My previous post introduced concepts such as contingency and attraction. With this small essay I seek to open up some brick roads to matters of time and evolution, although you should really take a look at the articles I reference if you want to see how the "masters" do it.
Written for Philosophy of Biology (PHIL565 at the University of Calgary)
Professor: Marc Ereshefsky <http://people.ucalgary.ca/~ereshefs/>
Let us begin with Reichenbach’s common-cause principle. The principle states that simultaneous correlated events must have prior common causes (1). Specifically, for events x and y, when the probability of x and y occurring together is greater than the probability of x and y occurring independently of each other, there exists a “common-cause” z where it is true that: Pr(x/z) > Pr(x/~z), Pr(y/z > Pr(y/~z), Pr(x&y/z) = Pr(x/z) × Pr(y/z) and Pr(x&y/~z) = Pr(x/~x) × Pr(y/~z), where the symbol “Pr” denotes the probability of an event. It is upon this principle that, as Cleland argues (3), narratives about the distant past are generated. I will demonstrate that such narratives generated by the principle are insufficient for explaining why the states of affairs of the present are the way they are.
Under a physics worldview we ought to be able to observe the world around us and write a story about the dynamics of that system. When this story has been written, observers use those tools to make claims about events in the past. For example, that volcanoes erupt today and have an underlying model to explain their behaviour lends weight to the fact that perhaps volcanoes occurred in the past as well and share similar behaviour. However, in the history of time, there are some problems with the notion of extending such a worldview to the past. First, an observer cannot know the entire phase-space of the system that they are studying – this is a particularly difficult when you attempt to travel back in time. Second, since the phase space of a system is not prestatable, the asymmetry of overdetermination is rendered useless since it is never guaranteed that an observer can derive the common-cause because some set of effects occur. Now, keeping this in mind, suppose that there are no entailing laws, but enablement, for the evolution of the biosphere (2). By enablement, I mean that in an historical network, life emerges out of a web where the changing conditions of space and time “lock into” a moment such that novelty may arise, although not necessarily. That the conditions for something to materialize exist does not guarantee it will actually happen. For example, if a hostage is taken and a hero has a villain in a clear line of sights down their rifle, the hero is not guaranteed to take the shot – evolution could work the same way. Under this pretext, as the biosphere bubbles forth, the laws which are created over time to account for observable phenomena exist at the level of the phase-space. In turn, this phase-space has and will continue to evolve as the staggering diversity of variables, forms and niches are enabled in the biosphere. Since the physical phase-space is ever-evolving, any method we devise to generate our historical narrative will become contingent upon the axioms derived from those observations (à la Gödel’s incompleteness theorem). What I am not trying to say is that the world is unobservable or that an entailing laws worldview is entirely useless, but that the layer at which we generate narratives is grounded in the symmetries of such an axiomatic method, where the predictive power of the mathematical form our narrative takes is not restrained within the confines of a material reality. A mathematical form in this context becomes an operational description based on symbols, but will not actually inform us about what the specific components of events in the past are. Since these components are unknowable as ultimate ends to the effects leading to the present state of affairs, any historical narrative created as a result of our observation is rendered a correlation as opposed to having any one explanation as an overdetermining cause (e.g.; meteor impact versus pandemic in the extinction of dinosaurs).
With respect to this notion of symmetry, Longo and Montévil assert that objects in the physical world continually transform and renew their symmetries (called symmetry change) (4) which give rise to the variance seen at all scales of existence, lending an ear to concepts such as fractal geometry. Mathematically, as symmetries change over time, the object passes over a continuous landscape and enters into and breaks critical points, which could actually give rise to processes such as biological evolution itself under some conditions-N when given enough time (tending towards infinity). In the context of historical narratives, the breaking of critical points over time represents instances where a set of objects observed in the present may allow us to observe how a state of affairs came to be today, but since the domain of discourse used to study that phenomena depends on the state variables of the present, we ought not have confidence that the entailing laws of today necessarily constrain the symmetry of that object in the past. When applied to the common-cause principle, a “screener” cause z is a selection of the one of many such objects. Choosing just one is not only inadequate, but it provides no account for the self-similarity seen through time in the patterns of organization implied by the renewal and projection of objects whose symmetries evolve at such critical points.
1. Reichenbach, H. (1956). “The Direction of Time”, Berkeley, University of Los Angeles Press.
2. Longo, G., Montévil, M., Kauffman, SA. (2012). “No entailing laws, but enablement in the evolution of the biosphere”, Proceedings of the fourteenth international conference on Genetic and evolutionary computation conference companion (GECCO Companion '12), Terence Soule (Ed.). ACM, New York, NY, USA, 1379-1392. DOI=10.1145/2330784.2330946 http://doi.acm.org/10.1145/2330784.2330946
3. Cleland, CE. (2011). “Prediction and Explanation in Historical Natural Science”, Brit. J. Phil. Sci., 62: 551-582.
4. Longo, G., Montévil, M. (2012). “From physics to biology by extending criticality and symmetry breakings”, Prog. Biophys. Mol. Biol., 106(2): 340-347.