Organisms must strike a delicate balance between robustness, which preserves advantageous traits, and plasticity, which allows adaptation to changing environments. This balance is crucial for survival and evolution, yet our understanding of how these forces interact across multiple traits during adaptation remains incomplete. Most studies have focused on the plasticity of individual traits, overlooking the broader patterns of co-evolution under new environmental pressures. To address this gap, my research centers on analyzing the patterns of correlational selection using genomic data and morphological measurements in experimentally evolved populations of Drosophila melanogaster.

To explore these dynamics, I reared populations of D. melanogaster under control and dietary stress conditions for 30 generations. This study examines how robustness and plasticity emerge and interact at various levels — developmental, functional (flight performance), and morphological (wing shape and size) — to shape the organism’s adaptability in stressful environments. A key component of this study is the assessment of fluctuating asymmetry (FA), which refers to random differences between the left and right sides of bilaterally symmetrical traits. Since these differences occur despite both sides developing from the same genetic code, FA serves as a metric of developmental noise and a sensitive indicator of an organism’s ability to maintain phenotypic integrity under stress. By integrating FA with analyses of wing morphology and flight performance, this project offers a novel approach to understanding how traits co-evolve in response to environmental challenges.

My initial findings indicate that exposure to dietary stress leads to an increase in fluctuating asymmetry in flies, suggesting a deficiency in maintaining developmental stability. However, this instability also aligns with an adaptive strategy, as the evolved populations exhibit increased variability in wing morphology, suggesting that developmental instability may serve as a mechanism for exploring broader phenotypic space in a new environment.

The interdisciplinary nature of this study, bridging ecological, genetic, and biomechanical perspectives, provides novel insights into stress resilience across different phenotypic levels. At KLI, I will focus on integrating multivariate quantitative genetics with genomic data to explore the dynamic shifts in trait correlations during adaptation. This approach will not only deepen our understanding of how traits co-evolve but also shed light on the speed and nature of morphological evolution. The findings from this research have broad implications for evolutionary biology, offering new perspectives on how organisms balance stability and flexibility to thrive in changing environments. By elucidating these mechanisms, this study will contribute to a more comprehensive understanding of the adaptive strategies that organisms employ in response to environmental stressors.