Stanley N. Salthe

THE ALLOMETRY OF REPRODUCTION: AN EMPIRICAL VIEW IN SALAMANDERS

In order to distinguish important variations in some life history traits, body size must be subtracted by constructing allometric null hypotheses. We present interspecific empirical models that describe the relationship among salamanders between body size and three variables: clutch volume, clutch size, and egg size. The relationship between log clutch volume and log body volume for 74 species of salamanders has a correlation of .899 and a slope of 0.64. The significance of this interspecific slope and lack of identity between it and intraspecific slopes is discussed. The relationships between log clutch size versus log body volume and log egg volume versus log body volume are largely determined by the mode of reproduction of the species. Data for four populations of salamanders of the genus Ambystoma are presented and compared with the models. The usefulness and necessity of first determining how a particular reproductive trait is expected to change with body size is made clear, for example, by observing that individuals of two of the populations studied have the same percent of their body volumes occupied by ova. In comparing the two populations with the empirical model, however, individuals are shown to contain very different clutch masses relative to what is expected for salamanders of their respective sizes. Constraints of size and shape must be considered in order to properly evaluate reproductive adaptations.

Evolution in thermodynamic perspective: An ecological approach

Recognition that biological systems are stabilized far from equilibrium by self-organizing, informed, autocatalytic cycles and structures that dissipate unusable energy and matter has led to recent attempts to reformulate evolutionary theory. We hold that such insights are consistent with the broad development of the Darwinian Tradition and with the concept of natural selection. Biological systems are selected that re not only more efficient than competitors but also enhance the integrity of the web of energetic relations in which they are embedded. But the expansion of the informational phase space, upon which selection acts, is also guaranteed by the properties of open informational-energetic systems. This provides a directionality and irreversibility to evolutionary processes that are not reflected in current theory.For this thermodynamically-based program to progress, we believe that biological information should not be treated in isolation from energy flows, and that the ecological perspective must be given descriptive and explanatory primacy. Levels of the ecological hierarchy are relational parts of ecological systems in which there are stable, informed patterns of energy flow and entropic dissipation. Isomorphies between developmental patterns and ecological succession are revealing because they suggest that much of the encoded metabolic information in biological systems is internalized ecological information. The geneological hierarchy, to the extent that its information content reflects internalized ecological information, can therefore be redescribed as an ecological hierarchy.This thermodynamic approach to evolution frees evolutionary theory from dependence on a crypto-Newtonian language more appropriate to closed equilibrial systems than to biological systems. It grounds biology non-reductively in physical law, and drives a conceptual wedge between functions of artifacts and functions of natural systems. This countenances legitimate use of teleology grounded in natural, teleomatic laws.

Physical foundations of evolutionary theory

Abstract The theory of evolution by natural selection is herein subsumed by the 2nd law of thermodynamics. The mathematical form of evolutionary theory is based on a re-examination of the probability concept that underlies statistical physics. Probability regarded as physical must include, in addition to isoenergic combinatorial configurations, also energy in conditional circumstances. Consequently, entropy as an additive logarithmic probability measure is found to be a function of the free energy, and the process toward the maximum entropy state is found equivalent to evolution toward the free energy minimum in accordance with the basic maxim of chemical thermodynamics. The principle of increasing entropy when given as an equation of motion reveals that expansion, proliferation, differentiation, diversification, and catalysis are all ways for a system to evolve toward the stationary state in its respective surroundings. Intriguingly, the equation of evolution cannot be solved when there remain degrees of freedom to consume the free energy, and hence evolutionary trajectories of a non-Hamiltonian system remain intractable. Finally, when to-and-from flows of energy are balanced between a system and its surroundings, the system is at the Lyapunov-stable stationary state. The principle of maximal energy dispersal, equivalent to the maximal rate of entropy production, gives rise to the ubiquitous characteristics, conventions, and regularities found in nature, where thermodynamics makes no demarcation line between animate and inanimate.

The Spontaneous Origin of New Levels in a Scalar Hierarchy

Given a background of universal thermodynamic disequilibrium, I suggest that the interpolation of new levels in a material scale hierarchy is favored when the entropy production of a local region would be increased by such structural complexification. This would involve the separation by order of magnitude of the average dynamical rate of the new level compared to those of the resulting contiguous levels from which it became disentangled, thereby facilitating laminar flows. Here the Second Law of thermodynamics is understood as a final cause, which can be expressed in this creative way when the surrounding superstructure has a form allowing it to mediate this change (by, e.g., focusing kinetics, etc.), and given, as well, sufficiently differentiated local energy gradients to materially support the increased local dissipation.

