T C Fogarty | PubMed Health

PubMed2000

Information characteristics and the structure of landscapes.

Various techniques for statistical analysis of the structure of fitness landscapes have been proposed. An important feature of these techniques is that they study the ruggedness of landscapes by measuring their correlation characteristics. This paper proposes a new information analysis of fitness landscapes. The underlying idea is to consider a fitness landscape as an ensemble of objects that are related to the fitness of neighboring points. Three information characteristics of the ensemble are defined and studied. They are termed: information content, partial information content, and information stability. The information characteristics of a range of landscapes with known correlation features are analyzed in an attempt to reveal the advantages of the information analysis. We show that the proposed analysis is an appropriate tool for investigating the structure of fitness landscapes.

Biological Evolution↗

PubMed1995

Artificial symbiogenesis.

Symbiosis is the phenomenon in which organisms of different species live together in close association, resulting in a raised level of fitness for one or more of the organisms. Symbiogenesis is the name given to the process by which symbiotic partners combine and unify-forming endosymbioses and then potentially transferring genetic material-giving rise to new morphologies and physiologies evolutionarily more advanced than their constitutents. In this article we begin by using the NKC model of coevolution to examine endosymbiosis and its effect on the evolutionary performance of the partners involved. We are then able to suggest the conditions under which endosymbioses are more likely to occur and why; we find they emerge between organisms within a window of their respective "chaotic gas regimes" and hence that the association represents a more stable state for the partners. The conditions under which gene transfer is more likely to represent an advantage for such endosymbionts are then examined within the same model. We find that, providing a suitable pathway exists, such a process can lead to a more efficient genetic configuration for the symbionts within a window that overlaps that in which endosymbioses occur. Finally, the results are used as grounds for implementing symbiogenesis within artificial evolutionary multiagent systems.

Algorithms↗