Campón Florencia Fernández
Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA.
Naturwissenschaften. 2010 Mar;97(3):279-89. doi: 10.1007/s00114-009-0640-8.
In species with widespread distribution, populations found in markedly different environments can show differences in developmental traits. This, in time, can have an effect on reproductive success. Sources of variation in developmental traits can be genetic or environmentally induced. I examined the relationship between environmental and genetic influences on juvenile development in populations of the colonial spider, Parawixia bistriata, located at sites with different moisture regimes and associated environmental variables (e.g., prey availability). It was expected that individuals from different populations would show differences in developmental traits and that those differences will be associated with lower reproductive success at dry sites. I recorded the phenology and developmental traits of native and transplanted individuals in the field and estimated reproductive success based on clutch size. Colonies from wet versus dry sites showed different phenologies, with individuals at dry sites maturing later. Transplant results suggest plasticity in instar duration caused by environmental effects. Despite differences in resources and spider phenology, clutch sizes of native dry and wet populations were similar. Transplanted individuals, however, were differentially affected. Transplants from wet to dry sites (WD) showed lower growth rates and smaller clutches, whereas transplants from dry to wet sites had larger clutch sizes than in native habitat. Delayed maturation and failure to reproduce in WD individuals is associated with a lower tendency to capture prey in groups and less aggressive interactions during prey capture. Thus, despite negative environmental effects on development, dry native individuals have evolved non-developmental traits that allow successful reproduction.
在分布广泛的物种中，处于明显不同环境中的种群在发育特征上可能会表现出差异。随着时间的推移，这可能会对繁殖成功率产生影响。发育特征的变异来源可能是遗传的，也可能是由环境诱导的。我研究了环境和遗传因素对群居蜘蛛Parawixia bistriata种群中幼体发育的影响，这些种群位于具有不同湿度条件及相关环境变量（如猎物可获得性）的地点。预计来自不同种群的个体在发育特征上会表现出差异，并且这些差异将与干旱地区较低的繁殖成功率相关。我在野外记录了本地个体和移植个体的物候和发育特征，并根据卵块大小估计繁殖成功率。来自湿润地区与干旱地区的种群表现出不同的物候，干旱地区的个体成熟较晚。移植结果表明环境效应导致龄期持续时间具有可塑性。尽管资源和蜘蛛物候存在差异，但本地干旱和湿润种群的卵块大小相似。然而，移植个体受到的影响有所不同。从湿润地区移植到干旱地区（WD）的个体生长速率较低且卵块较小，而从干旱地区移植到湿润地区的个体卵块大小比在原生栖息地时更大。WD个体成熟延迟和繁殖失败与群体捕食猎物的倾向较低以及捕食过程中攻击性互动较少有关。因此，尽管环境对发育有负面影响，但干旱地区的本地个体已经进化出非发育特征以实现成功繁殖。
