第七十五期：活的灿烂，死得干脆 - 鸟类：我们至死是少年！

我们人类的衰老过程就是一直在走下坡路，30岁以后体能就逐渐下滑。但鸟类，尤其是海鸟的生命轨迹就像个矩形。他们的巅峰状态能保持几十年，最后再“断崖式”地退场。比如中途岛的信天翁“智慧”，75岁仍活跃在求偶一线，新伴侣、新鸟蛋一样不落。它们的肌肉和线粒体到老都不缩水，飞行引擎终身高效！
​如果按“生命速率理论”，代谢越快寿命就越短。这个规则在哺乳动物中适用，可是鸟类的出现就是来打破规则的：它们体温41℃、血糖超高，可是他们活得比实验室里谨慎养生的老鼠更久。这是因为鸟类的细胞“发电机”燃烧充分，自由基泄漏极少，可以避免氧化损伤。他们的细胞膜也和哺乳动物不同，富含稳定脂肪酸，就像给零件刷了防锈漆，把不太防火的木材换成了防火砖，抗老化能力MAX！​
而且他们的肌肉不会随着年龄而萎缩。信天翁如果胸肌流失10%，就能直接告别跨洋飞行，准备开席了。可是鸟类能终身维持肌肉结构和功能，20多岁的老鸟还是会肌肉紧绷和2岁小青年差不多。
还有研究发现，切除睾丸的雄性动物（比如阉鸡、动物园的哺乳动物）会活得更久。在鸟类中，雄性（ZZ染色体）普遍比雌性长寿，因双套染色体备份基因更稳！​
飞行让可以鸟类轻松躲避天敌，死亡率大幅降低。既然可能活很久，自然选择就倾向投资“身体维修基因”。相反，老鼠活在危险中，策略就只能是“赶紧生，修什么修”！
跳求偶舞的黑背信天翁“智慧”（Wisdom - 右）
66岁的“智慧”在孵蛋
70岁的“智慧”成功孵出宝宝
欢迎您加入到我们的听友群 V：hotpeaker
参考文献：
* Seasonal patterns of neurogenesis in European starlings (Sturnus vulgaris) are region- and sex-specific | DOI: 10.1111/jne.13455
* Goldman, S. A., & Nottebohm, F. (1983). "Neuronal production, migration, and differentiation in a vocal control nucleus of the adult female canary brain." Proceedings of the National Academy of Sciences, 80(8), 2390-2394.
* Nottebohm, F. (1981). "A brain for all seasons: cyclical anatomical changes in song control nuclei of the canary brain." Science, 214(4527), 1368-1370.
* Kirn, J. R., & Nottebohm, F. (1993). "Direct evidence for loss and replacement of projection neurons in adult canary brain." Journal of Neuroscience, 13(4), 1654-1663.
* Barnea, A., & Nottebohm, F. (1994). "Seasonal recruitment of hippocampal neurons in adult free-ranging black-capped chickadees." Proceedings of the National Academy of Sciences, 91(23), 11217-11221.
* The retrograde response: a compensatory mechanism to alleviate aging during caloric restriction? | Experimental Gerontology 2004
* Comparative biology of aging in birds: an updateSterilization and contraception increase lifespan across vertebrates | Nature 2025 | DOI: 10.1038/s41586-025-09836-9
* Sexual selection drives sex difference in adult life expectancy across mammals and birds | Science Advances | DOI: 10.1038/s41586-025-09836-9
* Avian senescence: underlying mechanisms | Journal of Ornithology | DOI: 10.1007/s10336-007-0186-5
* Avian longevities and their interpretation under evolutionary theories of senescence | Journal of Zoology 280(2010) 103–155”
* Avian Lifespan Network Reveals Shared Mechanisms and New Key Players in Animal Longevity | DOI: 10.1111/acel.70156
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片头：Forever Yong - John De Sohn & LIAMOO
片尾：纵贯线 - 亡命之徒