Information Across the Ecological Hierarchy

Ulanowicz Ulanowicz

doi:10.3390/e21100949

Abstract

The ecosystem is a theatre upon which is presented, in various degrees and at differing scales, a drama of constraint and information vs. disorganization and entropy. Concerning biology, most think immediately of genomic information. It strongly constrains the form and behavior of individual species, but its influence upon community structure is indeterminate. At the community level, information acts as a formal cause behind regular patterns of development. Community structure is an amalgam of information and entropy, and the Gibbs–Boltzmann formula departs from the thermodynamic sense of entropy. It measures only the extreme that entropy might reach if the elements of the system were completely independent. A closer analogy to physical entropy in systems with interactions is the conditional entropy—the amount by which the Shannon measure is reduced after the information in the constraints among elements has been subtracted. Finally, at the whole ecosystem level, in communities that inhabit mostly fixed physical environments (e.g., landscapes or seabeds), the distributions of plants and animals appear to be independent both of causal mechanisms and trophic controls, and assume instead forms that maximize the overall entropy of dispersal.

Highlights

The ecosystem is a theatre upon which is presented, in various degrees and at differing scales, a drama of constraint and information vs. disorganization and entropy
This ambition pertains to the level of synecology, which at first glance may seem to have little to do with information
Does H in (3) relate to actual physical entropy? Original phenomenological thermodynamics distinguished between the total energy possessed by a system and the fraction thereof that can be converted into work

Summary

Genomic Information Acts Primarily on Organisms

Information plays different roles in ecology at various scales, and the goal here is to characterize and compare those disparate actions. For example, the words of renowned developmental biologist, Gunter Stent: Consider the establishment of ecological communities upon colonization of islands or the growth of secondary forests. Both of these examples are regular phenomena in the sense that a more or less predictable ecological structure arises via a stereotypic pattern of intermediate steps, in which the relative abundances of various types of flora and fauna follow a well-defined sequence. The regularity of these phenomena is obviously not the consequence of an ecological program encoded in the genomes of the participating taxa [1]. Entropy 2019, 21, 949 pursuant to such changes cannot even be formulated in advance [3,4], so that, effectively, the role of genomes appears to be limited to recording the success or failure of their particular phenotypes and their associated behaviors

System Level Information

The Relationship Between Shannon Diversity and True Entropy

Maximal Entropy in Mature Environments

Conclusions