Emily Green, ENV / ITEHP PhD candidate will present this talk. Animals have evolved in environments abundant with microorganisms, resulting in deeply integrated host-microbe interactions that profoundly shape development, physiology, and survival. However, our understanding of these interactions is largely derived from post-embryonic, free-living life stages, when organisms are in direct contact with microbes. Whether environmental microbial communities influence embryogenesis, particularly in oviparous organisms where embryos are encased in a protective chorion, remains poorly understood. Moreover, because embryogenesis represents a highly sensitive developmental window during which environmental perturbations, including chemical pollutants, can alter developmental outcomes, it remains unclear whether microbial-driven modulation of early development contributes to long-term environmental resilience or adaptation. By addressing these questions across multiple biological scales, from molecular signaling and physiological function, to population-level responses, Emily's research demonstrates that host-microbe interactions play a critical role during early vertebrate development by shaping developmental, metabolic, and xenobiotic response pathways that enhance resilience to chemical stress. Emily's results further reveal that these effects contribute to population-level adaptation, providing a mechanistic framework for understanding how host-microbiome interactions shape ecological fitness and evolutionary trajectories of vertebrates living in microbially dynamic natural habitats.