.CrossRefGoogle Scholar
  43. Sapp, J. 2010. Saltational symbiosis. Theory Biosciences 129: 125–133.CrossRefGoogle Scholar
  44. Spang, A., J.H. Saw, S.L. Jørgensen, K. Zaremba-Niedzwiedzka, J. Martijn, A.E. Lind, R. van Eijk, C. Schleper, L. Guy, and T.J.G. Ettema. 2015. Complex Archaea that bridge the gap between prokaryotes and eukaryotes. Nature 521: 173–179.CrossRefGoogle Scholar
  45. Stearns, S.C., and R.F. Hoekstra. 2000. Evolution. An introduction. Oxford: Oxford University Press.Google Scholar
  46. Uzzel, T., and C. Spolsky. 1974. Mitochondria and plastids as endosymbionts: A revival of special creation? American Scientist 62: 334–343.Google Scholar
  47. Williams, T.A., and T.M. Embley. 2015. Changing ideas about eukaryotic origins. Philosophical transactions of the Royal Society of London. Series B 370: 20140318.CrossRefGoogle Scholar
  48. Woodward, J. 1997. Explanation, invariance, and intervention. Philosophy of Science 64: S26–S41.CrossRefGoogle Scholar
  49. ———. 2000. Explanation and invariance in the special sciences. The British Journal for the Philosophy of Science 51 (2): 197–254.CrossRefGoogle Scholar
  50. ———. 2003. Making things happen. New York: Oxford University Press.Google Scholar
  51. ———. 2017. Scientific explanation. In The Stanford encyclopedia of philosophy, ed. E.N. Zalta.

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of PhilosophyUniversity of BarcelonaBarcelonaSpain
  2. 2.Department of Sociology, Philosophy and AnthropologyUniversity of ExeterExeterUK

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