Evolutionary and Ecological Processes Determining the Properties of the Matrix

Area of Science:

• Evolutionary Biology
• Quantitative Genetics
• Population Genetics

Background:

• The additive genetic variance-covariance (G) matrix describes the genetic basis of phenotypic evolution.
• Understanding the forces shaping the G matrix is crucial for predicting adaptive change.

Purpose of the Study:

• To decompose the G matrix into contributions from selection, genetic drift, mutation, and environmental fluctuations.
• To assess the sufficiency of existing evolutionary theorems under environmental deterioration.

Main Methods:

• Applied classical theory of selection, drift, and mutation balance.
• Approximated fitness as a linear function of phenotypes with environmental fluctuations.
• Decomposed the G matrix into four additive components.

Main Results:

• The G matrix can be decomposed into selection, drift, mutation, and environmental fluctuation components.
• Selection is counteracted by environmental deterioration, leading to significant phenotypic changes.
• Fisher's fundamental theorem and Lande's gradient formula require correction for environmental deterioration.

Conclusions:

• Existing evolutionary theorems are insufficient without accounting for environmental deterioration.
• The theory provides a framework for comparative studies on environmental effects.
• Eigenvector analysis of the G matrix can reveal relative contributions of phenotypes to fitness.