Physiol Biochem Zool. 2020 Nov/Dec;93(6):450-465. doi: 10.1086/711956.
AbstractResource-intensive traits, such as dispersal and reproduction, can be difficult to express simultaneously because of resource limitations. One solution is to switch between resource-intensive behaviors. Such phenotypic plasticity is one strategy that organisms use to funnel resources from one expensive trait to another. In crickets (), the development and maintenance of flight muscles reduce resource availability for reproduction, leading to physiological trade-offs between the two traits. Long-winged female can histolyze their wing muscles, resulting in increased egg production, but they can then no longer fly. Using a diet that mimics food availability in the field, we found that long-winged females adopted one of the three following strategies: early reproduction, intermediate reproduction, and late reproduction. Some late reproducers maintained their flight capability until the end of their natural life span and laid few eggs. If females lost the ability to fly (i.e., their hind wings are removed), they laid eggs earlier, leading to increased reproductive output. However, other environmental cues (e.g., an increased number of mates, increased oviposition substrate quality, or a bout of dispersal flight) had no effect. Late-reproducing females laid 96% fewer eggs than early reproducers, suggesting that late reproduction exacts a huge fitness cost. Nevertheless, some females maintain their flight muscles to the end of their natural life span in both the lab and the field. We suggest that the ability to fly allows for bet hedging against an environmental catastrophe (e.g., drought or flood). This benefit may help explain the persistence of late-reproducing long-winged females, despite the cost of this choice. As climate change increases drought and flood in Texas, late dispersal may be one factor that helps this species survive in the future. An increased understanding of factors that maintain seemingly low fitness strategies can help us predict the resilience of species under climate change.
摘要
资源密集型特征，如扩散和繁殖，由于资源限制，可能难以同时表达。一种解决方案是在资源密集型行为之间切换。这种表型可塑性是生物体用于将资源从一种昂贵的特征转移到另一种特征的策略之一。在蟋蟀（）中，飞行肌肉的发育和维持会减少繁殖的资源可用性，导致这两个特征之间的生理权衡。长翅的雌性可以分解它们的翅膀肌肉，从而增加产卵量，但它们就无法再飞行了。使用一种模仿野外食物可获得性的饮食，我们发现长翅的雌性采用了以下三种策略之一：早期繁殖、中期繁殖和晚期繁殖。一些晚期繁殖者一直保持着飞行能力，直到其自然寿命结束，并且产卵很少。如果雌性失去了飞行能力（即，它们的后翅被切除），它们会更早产卵，从而增加繁殖量。但是，其他环境线索（例如，增加伴侣数量、增加产卵基质质量或一次扩散飞行）没有效果。晚期繁殖的雌性产卵量比早期繁殖的雌性少 96%，这表明晚期繁殖会产生巨大的适应代价。然而，一些雌性在实验室和野外都将飞行肌肉维持到其自然寿命结束。我们认为，飞行能力允许对环境灾难（例如干旱或洪水）进行赌注。这种好处可能有助于解释尽管这种选择代价高昂，但晚期繁殖的长翅雌性仍然存在的原因。随着德克萨斯州气候变化导致干旱和洪水的增加，晚期扩散可能是帮助该物种在未来生存的一个因素。对维持看似低适应力策略的因素的更多了解，可以帮助我们预测物种在气候变化下的恢复能力。
