Lessons from Slijper’s Goat: On the Convergence of Classical and Modern Biology

1. Lessons from Slijper’s Goat:On the Convergence of Classical and Modern Biology James Barham University of Notre Dame and Institute for the Study of Nature June 12, 2008

2. I. The Reality of Functional Stability • Recall our definition of life: Life is the inherent capacity of a certain kind of material system for spontaneous activity resulting in the functional stability of the system • Two questions: • Is “functional stability” real, or merely a kind of mental construct that human beings cannot help projecting onto living things? • If it is real, how is it physically possible?

3. A. Slijper’s Goat as a Model Organism • Throughout the history of science, certain organisms have come to exemplify general theories or attitudes toward life: • 18th c.—Trembley’s “polyp” (freshwater hydra) (vitalism) • 19th c.—Darwin’s finches (natural selection) • 20th c.—Morgan’s fruitflies (Drosophila melanogaster) (genetics) • 21st c.—Slijper’s goat (functional realism, emergentism)?

4. B. The Standard Reductionist Account of Function • According to the standard account, the functional (teleological) aspects of living things can be fully reduced to physical (“efficient”) causation, with the help of two bodies of theory: • Cybernetic control • Natural Selection • Slijper’s goat is important because it is a vivid demonstration of the inadequacy of the standard account

5. C. Story of Slijper’s Goat • E.J. Slijper (1907–1968) was a professor of veterinary anatomy at the University of Utrecht in the Netherlands (later Professor of Zoology at the University of Amstedam) (Moore 1969) • In 1939, Slijper received a three-month-old goat born without forelegs (Slijper 1942) • Under his care, the goat learned to locomote by means of an upright posture and kangaroo-like bipedal gait • Upon its death, autopsy revealed extensive remodeling of the muscles and skeleton, resembling those of rodents and marsupials that normally adopt a bipedal gait.

6. D. Faith the Dog • A contemporary case similar to Slijper’s goat: Faith the Dog • http://www.youtube.com/watch?v=aZsV4R3XJKk

7. E. The Undisputed Facts Relating to Slijper’s Goat • Locomotion is a crucial function in animals, normally constructed soon after birth • The construction of normal quadrupedal gait in the goat was severely perturbed due to the birth defect • The organism of the goat compensated for this perturbation by spontaneously constructing the radically different, bipedal gait • At a minimum, this construction of bipedal gait involved the major restructuring of three organ systems: • Musculature • Skeleton • Nervous system • The construction of bipedal gait was the result both of conscious striving (it required effort and learning), and also of non-conscious compensatory response throughout the organism

8. F. West-Eberhard’s Interpretation • West-Eberhard (2005) invokes the case of Slijper’s goat with a view to revising our understanding of evolution • The idea is that Slijper’s goat is a more extreme (and thus clearer) example of a normal and perfectly general phenomenon • Her claim is that all evolutionary change begins as “phenotypic accommodation,” meaning a compensatory response to perturbation, like that displayed by Slijper’s goat, leading to an adaptive innovation, like the bipedal gait

9. G. Phenotypic Accommodation and Evolution • Phenotypic accommodation is made possible by what she calls “developmental plasticity,” where “development” is understood broadly to include the ability of both the physical structure and the behavior of the organism to compensate for perturbation, both pre- and post-partum • Adaptive innovations constructed through the normal process of phenotypic accommodation then become genetically “fixed” (“genetic accommodation”), leading to permanent evolutionary change • The extent of genetic accommodation is highly controversial

10. H. Conceptual Priority of Phenotypic Accommodation • Nevertheless, phenotypic accommodation should not be controversial • Not only can we observe it in a case like Slijper’s goat, it also has conceptual priority within the framework of the theory of natural selection • A genetic change can only lead to a phenotypic change by the process of development, broadly construed • Adaptive innovations must first be developmentally constructed before they can be subjected to natural selection • Therefore, phenotypic accommodation is conceptually prior to natural selection

11. I. Note on Terminology • A number of different terms are found in the literature to refer to what West-Eberhard calls “phenotypic accommodation”: • Plasticity • Robustness • Adaptability • Useful distinctions among these ideas can be made for various purposes • However, for our purposes, the main point is that when a perturbation occurs within a living system, compensatory changes spontaneously occur in order to restore function and preserve life • This capacity for adaptive compensation is what we have been calling the “functional stability” of living things

12. J. Our Interpretation: Functional Stability Is Basic • Slijper’s goat shows that functional stability is objectively real in the sense of being “kickable”: perturbations lead to observable compensations • Furthermore, this case makes it obvious that this capacity cannot be explained on the basis of genes • This example also helps to make it clear that far from being reduced by natural selection, functional stability is presupposed by that theory • Not only is functional stability demonstrably real, and not only is it unreduced—it is the foundation upon which evolutionary theory tacitly rests

13. II. Why Teleoreductionism Fails • These are some rather sweeping claims • Let us now slow down a little bit and do some conceptual work with the phenomenon of functional stability, or what I shall now call “immanent teleology,” and the claims of mainstream reductionism

