Skip to main content

Marsupial lions and methodological omnivory: function, success and reconstruction in paleobiology

Abstract

Historical scientists frequently face incomplete data, and lack direct experimental access to their targets. This has led some philosophers and scientists to be pessimistic about the epistemic potential of the historical sciences. And yet, historical science often produces plausible, sophisticated hypotheses. I explain this capacity to generate knowledge in the face of apparent evidential scarcity by examining recent work on Thylacoleo carnifex, the ‘marsupial lion’. Here, we see two important methodological features. First, historical scientists are methodological omnivores, that is, they construct purpose-built epistemic tools tailored to generate evidence about highly specific targets. This allows them to produce multiple streams of independent evidence and thus maximize their epistemic reach. Second, investigative scaffolding: research proceeds in a piece-meal fashion, information only gaining evidential relevance once certain hypotheses are well supported. I illustrate scaffolding in a discussion of the nature of functional ascription in paleobiology. Frequently, different senses of ‘function’ are not discriminated during paleobiological investigation—something which can mar adaptationist investigations of extant organisms. However, I argue that, due to scaffolding, conflating senses of ‘function’ can be the right thing to do. Coarse-grained functional hypotheses are required before it is clear what evidence could discriminate between more fine-grained ones. I draw on omnivory and scaffolding to argue that pessimists make a bad empirical bet. It is a bad idea to bet against the epistemic fortunes of such opportunistic and resourceful scientists, especially when we have reason to think we will systematically underestimate the amount of evidence ultimately available to them.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Notes

  1. Although, see Jeffares 2008.

  2. This is, on the face of it, a different kind of success than that which drives arguments about realism/anti-realism. That debate hinges on whether success at ‘saving the phenomena’, that is, empirical adequacy, provides reason to believe in successful theories’ posits. I am interested in how historical scientists generate the amount of knowledge that they do, given the difficulty of their investigative targets.

  3. Of course, the point of demarcation is to understand the success and failure of sciences, and so these discussions are related. However, I am not primarily interested in comparing historical to ahistorical science. Rather, I examine historical science on its own terms.

  4. Reconstructing past organisms is not the only, or even the central, business of paleobiology. More important is study of large-scale macroevolutionary patterns revealed in the fossil record.

  5. For instance, Carey et al. (2011) describes a trackway assemblage from Victoria which may contain a few traces of T. carnifex, however this is quite speculative.

  6. The thought that T. carnifex was arboreal can be traced to Wells and Nichol (1977)’s morphological study. My philosophical point does not rely on which hypothesis about T. carnifex’s locomotive method turns out to be the most plausible: indeed, if I am right about scaffolding, we ought to expect debates like this to drive further discovery.

  7. Recently, Wells et al. (2009) have argued that T. carnifex was a climber after all, pointing to pedal morphology. As they discuss, heavy animals like bears and gorillas can certainly climb trees. This misses the mark: Finch and Freedman’s complaint is not that something as large as T. carnifex couldn’t climb a tree, but that it couldn’t climb a tree in a koala-like manner. Especially in light of Wroe et al. (1999)’s weight estimates, I think this fairly convincing.

  8. See Thomason (1991) for extended discussion of the idealizations made, and their justifications (in particular, estimations using beam-theory are contrasted with independent in vivo tests of bite force).

  9. The centroid of a two dimensional object is (informally) the point at which it would, were it a cardboard cut-out, balance perfectly on the tip of a pencil.

  10. Leah Schwartz has pointed out to me that things are not as cut and dry as they appear: whether such out-competition really occurred is difficult to establish. I don’t think this undermines the philosophical point of the discussion, however.

  11. However, Bennett and Goswami (2013) have since produced further evidence of less disparity across marsupial skulls than placental skulls.

  12. ‘Bracketed’, in reference to ‘phylogenetic bracketing’.

  13. Thanks to Brett Calcott for suggesting the inclusion of the environment. Although the bracketed models considered in T. carnifex reconstruction do not index inferences to environments, some do. Particularly in cases where evolutionary convergences are exploited to support adaptationist hypotheses (see Currie 2013).

  14. For instance, there are many ways of getting around trade-offs and this can make optimality models misleading. Erickson et al. (2004) have argued that T. rex had two distinct ontogenetic stages: a juvenile stage characterized by fast running speeds and feathers, and a slow, featherless adult packing a major bite. They speculate that the animal hunted in packs, the smaller animal catching and harrying prey, allowing their mature conspecifics to catch up for the kill. If there is a tradeoff between size and speed in Tyrannosaurids, this is a way of solving it: although I doubt it would be represented in an optimality model.

