Developmental stress and telomere dynamics in a genetically polymorphic species

A central objective of evolutionary biology is understanding variation in life-history trajectories and aging rate, or senescence. Senescence can be affected by tradeoffs and behavioral strategies in adults, but may also be affected by developmental stress. Developmental stress can accelerate telomere degradation, with long-term longevity and fitness consequences. Little is known regarding whether variation in developmental stress and telomere dynamics contribute to patterns of senescence during adulthood. We investigated this question in the dimorphic white-throated sparrow (Zonotrichia albicollis), a species in which adults of the two morphs exhibit established differences in behavioral strategy and patterns of senescence, and also evaluated the relationship between oxidative stress and telomere length. Tan morph females, which exhibit high levels of unassisted parental care, display faster reproductive senescence than white females, and faster actuarial senescence than all of th...进化生物学的核心目标之一，是阐明生活史轨迹与衰老速率（senescence）的变异模式。衰老既会受到成体阶段的生活史权衡与行为策略的影响，也可能受发育应激的调控。发育应激可加速端粒（telomere）降解，并对个体的长期寿命与适合度产生后续影响。目前学界对发育应激与端粒动态（telomere dynamics）的变异是否会影响成体阶段的衰老模式这一问题仍知之甚少。本研究以二态性的白喉带鹀（Zonotrichia albicollis）为研究对象，该物种的两种形态成体在行为策略与衰老模式上存在已被证实的差异；同时本研究还探讨了氧化应激（oxidative stress）与端粒长度之间的关联。表现出高水平无协助亲代抚育行为的棕褐色形态雌鸟，其生殖衰老速率快于白色形态雌鸟，且种群统计衰老速率快于所有……