Data from: A treefrog with reproductive mode plasticity reveals a changing balance of selection for non-aquatic egg-laying

Non-aquatic reproduction has evolved repeatedly, but the factors that select for laying eggs on land are not well understood. The treefrog Dendropsophus ebraccatus has plasticity in reproductive mode, laying eggs that successfully develop in or out of water. This permits the first experimental comparison of the selective agents that shape adult oviposition behavior and embryo developmental capacity. I quantified the sources and strength of arboreal and aquatic egg mortality, how mortality varies with weather patterns, and assessed 39 years of daily rainfall patterns to infer historic levels of egg mortality and effects of climate change on the selective balance between aquatic and non-aquatic egg deposition. Aquatic predators and desiccation were the strongest selective agents in water and air, respectively. Egg mortality varied with weather such that aquatic oviposition was advantageous when rainfall was low, but laying eggs out of water increased survival when rainfall was high. Additionally, I found that since 1972 there have been significant changes in the patterns of rainfall in central Panama, which has altered the selective landscape acting on egg-laying behavior. This work provides insight into both the evolution and maintenance of adaptive phenotypic plasticity as well as historic and current selection on reproduction.

非水生繁殖模式已多次独立演化，但驱动物种选择在陆地产卵的选择因子尚未得到充分阐释。细纹树蛙（Dendropsophus ebraccatus）具备繁殖模式的表型可塑性，其产出的卵可在水环境或陆生生境中成功发育。这一特性为开展首个针对调控成体产卵行为与胚胎发育能力的选择因子的实验比较研究提供了可能。本研究量化了树栖卵与水生卵的死亡来源及其作用强度，分析了死亡率随天气格局的变化规律，并通过解析39年的日降雨数据集，推断了历史时期的卵死亡率水平，以及气候变化对水生与非水生产卵选择平衡的影响。研究发现，水生捕食者与干燥脱水分别是水环境与陆生生境中最强的选择压力。卵死亡率随天气条件呈现显著波动：低降雨情境下水生产卵具备生存优势，而高降雨条件下陆地产卵可提升卵的存活率。此外，自1972年以来，巴拿马中部的降雨模式已发生显著改变，这一变化重塑了作用于产卵行为的选择压力格局。本研究既为适应性表型可塑性的演化与维持机制提供了新的认知视角，也为繁殖相关的历史与当代选择压力研究提供了重要参考。