  15. See, for example, Brandon (2013), Amundson and Lauder (1994), Griffiths (2006), Cummins (1975), Preston (1998).

  16. A referee points out that that, if pessimists are right and many facts about the past will remain unknown to us, then this defence of functional conflation will be much stronger. There is, then, something of a tension between my argument against pessimism, and my argument that a lack of information about the past can justify conflation. If the former argument is right, the scope of the latter argument will decrease. I don’t see this tension as problematic: even the most optimistic attitude to the historical sciences ought to allow that, at least sometimes, the past will remain hidden—and in those cases, some conflation might be allowable.

References

  • Amundson R, Lauder G (1994) Function without purpose. Biol Philos 9(4):443–469

    Article  Google Scholar 

  • Beatty J, Desjardins E (2009) Natural selection and history. Biol Philos 24(2):231–246

    Article  Google Scholar 

  • Bennett V, Goswami A (2013) Statistical support for the hypothesis of developmental constraint in marsupial skull evolution. BMC Biol 11:52

    Article  Google Scholar 

  • Brandon R (2013) A general case for functional pluralism. In: Huneman P (ed) Functions: selection and mechanisms. Springer, New York, pp 97–104

    Chapter  Google Scholar 

  • Carey SP, Camens AB, Cupper ML, Grün R, Hellstrom JC, McKnight SW et al (2011) A diverse Pleistocene marsupial trackway assemblage from the Victorian Volcanic Plains, Australia. Quat Sci Rev 30(5):591–610

    Article  Google Scholar 

  • Christian A, Dzemski G (2011) Neck posture in sauropods. In: Klein N, Remes K, Gee CT, Sander PM (eds) Biology of the sauropod dinosaurs, understanding the life of giants. Indiana University Press, Bloomington, pp 251–262

    Google Scholar 

  • Cleland CE (2011) Prediction and explanation in historical natural science. Br J Philos Sci 62:551–582

    Article  Google Scholar 

  • Cummins R (1975) Functional analysis. J Philos 72:741–764

    Article  Google Scholar 

  • Currie A (2013) Convergence as evidence. Br J Philos Sci 64(4):763–786

  • Currie A (2014) Venomous dinosaurs and rear-fanged snakes: homology and homoplasy characterized. Erkenntnis 79(3):701–727

  • Currie A (under review) Hot-blooded gluttons: how exploiting dependencies between past events increases our epistemic access to them

  • Davis D (1964) The giant panda: a morphological study of evolutionary mechanisms. Fieldiana Zool Mem 3:1–339

    Google Scholar 

  • Erickson GM, Makovicky PJ, Currie PJ, Norell MA, Yerby SA, Brochu CA (2004) Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs. Nature 430:772–775

  • Finch M, Freedman L (1988) Functional morphology of the limbs of Thylacoleo carnifex. Aust J Zool 36:251–272

    Article  Google Scholar 

  • Forber P (2009) Spandrels and a pervasive problem of evidence. Biol Philos 24(2):247–266

    Article  Google Scholar 

  • Forber P, Griffith E (2011) Historical reconstruction: gaining epistemic access to the deep past. Philos Theory Biol 3:1–19

  • Goswami A, Milne N, Wroe S (2010) Biting through constraints: cranial morphology, disparity and convergence across living and fossil carnivorous mammals. Proc R Soc B 278:1831–1839

  • Gould SJ, Lewontin RC (1979) The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proc R Soc Lond Ser B Biol Sci 205(1161):581–598

    Article  Google Scholar 

  • Griffiths P (1996) The historical turn in the study of adaptation. Br J Philos Sci 47:511–532

    Article  Google Scholar 

  • Griffiths P (2006) Function, homology, and character individuation. Philos Sci 73(1):1–25

    Article  Google Scholar 

  • Jeffares B (2008) Testing times: regularities in the historical sciences. Stud Hist Philos Sci Part C 39(4):469–475

    Article  Google Scholar 

  • Jeffares B (2010) Guessing the future of the past. Biol Philos 25(1):125–142

    Article  Google Scholar 

  • Kosso P (2001) Knowing the past: philosophical issues of history and archaeology. Humanity books

  • Levy A, Currie A (2014) Model organisms are not (theoretical) models. Br J Philos Sci. doi:10.1093/bjps/axt055

