Data from: Royal Darwinian demons: enforced changes in reproductive efforts do not affect the life expectancy of ant queens

One of the central tenets of life-history theory is that organisms cannot simultaneously maximize all fitness components. This results in the fundamental trade-off between reproduction and life span known from numerous animals, including humans. Social insects are a well-known exception to this rule: reproductive queens outlive nonreproductive workers. Here, we take a step forward and show that under identical social and environmental conditions the fecundity-longevity trade-off is absent also within the queen caste. A change in reproduction did not alter life expectancy, and even a strong enforced increase in reproductive efforts did not reduce residual life span. Generally, egg-laying rate and life span were positively correlated. Queens of perennial social insects thus seem to maximize at the same time two fitness parameters that are normally negatively correlated. Even though they are not immortal, they best approach a hypothetical “Darwinian demon” in the animal kingdom.

生活史理论（life-history theory）的核心信条之一为：生物体无法同时最大化所有适合度组分（fitness components）。由此催生了繁殖与寿命间的根本性权衡（trade-off），这一现象已在包括人类在内的诸多动物中被广泛报道。社会性昆虫（social insects）是该规则的广为人知的例外：具有繁殖能力的蚁后（reproductive queens）的寿命长于不育工虫（nonreproductive workers）。本研究在此基础上进一步表明，在一致的社会与环境条件下，蚁后品级（queen caste）内部同样不存在繁殖力-寿命权衡（fecundity-longevity trade-off）。繁殖水平的改变并未影响个体预期寿命，即便通过人工强制大幅提升繁殖投入，也未缩短剩余寿命（residual life span）。总体而言，产卵率与寿命呈正相关。因此，多年生社会性昆虫的蚁后似乎能够同时最大化通常呈负相关的两项适合度参数（fitness parameters）。尽管它们并非永生，但已是动物界最接近假想"达尔文恶魔（Darwinian demon）"的类群。