解释个体适应度的变化是进化生物学的关键目标。最近,端粒,重复DNA序列覆盖染色体末端,作为身体状态的生物标志物获得了关注,生理成本,和衰老。现有的研究为端粒长度是否与健康相关提供了混合证据,包括生存和生殖输出。此外,很少有研究研究端粒长度的变化率与野生种群的适应性之间的关系。这里,我们密切监测了一群孤立的麻雀,并收集纵向端粒和生活史数据(16年,1225个人)。我们测试了端粒长度及其变化率是否可以预测适应度,即生存,寿命和年度和终身生殖努力和成功。端粒长度正预测短期生存率,独立于年龄,但没有预测寿命,提示端粒长度-生存与年龄或其他外在死亡因素的相关性下降。端粒长度与存活的正相关转化为生殖益处,随着端粒较长的鸟类产生更多的遗传新兵,在他们的一生中孵化和饲养更多的雏鸟。相比之下,端粒动力学和年生殖产量之间没有关联,表明端粒动力学可能无法反映该人群的繁殖成本,可能被个人质量的变化所掩盖。端粒长度的变化率与寿命和终生生殖成功都不相关。我们的结果提供了进一步的证据,表明端粒长度与适应性相关,并有助于我们对选择的理解,和进化,端粒动力学。
Explaining variation in individual fitness is a key goal in evolutionary biology. Recently, telomeres, repeating DNA sequences capping chromosome ends, have gained attention as a biomarker for body state, physiological costs, and senescence. Existing research has provided mixed evidence for whether telomere length correlates with fitness, including survival and reproductive output. Moreover, few studies have examined how the rate of change in telomere length correlates with fitness in wild populations. Here, we intensively monitored an insular population of house sparrows, and collected longitudinal telomere and life history data (16 years, 1225 individuals). We tested whether telomere length and its rate of change predict fitness measures, namely survival, lifespan and annual and lifetime reproductive effort and success. Telomere length positively predicted short-term survival, independent of age, but did not predict lifespan, suggesting either a diminishing telomere length-survival correlation with age or other extrinsic factors of mortality. The positive association of telomere length with survival translated into reproductive benefits, as birds with longer telomeres produced more genetic recruits, hatchlings and reared more fledglings over their lifetime. In contrast, there was no association between telomere dynamics and annual reproductive output, suggesting telomere dynamics might not reflect the costs of reproduction in this population, potentially masked by variation in individual quality. The rate of change of telomere length did not correlate with neither lifespan nor lifetime reproductive success. Our results provide further evidence that telomere length correlates with fitness, and contribute to our understanding of the selection on, and evolution of, telomere dynamics.