Confer John L, Porter Cody, Aldinger Kyle R, Canterbury Ronald A, Larkin Jeffery L, Mcneil Darin J
Department of Biology Ithaca College Ithaca NY USA.
Department of Zoology and Physiology University of Wyoming Laramie WY USA.
Ecol Evol. 2020 Sep 24;10(19):10633-10644. doi: 10.1002/ece3.6717. eCollection 2020 Oct.
Extensive range loss for the Golden-winged Warbler () has occurred in areas of intrusion by the Blue-winged Warbler () potentially related to their close genetic relationship. We compiled data on social pairing from nine studies for 2,679 resident to assess evolutionary divergence. Hybridization between pure phenotypes occurred with 1.2% of resident males for sympatric populations. Pairing success rates for Golden-winged Warblers was 83% and for Blue-winged Warblers was 77%. Pairing success for the hybrid Brewster's Warbler was significantly lower from both species at 54%, showing sexual selection against hybrids. Backcross frequencies for Golden-winged Warblers at 4.9% were significantly higher than for Blue-winged Warblers at 1.7%. More frequent backcrossing by Golden-winged Warblers, which produces hybrid phenotypes, may contribute to the replacement of Golden-winged by Blue-winged Warblers. Reproductive isolation due to behavioral isolation plus sexual selection against hybrids was 0.960. Our analyses suggest that plumage differences are the main driving force for this strong isolation with reduced hybrid fitness contributing to a lesser degree. The major impact of plumage differences to reproductive isolation is compatible with genomic analyses (, 2016, 26, 2313), which showed the largest genetic difference between these phenotypes occurred with plumage genes. These phenotypes have maintained morphological, behavioral, and ecological differences during two centuries of hybridization. Our estimate of reproductive isolation supports recognition of these phenotypes as two species. The decline and extirpation of the Golden-winged Warbler in almost all areas of recent sympatry suggest that continued coexistence of both species will require eco-geographic isolation.
金翅莺（）的广泛分布范围丧失发生在蓝翅莺（）入侵的区域，这可能与其密切的遗传关系有关。我们汇总了9项研究中关于2679只留鸟的社会配对数据，以评估进化分歧。同域种群中，1.2%的留鸟雄性出现了纯合表型之间的杂交现象。金翅莺的配对成功率为83%，蓝翅莺为77%。杂交的布鲁斯特莺的配对成功率显著低于这两个物种，为54%，表明存在对杂交种的性选择。金翅莺的回交频率为4.9%，显著高于蓝翅莺的1.7%。金翅莺更频繁的回交产生了杂交表型，这可能导致蓝翅莺取代金翅莺。行为隔离加上对杂交种的性选择导致的生殖隔离为0.960。我们的分析表明，羽色差异是这种强烈隔离的主要驱动力，杂交后代适应性降低的影响较小。羽色差异对生殖隔离的主要影响与基因组分析结果一致（，2016年，26卷，2313页），该分析表明这些表型之间最大的遗传差异出现在羽色基因上。在两个世纪的杂交过程中，这些表型在形态、行为和生态上一直存在差异。我们对生殖隔离的估计支持将这些表型认定为两个物种。在最近几乎所有同域分布的地区，金翅莺数量下降并局部灭绝，这表明两个物种要继续共存需要生态地理隔离。