14. A. Teleoelimination and Teleoreduction • “Teleoelimination” is the claim that there is no such thing as immanent teleology • Flies in the face of both biological practice and common sense • “Teleoreduction” is the claim that immanent teleology is “nothing but” mechanistic processes of cybernetic control put in place by natural selection • Somewhat more plausbile

15. B. The Concept of Teleofunction • The word “function” is used in various ways, so let us say “teleofunction” to be clear about our claim that functional stability is a form of immanent teleology • Given a pair of events A and B with temporal ordering such that A = earlier (“cause”) and B = later (“effect”), for a causal relation between A and B to count as a teleofunction, there must exist a (partial) determination of B by A (A  B), but also a (partial) determination of A by B (A B) • In this case, A = “means” and B = “end” • Absent such (partial) determination of the temporally prior means by the temporally later end (A B), there is no teleofunction (final causation).

16. C. The Problem of Backwards Causation • All of life seems to operate according to the means-end logic of teleofunction; certainly, it is obvious that a very great deal of our own human experience takes this form • However, the standard account of biology denies that teleofunction is objectively real; it is considered at best a necessary illusion due to human cognitive defects • One great obstacle to accepting teleofunction at face value is understanding how it could be possible • On the face of it, teleofunction seems to require a future state of affairs to exert causal influence upon a present state of affairs: But how could this be? • This is the problem of so-called “backwards causation”

17. D. Representations Are No Help • One standard way of responding to the backwards causation problem is to invoke representations • The idea is that it is not a particular future state of the world that influences the present, but rather a model or “representation” of that state that already exists • However, while this seems to work for animals with brains (which is where representations are supposed to be located), it does not help with the general problem of functional stability, which is found in all living things • Moreover, it does not really work for animals with brains, either; let us see why

18. E. The Problem of Normativity • Representation is a normative concept; that is to say, it constitutes a criterion or standard according to which actions are judged right or wrong • For example, to say that the word “cat” represents a cat is to say that “cat” is supposed to mean a cat, and not some other animal • To utter the word “cat” (to an English speaker) while intending to represent a dog is to make a mistake • But there is no such thing as success or failure in physics and chemistry; matter just does what it must do, it is never right or wrong • Therefore, a representation is not a purely physical thing; it already embodies an aspect of the problem of teleofunction, and so cannot solve it

19. F. Goal, Norm, and Value • Another way of looking at teleofunction is to notice that a goal-state is a special or preferred state of a system • It is this specialness or preference that is the heart of the problem • A preferred state of a system has value for the system; that is, realizing the preferred state is good for the system, and failing to do so is bad • It is the goodness of preferred states that underlies the normativity of the means-end logic of teleofunction; the means are right insofar as the state they produce (the end) is good • In short, teleology, normativity, and axiology are a single problem-complex

20. G. The Failure of Teleoreduction—Cybernetic Control • The two forms of teleoreduction—cybernetic control and natural selection—both fail for the same reason: • They have no conceptual resources for explaining in non-normative terms why one particular state of a system should be privileged over others as the preferred state • The concept of cybernetic control presupposes an external agent who determines what counts as the preferred state of the system • The thermostat on my home heating system does not care if it is keeping the temperature of my house at the correct setting • It is I who determine what counts as the correct temperature, in relation to which the thermostat is judged as working properly or improperly

21. H. The Failure of Teleoreduction—Natural Selection • The theory of natural selection likewise presupposes value and normativity • It simply assumes that survival is the preferred state for organisms • Means (traits) that are (relatively) successful at realizing their functional ends are the ones “selected”; it is not “selection” that makes means capable of realizing their ends • Selection as such has no magic power to transform a physical state into a normative preferred state, as shown by the Swampman thought experiment (Davidson 2001)

22. I. Backwards Causation Again • But if teleoreduction fails, what is the solution? • The problem of backwards causation is a genuine one • After all, surely the future as such does not have any causal influence upon the present • One solution is to see that “backwards causation” is ambiguous between: • (a) the idea that a non-actual state of a system can causally influence an actual state (which is essential to the idea of teleofunction); and • (b) the idea that the future is in some sense actual (as on certain “block-universe” interpretations of time), and by virtue of this actuality may causally influence the past

23. J. Preferred States as Virtual States • To solve the problem of backwards causation, we have merely to reject the idea that the future is actual in any sense at all • This affirms the reality of the flow of time, which is anyhow desirable on realist grounds • Since, on this interpretation, the non-actual state of a teleofunction (the end) that causally influences the actual state (the means) is not the future as such, let us give it another name: • Let us call it a virtual state • Therefore, according to this idea, preferred states of teleofunctions are virtual states

24. K. What Is a Virtual Preferred State of a Teleofunction? • The question is, then: Can we give the concept of a virtual preferred state of a teleofunction a plausible scientific interpretation? • The answer is Yes • Example: The notion of a high-dimensional phase-space attractor incorporates a notion of virtuality that some have suggested may be useful for modeling the preferred state of teleofunctions (Delattre 1986; Yates 1994) • In the final section, let us see how this idea can be put together with ideas of ontological emergence to provide us with an alternative, realist view of the strange functional stability of life

