Fitness landscapes and evolution

TL;DR

This paper explores fitness landscapes, the Fundamental Theorem of Natural Selection, and various models of evolution, emphasizing the importance of flat landscapes and multi-level selection in understanding evolutionary processes.

Contribution

It provides a derivation of the Fundamental Theorem, reviews the quasispecies model, and discusses the significance of flat fitness landscapes and multi-level selection in evolution.

Findings

Average fitness increases with nonzero variance

Flat fitness landscapes are relevant to molecular evolution

Two-level selection concepts are important in evolutionary theory

Abstract

The concept of fitness is introduced, and a simple derivation of the Fundamental Theorem of Natural Selection (which states that the average fitness of a population increases if its variance is nonzero) is given. After a short discussion of the adaptative walk model, a short review is given of the quasispecies approach to molecular evolution and to the error threshold. The relevance of flat fitness landscapes to molecular evolution is stressed. Finally a few examples which involve wider concepts of fitness, and in particular two-level selection, are shortly reviewed.