Data from: Sympatric, temporally isolated populations of the pine white butterfly Neophasia menapia, are morphologically and genetically differentiated

Temporal isolation remains an understudied, and potentially under-appreciated, mechanism of reproductive isolation. Phenological differences have been discovered in populations of the pine white butterfly (Neophasia menapia), a typically univoltine species found throughout western North America. At two locations in the Coast Range of California there are two periods of adult emergence per year, one in early summer (July) and one in late summer/autumn (September/October). Differences in flight time are accompanied by differences in wing shape and pigmentation. Here we use a combination of population genomics and morphological analyses to assess the extent to which temporal isolation is able to limit gene flow between sympatric early and late flights. Not only did we detect both genetic and morphological differences between early and late flights at the two sites, we also found that the patterns of differentiation between the two flights were different at each location, suggesting an independent origin for the two sympatric flights. Additionally, we found no evidence that these sympatric flights originated via colonization from any of the other sampled localities. We discuss several potential hypotheses about the origin of these temporally isolated sympatric flights.

时间隔离仍是一种研究不足、且可能未得到足够重视的生殖隔离机制。在松树白蝶（Neophasia menapia）的种群中已发现物候差异，该物种为典型的一化性昆虫，广泛分布于北美西部。在加利福尼亚海岸山脉的两个采样点中，该种群每年存在两个成虫羽化高峰期：分别为初夏（7月）与夏末/秋季（9月/10月）。羽化时间的差异同时伴随翅形与色素沉着的差异。本研究结合种群基因组学与形态学分析方法，旨在评估时间隔离对同域早羽化群与晚羽化群之间基因流的限制程度。本研究不仅在两个采样点的早、晚羽化群中检测到遗传与形态学差异，还发现两个羽化群的分化模式在两个采样点间存在差异，表明这两对同域羽化群具有独立的起源。此外，本研究未发现证据表明这些同域羽化群源自其他采样点的种群定殖。本研究还就这些时间隔离型同域羽化群的起源探讨了若干潜在假说。