Evolution Under Pressure: Navigating Adaptation from Deep Time to the Anthropocene

Environmental stress has always represented one of the most powerful evolutionary forces determining biological diversity. Organisms have evolved a remarkable variety of structural, physiological, biochemical, and behavioral strategies that enable survival under adverse and fluctuating environmental conditions [1]. However, contemporary global change has accelerated the intensity, frequency, and complexity of environmental perturbations, generating unprecedented selective pressures on living systems worldwide [2]. Anthropogenic climate change, urbanization, habitat fragmentation, salinization, altered nutrient cycles, wildfire intensification, pollution, and anthropogenic acoustic emissions are increasingly transforming ecological systems at local and global scales. In this rapidly changing scenario, understanding how organisms perceive, tolerate, and adapt to environmental stress has become one of the central challenges of modern biology [3]. Importantly, environmental adaptation rarely occurs in response to a single stress factor. Natural systems are increasingly characterized by multifactorial stress conditions in which biological responses emerge through complex interactions among molecular regulation, physiological plasticity, ecological dynamics, and evolutionary processes. Consequently, modern environmental stress biology is progressively moving beyond single-factor analyses toward integrative and multidisciplinary approaches capable of connecting mechanisms across biological scales. The Special Issue (SI) entitled “Adaptation of Living Species to Environmental Stress” was conceived to provide a multidisciplinary platform for investigating these complex responses across molecular, organismal, ecological, and evolutionary levels. The contributions collected in this volume reflect the breadth of this field and demonstrate the remarkable diversity of adaptive strategies across taxa and ecosystems.