Fluctuations in population composition dampen the impact of phenotypic plasticity on trait dynamics in superb fairy-wrens.
Fluctuations in population composition dampen the impact of phenotypic plasticity on trait dynamics in superb fairy-wrens.
复制标题
种群组成的波动减弱了表型可塑性对优良细尾鹪鹩性状动态的影响。
DOI：
10.1111/j.1365-2656.2011.01919.x
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
A. Cockburn
中科院分区：
文献类型：
--
作者：
Martijn van de Pol;Helen L. Osmond;A. Cockburn
1.在结构化种群中，表型变化可由个体一生的变化(表型可塑性、与年龄有关的变化)、选择和种群构成的变化(环境或密度驱动的年龄结构波动)引起。2.种群动态对表型变化的贡献往往被忽视。然而，为了理解特征动态，重要的是要确定导致特征变化的个体和群体水平的机制，因为它们可能相互促进或相互抵消。3.利用22年的野外资料，研究了一种性选择物候性状的动态-的研究4.我们发现，性状的表达既依赖于气候，也依赖于年龄，但对气候变异性的表型可塑性也随年龄而变化。大雨量过后，年长的雄性可以很早就长出婚礼羽毛，但1到2岁的孩子却不能。然而，所有年龄段的雄性将蜕皮推迟到今年晚些时候，在条件较暖和的时候更早获得婚礼羽毛。5.潜在的机制似乎是，老年雄性可能在一年中最具挑战性的时期--秋季--干旱限制食物丰富和寒冷的冬季--冒着蜕皮的风险。相比之下，年轻的雄性总是在春季过渡到温和温暖和通常更潮湿的条件下蜕皮。温度变化主导着这一转变，这预示着繁殖季节的到来，从而导致幼鸟和晚换羽的老鸟都对温度敏感。6.气候和年龄也通过群体动力学途径影响性状动态。引发老年雄性早期蜕皮的高降雨量同时增加了后代的招募，从而降低了种群中雄性的平均年龄。因此，降雨通过老年雄性的表型可塑性对性状动态的影响被年龄结构的同步恢复所抑制。7.由于可塑性，环境变得更加干燥的长期趋势促使表型变化，但这被气候驱动的人口变化所掩盖(造成明显的停滞)。这提出了一种新的解释，解释了为什么性状变化可能无法反映所观察到的方向选择或表型可塑性的模式。
1. In structured populations, phenotypic change can result from changes throughout an individual's lifetime (phenotypic plasticity, age-related changes), selection and changes in population composition (environment- or density-driven fluctuations in age-structure). 2. The contribution of population dynamics to phenotypic change has often been ignored. However, for understanding trait dynamics, it is important to identify both the individual- and population-level mechanisms responsible for trait change, because they potentially reinforce or counteract each other. 3. We use 22 years of field data to investigate the dynamics of a sexually selected phenological trait, the timing of nuptial moult in superb fairy-wrens Malurus cyaneus. 4. We show that trait expression is both climate- and age-dependent, but that phenotypic plasticity in response to climate variability also varies with age. Old males can acquire nuptial plumage very early after high rainfall, but 1- to 2-year-olds cannot. However, males of all ages that defer moult to later in the year acquire nuptial plumage earlier when conditions are warmer. 5. The underlying mechanism appears to be that old males may risk moulting in the most challenging period of the year: in autumn, when drought restricts food abundance and during the cold winter. By contrast, young males always moult during the spring transition to benign - warmer and generally wetter - conditions. Temperature changes dominate this transition that heralds the breeding season, thereby causing both young and late-moulting older birds to be temperature sensitive. 6. Climate and age also affect trait dynamics via a population dynamical pathway. The same high rainfall that triggers early moulting in old males concurrently increases offspring recruitment and thereby reduces the average age of males in the population. Consequently, effects of rainfall on trait dynamics through phenotypic plasticity of old males are dampened by synchronous rejuvenation of the age-structure. 7. A long-term trend towards drier environments prompted phenotypic change because of plasticity, but this was masked by climate-driven demographic change (causing apparent stasis). This suggests a novel explanation for why trait change may fail to reflect the observed pattern of directional selection or phenotypic plasticity.