25. III. Toward a Teleorealist View of Life • The view of life I wish to sketch briefly here might be called “teleorealist”: • That is, it views the immanent teleology associated with the functional stability of life as objectively real • We shall see that the key to a scientifically plausible teleorealism is viewing the cell within the framework of ontological emergence

26. A. The “Solid State Cell” • The first step toward understanding how functional stability can be physically possible is to realize that the cytoplasm is far from being in aqueous phase (Luby-Phelps 2000; Walleczek 2000) • On the contrary, it is so tightly packed with macromolecules that it has many properties in common with semi-solid phases of matter, such as: • liquid crystals (Ho et al. 1996); and • gels (Pollack 2001) • It has even been referred to recently as the “solid state cell” (McNiven 2003)

27. B. Condensed-Matter Physics of the Cell • Though speculative, a number of field-theoretic properties have been postulated for cytoplasmic structures, including: • Long-range coherence via the so-called “Fröhlich mechanism” (Del Giudice et al. 2005; Ho 1997) • Long-range collective action via functionally induced phase transitions (Pollack 2001) • “Quasi-particles” possibly governed by special conservation principles (Vitiello 2001)

28. C. How Does All This Help? • It is often pointed out that “self-organization” models that appeal to principles like dissipative structures fail to distinguish living matter from nonliving oscillators like hurricanes • Therefore, a natural question to ask is: How does condensed-matter physics help explain functional stability? • Tentative answer: Ontological emergence and scale-transcendent theoretical principles allow us to envision emergent quantum numbers and conservation principles specific to the living state of matter

29. D. The Master Speculation • We know that the functional stability of life cannot be explained purely in terms of ordinary physical principles such as minimum action • But perhaps functional stability could be understood in terms of some as-yet unknown conserved quantum numbers—say, corresponding to a “minimum effort principle” or “appropriateness” of means to end • Indeed, the faint outline of such an idea may already be visible in notions like “minimum frustration principle” and “topological charge conservation” that have been advanced in connection with models of the “functionally important motions” of proteins (Frauenfelder et al. 1991)

30. E. Conclusion • While this is all admittedly wildly speculative at present, nevertheless I think it goes to show that a general framework of ontological emergence gives us some useful resources for thinking about functional stability, and for taking a teleorealist view of life, generally

31. References • Davidson, D. (2001) “Knowing One’s Own Mind,” in idem, Subjective, Intersubjective, Objective. Oxford: Clarendon Press, pp. 15–38. • Delattre, P. (1986) “An Approach to the Notion of Finality According to the Concepts of Qualitative Dynamics,” in S. Diner, et al., eds., Dynamical Systems: A Renewal of Mechanism. Singapore: World Scientific, pp. 149–154. • Del Giudice, E., et al. (2005) “Coherent Quantum Electrodynamics in Living Matter,” Electromagnetic Biology and Medicine24: 199–210. • Frauenfelder, H., et al. (1991) “Physics from Proteins,” in L. Peliti, ed., Biologically Inspired Physics. New York: Plenum, pp. 1–14. • Ho, M.-W. (1997) “Towards a Theory of the Organism,” Integrative Physiological and Behavioral Science32: 343–363. • Ho, M.-W., et al. (1996) “Organisms as Polyphasic Liquid Crystals,” Bioelectrochemistry and Bioenergetics 41: 81–91.

32. References (cont.) • Luby-Phelps, K. (2000) “Cytoarchitecture and Physical Properties of Cytoplasm: Volume, Viscosity, Diffusion, Intracellular Surface Area,” in H. Walter, et al., eds., International Journal of Cytology, Vol. 192: Microcompartmentation and Phase Separation in Cytoplasm. San Diego: Academic Press, pp. 189–221. • McNiven, M.A. (2003) “The Solid State Cell,” Biology of the Cell94: 555–556. • Moore, J.C. (1969) “Obituary: Everhard Johannes Slijper, 1907–1968,” Journal of Mammalogy50: 386. • Pollack, G.H. (2001) Cells, Gels, and the Engines of Life. Seattle: Ebner & Sons. • Slijper, E.J. (1942) “Biologic-anatomical Investigations on the Bipedal Gait and Upright Posture in Mammals, with Special Reference to a Little Goat, born without Forelegs,” Proceedings of the Koninklijke Nederlandsche Akademie van Wetenschappen45: 288–295, 407–415.

33. References (cont.) • Vitiello, G. (2001) My Double Unveiled: The Dissipative Quantum Model of Brain. Amsterdam: John Benjmains. • Walleczek, J. (2000) “Changing Paradigms in Biomedicine: Implications for Future Research and Clinical Applications,” in idem, ed., Self-Organized Biological Dynamics and Nonlinear Control. Cambridge: Cambridge University Press, pp. 409–420. • West-Eberhard, M.J. (2005) “Phenotypic Accommodation: Adaptive Innovation Due to Developmental Plasticity,” Journal of Experimental Zoology (Molecular and Developmental Evolution)304B: 610–618. • Yates, F.E. (1994) “Order and Complexity in Dynamical Systems: Homeodynamics as a Generalized Mechanics for Biology,” Mathematical and Computer Modelling19(6–8): 49–74.