https://www.selleckchem.com/products/MGCD0103(Mocetinostat).html All organisms have a stress response system to cope with environmental threats, yet its precise form varies hugely within and across individuals, populations, and species. While the physiological mechanisms are increasingly understood, how stress responses have evolved remains elusive. Here, we show that important insights can be gained from models that incorporate physiological mechanisms within an evolutionary optimality analysis (the 'evo-mecho' approach). Our approach reveals environmental predictability and physiological constraints as key factors shaping stress response evolution, generating testable predictions about variation across species and contexts. We call for an integrated research programme combining theory, experimental evolution, and comparative analysis to advance scientific understanding of how this core physiological system has evolved.The global coronavirus disease 2019 (COVID-19) will exacerbate the negative health outcomes associated with the concurrent opioid overdose crisis in North America. COVID-19 brings unique challenges for practitioners who provide opioid use disorder (OUD) care. The majority of overdose deaths in the Canadian province of British Columbia occur in housing environments. Some supportive housing environments in Vancouver, British Columbia, have on-site primary care and substance use disorder treatment clinics. Some of these housing environments also include supervised consumption services. These housing environments needed to make adjustments to their care to adhere to COVID-19 physical distancing measures. Such adjustments included a pandemic withdrawal management program to provide patients with a pharmaceutical grade alternative to the toxic illicit drug supply, which allow patients to avoid the heightened overdose risk while using illicit drugs alone or potentially exposing themselves to COVID-19 while using drugs in a group setting. Other modifications