The evolution of growth trajectories and other complex quantitative characters

Area of Science:

• Evolutionary biology
• Developmental biology
• Quantitative genetics

Background:

• Growth trajectories are continuous functions, unlike discrete measurements.
• Understanding evolutionary potential requires analyzing genetic variation and developmental constraints.

Purpose of the Study:

• To review methods for predicting growth trajectory evolution under selection.
• To quantify evolutionary constraints on growth trajectories imposed by developmental processes.

Main Methods:

• Analysis of genetic data from mice.
• Application of recently developed methods for predicting evolutionary trajectories.
• Quantification of genetic variation patterns and developmental constraints.

Main Results:

• Developmental processes impose constraints on growth trajectory evolution.
• These constraints define achievable and unachievable growth trajectory families.
• Few evolutionary degrees of freedom exist for growth trajectories, despite ample additive genetic variation.

Conclusions:

• Constraints on growth trajectories can be quantified, offering insights into evolutionary options.
• Findings are applicable to understanding natural population evolution and improving domesticated species.
• Methods generalize to other complex traits like morphology and norms of reaction.