Multidimensional analysis of Drosophila wing variation in Evolution Canyon

Area of Science:

• Evolutionary biology
• Developmental biology
• Ecology

Background:

• Environmental stress is a key evolutionary driver, influencing selection and organismal evolvability.
• Temperature is a critical ecological factor with significant experimental tractability.
• Evolution Canyon presents a natural laboratory for studying evolutionary differentiation due to ecological parameters.

Purpose of the Study:

• To investigate the effect of developmental temperature on phenotypic variation in Drosophila melanogaster wings.
• To assess evolutionary differentiation between populations from different slopes of Evolution Canyon.
• To analyze phenotypic plasticity, genetic variation, and fluctuating asymmetry in response to environmental conditions and temperature.

Main Methods:

• Utilized Drosophila melanogaster isofemale lines from Evolution Canyon.
• Combined geometric and traditional morphometrics to analyze wing shape and size.
• Investigated phenotypic plasticity, genetic variation, individual variation, and fluctuating asymmetry.
• Employed metric multi-dimensional scaling to compare patterns of variation.

Main Results:

• Developmental temperature significantly influenced wing mean size and shape.
• Limited evidence for evolutionary differentiation between canyon slopes was found.
• Environmental conditions on the south-facing slope did not consistently affect phenotypic variation.
• Wing variability was not consistently affected by temperature.
• Patterns of individual variation and fluctuating asymmetry suggest distinct underlying developmental processes.

Conclusions:

• Developmental temperature is a primary factor structuring wing morphology in Drosophila melanogaster.
• Ecological differentiation between slopes is less pronounced than the effect of experimental temperature.
• Individual variation and fluctuating asymmetry may arise from partially independent developmental pathways.