Economies evolve by energy dispersal

Abstract: Economic activity can be regarded as an evolutionary process governed by the 2 nd law of thermodynamics. The universal law, when formulated locally as an equation of motion, reveals that a growing economy develops functional machinery and organizes hierarchically in such a way as to tend to equalize energy density differences within the economy and in respect to the surroundings it is open to. Diverse economic activities result in flows of energy that will preferentially channel along the most steeply descending paths, leveling a non-Euclidean free energy landscape. This principle of ‗maximal energy dispersal‘, equivalent to the maximal rate of entropy production, gives rise to economic laws and regularities. The law of diminishing returns follows from the diminishing free energy while the relation between supply and demand displays a quest for a balance among interdependent energy densities. Economic evolution is dissipative motion where the driving forces and energy flows are inseparable from each other. When there are multiple degrees of freedom, economic growth and decline are inherently impossible to forecast in detail. Namely, trajectories of an evolving economy are non-integrable,

Global idealism/local materialism

We are concerned with two modes of describing the dynamics of natural systems. Global descriptions require simultaneous global coordination of all dynamical operations. Global dynamics, including mechanics, remain invariant in the absence of external perturbation. But, failing impossible global coordination, dynamical operations could actually become coordinated only locally. In local records, as in global ones, the law of the excluded middle would be strictly observed, but without global coordination it could only be fullfilled sequentially by passing causative factors forward onto subsequent contiguous operations.The local dynamics of sequential operations would be indefinite with regard to how commitments will be made which will avoid violating the law of the excluded middle, but any resulting record will be as definite as if there had been global coordination. While maintaining an agential capacity for making contingent choices internally, local dynamics could be cumulated into a global record of seemingly simultaneous operations. Natural selection within a framework of local dynamics would have a capacity for making opportunistic commitments, but its effects in a posterior record can be reduced to the mechanistic neodarwinian version as if there had been a global dynamics. However, the resulting global description falsifies the actual material nature of the dynamics.

Geographic variation of the lactate dehydrogenases ofRana pipiens andRana palustris

Electrophoretic, immunological, catalytic, and enzyme recombination studies were carried out on the HLDHs, and to a lesser extent on the MLDHs, of many populations of Rana pipiensand R. palustris.HLDH is far more variable from one population to the next than is MLDH, which appears to be identical in both species as far as can be determined by the methods employed. Of all the methods used, electrophoresis is capable of distinguishing the most differences between populations. However, two electrophoretically identical groups of enzymes can be differentiated immunologically. The geographic distribution of HLDH variability is generally concordant with the distributions of different mating calls, with the results of hybridization studies, and also with the old subspecies distributions. Eleven different forms of HLDH have been discovered so far in the R. pipienscomplex.

TWO FORMS OF HIERARCHY THEORY IN WESTERN DISCOURSES

In the twentieth century two different forms of hierarchy theory have been frequently conflated. One, the scalar hierarchy, is used in systems science and ecology. It describes constraint relations on dynamics between systems of different scale. It is useful in describing parts and wholes, and processes taking place in such complex structures. The other, the specification hierarchy, is an older discourse dating back to Plato, and, as a theory of development, to Aristotle. In the twentieth century it was relegated to peripheral importance in biology, but has continued to inform social science and psychology. It can be represented as a system of nested classes, the outermost class containing the most general phenomena, the innermost the most highly specified. These integrative levels can be considered as stages of development as well. Each new stage transcends the one before it and integrates it into a new whole. Incredibly, the same statements can be made about a system from these two viewpoints, even thou...

Self-organization in hierarchical systems

Abstract Currently there are two movements emerging within systems theory in connection with biology: self-organization and hierarchy theory. They are treated together here because they represent polar oppositional perspectives. Self-organization is concerned with change viewed as from within a changing system; whereas hierarchy theory, in the form familiar to most systems workers, is an externalist descriptive framework for dealing with constraints bearing on a system from multiple scalar levels. Hierarchy theory also deals externally, in another form (the specification hierarchy), with integrative levels as developmental stages within an ontogenetic trajectory. In this article we conclude that, although self-organization and hierarchies are incommensurable discourses, they could be taken to be complementary, each supplying what the other lacks in understanding systems.

Ecological boundaries in the context of hierarchy theory.

Ecological boundaries have been described as being multiscalar or hierarchical entities. However, the concept of the ecological boundary has not been explicitly examined in the context of hierarchy theory. We explore how ecological boundaries might be envisioned as constituents of scalar hierarchical systems. Boundaries may be represented by the surfaces of constituents or as constituents themselves. Where surfaces would correspond to abrupt transition zones, boundary systems might be quite varied depending on hierarchical context. We conclude that hierarchy theory is compatible with a functional vision of ecological boundaries where functions can be largely represented as the processing or filtering of ecological signals. Furthermore, we postulate that emergent ecological boundaries that arise on a new hierarchical level may contribute to the overconnectedness of mature ecosystems. Nevertheless, a thermodynamic approach to the emergence and development of boundary systems does indicate that in many situations, ecological boundaries would persist in time by contributing to the energy production of higher hierarchical levels.