The evolution of lifespan and ageing in response to dietary macronutrients in male and female decorated crickets

Dietary macronutrients regulate lifespan and ageing, yet little is known about their evolutionary effects. Here, we examine the evolutionary response of these traits in decorated crickets (Gryllodes sigillatus) maintained on diets varying in caloric content and protein-to-carbohydrate ratio. After 37 generations, each population was split: half remained on the evolution diet and half switched to a standardized diet. Crickets lived longer and aged slower when evolving on high-calorie (both sexes) and carbohydrate-biased (females only) diets and had lower baseline mortality on high-calorie (females only) diets. However, on the standardized diet, crickets lived longer when evolving on high-calorie diets (both sexes), aged slower on high-calorie (females only) and carbohydrate-biased (both sexes) diets, and had lower baseline mortality on high-calorie (males only) and protein-biased (both sexes) diets. Lifespan was longer and baseline mortality lower when provided the evolution versus the s..., , , # The evolution of lifespan and ageing in response to dietary macronutrients in male and female decorated crickets

We quantified median LS and ageing parameters for adult crickets of each sex for each population (36 populations in total, including populations evolving on their respective diets and those switched to the SCD \"ancestral\" diet). To determine the most appropriate ageing model and estimate ageing and baseline mortality rates for our data we used the “BaSTA” package in R (version 4.0.0, R Core Team) to fit the Gompertz, Weibull, and Logistic models of ageing within a Bayesian framework across our diet populations and the sexes (Colchero et al., 2012). For each sex per diet population, we performed three BaSTA simulations (one for each of the above ageing models), each with 2,200,200 iterations, a burn-in of 200,000 chains, and an MCMC chain sample taken every 4,000 iterations. Survival curves were obtained using the \"survival\" and \"survminer\" packages, using default settings....

膳食宏量营养素可调控寿命与衰老进程，但目前对其演化效应的认知仍较为匮乏。本研究以装饰蟋蟀（Gryllodes sigillatus）为研究对象，探究其上述性状在不同热量含量、蛋白质与碳水化合物比例的膳食条件下的演化响应。经过37代繁育后，将每个种群分为两组：一半继续维持原演化膳食饲养，另一半则转换至标准化膳食饲养。

在高热量（两性均如此）以及碳水化合物占比偏高（仅雌性）的膳食中演化的蟋蟀，其寿命更长、衰老速率更慢；且仅在高热量膳食中演化的雌性蟋蟀，其基础死亡率更低。但当以标准化膳食饲养时，曾在高热量膳食中演化的蟋蟀（两性均如此）寿命更长；曾在高热量（仅雌性）以及碳水化合物占比偏高（两性均如此）的膳食中演化的蟋蟀，衰老速率更慢；而曾在高热量（仅雄性）以及蛋白质占比偏高（两性均如此）的膳食中演化的蟋蟀，其基础死亡率更低。当以演化膳食而非[原文未完整呈现的膳食类型]饲养时，蟋蟀的寿命更长、基础死亡率更低。

# 雌雄装饰蟋蟀在膳食宏量营养素作用下的寿命与衰老演化

本研究针对每个种群的不同性别成年蟋蟀，量化了其中位寿命（Lifespan, LS）与衰老相关参数（本次共涉及36个种群，涵盖在各自演化膳食中繁育的种群，以及转换至SCD「祖先式」膳食（Standardized Diet, SCD）的种群）。为筛选最适配的衰老模型并估算本研究数据中的衰老速率与基础死亡率，我们使用R语言（版本4.0.0，R核心团队）中的"BaSTA"工具包，针对不同膳食种群与性别，在贝叶斯框架下拟合了戈姆佩茨（Gompertz）、威布尔（Weibull）以及逻辑斯蒂（Logistic）三种衰老模型（Colchero等，2012）。针对每个膳食种群的每个性别，我们开展了三次BaSTA模拟（对应上述三种衰老模型各一次），每次模拟包含2200200次迭代，预烧期（burn-in）为200000条链，并每4000次迭代抽取一次马尔可夫链蒙特卡洛（Markov Chain Monte Carlo, MCMC）链样本。生存曲线则通过"survival"与"survminer"工具包，以默认参数设置绘制完成。