Am Nat. 2023 Jun;201(6):E140-E152. doi: 10.1086/724384. Epub 2023 Apr 4.
AbstractThe basic tenets of the evolutionary theories of senescence are well supported. However, there has been little progress in determining the relative influences of mutation accumulation and life history optimization. The causes of the well-established inverse relationship between life span and body size across dog breeds are used here to test these two classes of theories. The life span-body size relationship is confirmed for the first time after controlling for breed phylogeny. The life span-body size relationship cannot be explained by evolutionary responses to differences in extrinsic mortality either of contemporary breeds or of breeds at their establishment. The development of breeds larger and smaller than ancestral gray wolves has occurred through changes in early growth rate. This may explain the increase in the minimum age-dependent mortality rate with breed body size and thus higher age-dependent mortality throughout adult life. The main cause of this mortality is cancer. These patterns are consistent with the optimization of life history as described by the disposable soma theory of the evolution of aging. The dog breed life span-body size relationship may be the result of the evolution of greater defense against cancer lagging behind the rapid increase in body size during recent breed establishment.
摘要衰老的进化理论的基本原理得到了很好的支持。然而，在确定突变积累和生命史优化的相对影响方面进展甚微。本文利用犬种之间寿命与体型之间已确立的反比关系来检验这两类理论。在控制了品种系统发育后，首次证实了寿命-体型关系。寿命-体型关系不能用对当代品种或品种建立时的外在死亡率差异的进化反应来解释。比灰狼祖先更大或更小的品种的发展是通过早期生长速度的变化而发生的。这可以解释随着品种体型的增加，年龄相关死亡率的最低依赖性增加，从而导致整个成年生命的年龄相关死亡率增加。这种死亡率的主要原因是癌症。这些模式与衰老进化的可抛弃体理论所描述的生命史优化是一致的。犬种的寿命-体型关系可能是由于在最近的品种建立过程中，身体大小快速增加，而对癌症的防御能力却落后，从而导致的进化结果。