    Google Scholar 

  • Lewontin RC (1998) The evolution of cognition: questions we will never answer. In: Scarborough D, Sternberg S (eds) An invitation to cognitive science, vol 4: methods, models, and conceptual issues. MIT Press, Cambridge, MA

  • Martin J, Martin-Rolland V, Frey E (1998) Not cranes or masts, but beams: the biomechanics of sauropod necks. Oryctos 1:113–120

    Google Scholar 

  • Mitchell SD (2002) Integrative pluralism. Biol Philos 17(1):55–70

    Article  Google Scholar 

  • Mitchell SD (2003) Biological complexity and integrative pluralism. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Potochnik Angela (2009) Optimality modeling in a suboptimal world. Biol Philos 24(2):183–197

    Article  Google Scholar 

  • Powell R (2012) Convergent evolution and the limits of natural selection. Eur J Philos Sci 2(3):355–373

    Article  Google Scholar 

  • Preston B (1998) Why is a wing like a spoon? A pluralist theory of function. J Philos 95(5):215–254

    Article  Google Scholar 

  • Ruxton G, Wilkinson D (2011) The energetics of low browsing in sauropods. Biol Lett 7(5):779–781

    Article  Google Scholar 

  • Seymour RS (2009) Raising the sauropod neck: it costs more to get less. Biol Lett 5:317–319

    Article  Google Scholar 

  • Thomason JJ (1991) Cranial strength in relation to estimated biting forces in some mammals. Can J Zool 69:2326–2333

    Article  Google Scholar 

  • Tucker A (2004) Our knowledge of the past: a philosophy of historiography. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Turner D (2005) Local underdetermination in historical science. Philos Sci 72(1):209–230

    Article  Google Scholar 

  • Turner D (2007) Making prehistory: historical science and the scientific realism debate. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Turner D (2009) Beyond detective work: empirical testing in paleontology. In: Sepkoski D, Ruse M (eds) The paleobiological revolution: essays on the growth of modern paleontology. University of Chicago Press, Chicago

    Google Scholar 

  • Turner D (2011) Paleontology: a philosophical introduction. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Wells R, Nichol B (1977) On the manus and pes of Thylacoleo-carnifex marsupialia. Trans R Soc S Aust 101:139–152

    Google Scholar 

  • Wells R, Murray P, Bourne S (2009) Pedal morphology of the marsupial lion Thylacoleo carnifex. J Vertebr Paleontol 29(4):1335–1340

    Article  Google Scholar 

  • Werdelin L (1988) Circumventing a constraint: the case of Thylacoleo (Marsupialia, Thylacoleonidae). Aust J Zool 36:565–571

    Article  Google Scholar 

  • Wouters A (1995) Viability explanation. Biol Philos 10(4):435–457

    Article  Google Scholar 

  • Wroe S, Myers TJ, Wells RT, Gillespie A (1999) Estimating the weight of the Pleistocene marsupial lion, Thylacoleo carnifex: implications for the ecomorphology of a marsupial super-predator and hypotheses of impoverishment of Australian marsupial carnivore faunas. Aust J Zool 47:489–498

    Article  Google Scholar 

  • Wroe S, McHenry C, Thomason J (2005) Bite club: comparative bite force in big biting mammals and the prediction of predatory behaviour in fossil taxa. Proc R Soc B 272:619–625

    Article  Google Scholar 

  • Wylie A (1985) The reaction against analogy. Adv Archaeol Method Theory 8:63–111

  • Wylie A (1999) Rethinking unity as a “working hypothesis” for philosophy of science: how archaeologists exploit the disunities of science. Perspect Sci 7(3):293–317

    Article  Google Scholar 

  • Wylie A (2011) Critical distance: stabilising evidential claims in archaeology. In: Dawid P, Twining W, Vasilaki M (eds) Evidence, inference and enquiry. Oup/British Academy, London

Download references

Acknowledgments

This paper was presented at the 7th Munich-Sydney-Tilburg philosophy of science conference, “Evolutionary Thinking”, as well as at Calgary and Otago Universities. I’m grateful to these audiences for their feedback. Maureen O’Malley, Leah Schwartz and Brett Calcott read drafts and provided incisive, constructive comments. The paper also benefitted greatly from the generous input of two anonymous referees.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Adrian Currie.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Currie, A. Marsupial lions and methodological omnivory: function, success and reconstruction in paleobiology. Biol Philos 30, 187–209 (2015). https://doi.org/10.1007/s10539-014-9470-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10539-014-9470-y

Keywords

  • Historical science
  • Paleobiology
  • Function
  • Methodology
  • Scientific success
  • Reconstruction