Hybridization and introgression can have complex consequences for both species evolution and conservation. Here, we investigated the origin and characteristics of a putative hybrid zone between two South American poison dart frog species, Oophaga anchicayensis and the critically endangered Oophaga lehmanni , which are heavily sought after on the illegal pet market. Using a combination of phenotypic (49 traits) and genomic (ddRADseq) data, we found that the putative hybrids are morphologically distinct from their parental species and confirmed genomic signatures of admixture in these populations. Several lines of evidence (hybrid indices, interspecific hybrid heterozygosity, genomic clines, comparisons with simulated hybrids and demographic modelling) support the conclusion that these populations are not comprised of early‐generation hybrids and thus, they probably did not arise as a result of illegal translocations associated with wildlife trafficking. Instead, they probably represent an independent lineage which has persisted through isolation and has only relatively recently re‐established gene flow with both parental species. Furthermore, we detected signals of differential introgression from parental species into these hybrid populations which suggest relaxed stabilizing selection on these aposematic colour morphs, potentially via context‐dependent female choice. These populations thus provide a fascinating window into the role of hybridization, isolation and female choice in the diversification of South American poison dart frogs. In addition, our results underline the importance of landscape conservation measures to protect, not only known localities of nominal species, but also the phenotypic and genomic variation harbored by admixed lineages which represent crucial repositories for the impressive diversity in this system.

中文翻译：

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在Oophaga毒蛙中，复杂的分化和基因流模式在定性表型的差异性上处于潜在地位。

杂交和渗入会对物种进化和保护产生复杂的影响。在这里，我们调查了两种南美毒箭蛙物种Oophaga anchicayensis和极度濒危的Oophaga lehmanni之间的推定杂种区的起源和特征。，在非法宠物市场上备受追捧。使用表型（49个性状）和基因组（ddRADseq）数据的组合，我们发现推定的杂种在形态上不同于其亲本物种，并在这些种群中证实了混合物的基因组特征。有几条证据（杂交指数，种间杂种杂合性，基因组谱系，与模拟杂种的比较和人口统计学建模）支持以下结论：这些种群不包括早期杂种，因此，它们可能不是由于非法而产生的与野生动植物贩运有关的易位。取而代之的是，它们可能代表了一个独立的世系，该世系一直通过分离而持续存在，并且直到最近才与两个亲代物种重新建立了基因流。此外，我们检测到了从亲本种向这些杂种群体渗入的差异渗入信号，这表明可能通过上下文相关的雌性选择对这些成虫颜色形态进行轻松的稳定选择。因此，这些种群为杂交，隔离和雌性选择在南美毒箭蛙多样化中的作用提供了一个迷人的窗口。此外，我们的结果强调了景观保护措施的重要性，不仅要保护标称物种的已知地区，而且要保护混合谱系所具有的表型和基因组变异，这些谱系是该系统令人印象深刻的多样性的重要存储库。