Hormonal pleiotropy and the evolution of allocation trade-offs

Recent empirical evidence suggest that trade-off relationships can evolve, challenging the classical image of their high entrenchment. For energy reliant traits, this relationship should depend on the endocrine system that regulates resource allocation. Here we model changes in this system by mutating the expression and conformation of its constitutive hormones and receptors. We show that the shape of trade-offs can indeed evolve in this model through the combined action of genetic drift and selection, such that their evolutionarily expected curvature and length depend on context. In particular, the shape of a trade- off should depend on the cost associated with resource storage, itself depending on the traded resource and on the ecological context. Despite this convergence at the phenotypic level, we show that a variety of physiological mechanisms may evolve in similar simulations, suggesting redundancy at the genetic level. This model should provide a useful framework to interpret and...

最新的实证研究证据表明，权衡（trade-off）关系可以发生演化，这对认为其高度固化的经典认知构成了挑战。对于依赖能量的性状而言，这类权衡关系应取决于调控资源分配的内分泌系统。本研究通过诱变该系统中组成型激素与受体的表达与构象，对其变化进行建模。我们证实，在该模型中，权衡的形态确实可通过遗传漂变与自然选择的共同作用发生演化，使其演化预期的曲率与长度随情境而异。具体而言，权衡的形态应取决于与资源储存相关的成本，而该成本本身又取决于被分配的资源与生态情境。尽管表型层面存在这种趋同性，但我们发现，在相似的模拟实验中可演化出多种不同的生理机制，这暗示遗传层面存在冗余性。该模型将为解读与……提供一个颇具价值的研究框架。