An entropic model of Gaia

Does Gaia Play Dice? Simple Models of Non-Darwinian Selection

In this article, we introduce some simple models, based on rolling dice, to explore mechanisms proposed to explain planetary habitability. The idea is to study these selection mechanisms in an analytically tractable setting, isolating their consequences from other details which can confound or obscure their effect in more realistic models. We find that the observable of interest, the face value shown on the die, "improves" over time in all models. For two of the more popular ideas, Selection by Survival and Sequential Selection, this is down to sampling effects. A modified version of Sequential Selection, Sequential Selection with Memory, implies a statistical tendency for systems to improve over time. We discuss the implications of this and its relationship to the ideas of the "Inhabitance Paradox" and the "Gaian bottleneck."

Selection principles for Gaia

The Gaia hypothesis considers the life-environment coupled system as a single entity that acts to regulate and maintain habitable conditions on Earth. In this paper we discuss three mechanisms which could potentially lead to Gaia: Selection by Survival, Sequential Selection and Entropic Hierarchy. We use the Tangled Nature Model of co-evolution as a common framework for investigating all three, using an extended version of the standard model to elaborate on Gaia as an example of an entropic hierarchy. This idea, which combines sequential selection together with a reservoir of diversity that acts as a 'memory', implies a tendency towards growth and increasing resilience of the Gaian system over time. We then discuss how Gaian memory could be realised in practice via the microbial seed bank, climate refugia and lateral gene transfer and conclude by discussing testable implications of an entropic hierarchy for the study of Earth history and the search for life in the universe. This paper adds to the existing taxonomy of Gaia hypotheses to suggest an "Entropic Gaia" where we argue that increasing biomass, complexity and enhanced habitability over time is a statistically likely feature of a co-evolving system.

Asynchronous time-space model for evolutionary market

An economic system is thought to be evolutionary growing. Economists investigate human decision-making by monetary value. However, the emergent property of the economy has not been explained. A model considering the extent of the monetary value is required. In this paper, a time-space model is proposed to elucidate the economic evolution of a market. Since the market activities are always open and realtime, the model of time and space is complicated. For the complexity, the probabilistic boundary and expectations under a low-possibility are introduced. Then, time and space cannot be separated and are defined as an asynchronous relationship. We apply this time-space model to the adaptive agent models of single and double auctions. The results of the numerical simulation indicate the intermittency in a broad area of the control parameter. This result concludes that the extent of monetary value can be a basis of the evolutionary market.