Robustness against environmental fluctuations within an adaptive state should preclude exploration of new adaptive states when the environment changes. Here, we study transitions between adaptive associations of feather structure and carotenoid uptake to understand how robustness and evolvability can be reconciled. We show that feather modifications induced by unfamiliar carotenoids during a range expansion are repeatedly converted into precise coadaptations of feather development and carotenoid accommodation as populations persist in a region. We find that this conversion is underlain by a uniform and coordinated increase in the sensitivity of feather development to local carotenoid uptake, indicative of cooption and modification of the homeostatic mechanism that buffers feather growth in the evolution of new adaptations. Stress-buffering mechanisms are well placed to alternate between robustness and evolvability and we suggest that this is particularly evident in adaptations that require close integration between widely fluctuating external inputs and intricate internal structures.

当环境变化时，针对适应性状态内的环境波动的鲁棒性应排除探索新的适应性状态的可能性。在这里，我们研究羽毛结构和类胡萝卜素摄取的适应性关联之间的过渡，以了解如何协调鲁棒性和可进化性。我们显示，在范围扩展期间，由陌生类胡萝卜素引起的羽毛修饰在范围扩展中反复转化为羽毛发育和类胡萝卜素适应的精确共适应。我们发现这种转变是由羽毛发育对局部类胡萝卜素摄取的敏感性的统一和协调增加所支撑的，这表明在新适应性进化中缓冲羽毛生长的稳态机制的共同选择和修改。