Telomere attrition and growth: a life-history framework and case study in common terns

The relationship between growth and age-specific telomere length, as a proxy of somatic state, is increasingly investigated, but observed patterns vary and a predictive framework is lacking. We outline expectations based on the assumption that telomere maintenance is costly and argue that individual heterogeneity in resource acquisition is predicted to lead to positive covariance between growth and telomere length. However, canalization of resource allocation to the trait with a larger effect on fitness, rendering that trait relatively invariant, can cause the absence of covariance. In a case study of common tern (Sterna hirundo) chicks, in which hatching order is the main determinant of variation in resource acquisition within broods, we find that body mass, but not telomere length or attrition, varies with hatching order. Moreover, body mass and growth positively predict survival to fledging, whereas telomere length and attrition do not. Using a novel statistical method to quantify st...生长与作为躯体状态（somatic state）替代指标的年龄特异性端粒长度（telomere length）之间的关联正日益受到学界关注，但已观测到的模式存在差异，且尚未形成成熟的预测框架。我们基于端粒维持存在代谢成本这一核心假设梳理了相关理论预期，并提出：个体在资源获取能力上的异质性会引发生长与端粒长度之间的正协变关系。然而，若对资源分配进行渠化调控，将资源偏向分配至对适合度影响更显著的性状，使该性状保持相对恒定，则可能导致二者无协变关系。在以普通燕鸥（Sterna hirundo）雏鸟为研究对象的案例中，雏鸟窝内资源获取差异的核心决定因素为孵化顺序，我们发现雏鸟体质量随孵化顺序发生显著变化，但端粒长度与端粒损耗并未呈现此类差异。此外，体质量及其生长速率可正向预测雏鸟出飞前的存活率，而端粒长度与端粒损耗则无此类预测能力。我们采用一种新型统计方法以量化st...