Cronin Andrew D, Smit Judith A H, Ellers Jacintha, Halfwerk Wouter
Amsterdam Institute for Life and Environment, Section Ecology and Evolution, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Smithsonian Tropical Research Institute, Balboa, Ancón, Panama.
J Anim Ecol. 2025 Jun 29. doi: 10.1111/1365-2656.70071.
Urbanisation is rapidly altering environments with severe impacts on life on earth. While impacts from urbanisation are widespread, organisms with metamorphic life cycles are particularly likely to be affected, as they often undergo a major shift in lifestyle and habitat across life stages. Early life stages also likely undergo exceptionally high selection due to elevated mortality rates. Despite the potential importance of these early stages, we often lack insight into how urban conditions influence individuals early in their development. This study examined how exposure to urban environmental conditions alters developmental phenotypes in interaction with origin. We studied túngara frog tadpoles (Engystomops pustulosus) from urban and forest populations and conducted a reciprocal transplant between forest and urban treatments. Wild collected breeding pairs from urban and forest populations created clutches produced in the lab. Clutches were then split in two and exposed for 2 weeks to urban or forest developmental conditions. Tadpole developmental timing, morphology and vigilance behaviour were subsequently measured to assess the effects of origin and treatment, as well as their interaction. Urban developmental environments differ in water quality, are warmer, and have fewer predators compared to forest environments. Our findings demonstrate that tadpoles originating from urban populations have a faster developmental rate regardless of the environmental treatment. Tadpoles exposed to the urban environment have constrained growth compared to tadpoles exposed to the forest environment, independent of origin. Additionally, we find that urban origin tadpoles demonstrate increased behavioural plasticity in response to disturbance compared to forest origin tadpoles. Our results show effects of urban conditions on developmental phenotypes both within and across generations, most likely as an adaptive response to higher aquatic temperature regimes in urban areas. Divergence in juvenile growth and development may underlie divergence in adult phenotypes typical of adult túngara frogs found in urban and forest areas. These findings demonstrate the need to integrate early developmental stages to fully understand the evolutionary and ecological implications of urbanisation.
城市化正在迅速改变环境，对地球上的生命产生严重影响。虽然城市化的影响广泛存在，但具有变态生命周期的生物尤其容易受到影响，因为它们在生命阶段往往会经历生活方式和栖息地的重大转变。由于死亡率升高，早期生命阶段也可能经历异常高的选择压力。尽管这些早期阶段具有潜在的重要性，但我们通常缺乏对城市环境如何影响个体早期发育的深入了解。本研究考察了暴露于城市环境条件下如何与起源相互作用改变发育表型。我们研究了来自城市和森林种群的斑腿泛树蛙蝌蚪（Engystomops pustulosus），并在森林和城市处理之间进行了相互移植实验。从城市和森林种群中野外采集繁殖对，在实验室中产生卵块。然后将卵块分成两部分，分别在城市或森林发育条件下暴露2周。随后测量蝌蚪的发育时间、形态和警戒行为，以评估起源和处理的影响以及它们的相互作用。与森林环境相比，城市发育环境的水质不同，温度更高，捕食者更少。我们的研究结果表明，无论环境处理如何，来自城市种群的蝌蚪发育速度更快。与暴露于森林环境的蝌蚪相比，暴露于城市环境的蝌蚪生长受到限制，与起源无关。此外，我们发现与森林起源的蝌蚪相比，城市起源的蝌蚪在受到干扰时表现出更大的行为可塑性。我们的结果显示了城市条件对代内和代际发育表型的影响，最有可能是对城市地区较高水温环境的适应性反应。幼体生长和发育的差异可能是城市和森林地区成年斑腿泛树蛙典型成年表型差异的基础。这些发现表明，需要整合早期发育阶段，以充分理解城市化的进化和生态影响。
