The Northern Flicker Hybrid Zone

北方闪光是研究物种形成进化过程的模型。两个相当不同的亚种在大平原西部的范围重叠，在那里它们形成了一个广泛的杂交区域。尽管这两个亚种进行了广泛的杂交，亚种的清晰度仍然保持不变。以往的工作有力地表明，选择是维持杂交区两个亚种特征的主要力量。目前的研究旨在确定自然选择还是性选择是最重要的。自然选择将以与杂交区相关的生态变量的形式出现，而性选择将反映亚种在其原生范围之外建立繁育区域的能力。解决这些问题将促进我们对物种形成是如何发生的，以及如何在如此短的时间内进化出如此多的多样性的理解。

The Northern Flicker serves as a model for studies on the evolutionary process of speciation. The ranges of two rather distinct subspecies overlap on the western Great Plains where they form an extensive hybrid zone. The distinctness of the subspecies is maintained even though the two hybridize extensively. Previous work strongly suggests that selection is a major force in maintaining the characteristics of the two subspecies across the hybrid zone. Current research is designed to determine whether natural selection or sexual selection is most important. Natural selection would be in the form of ecological variables associated with the hybrid zone whereas sexual selection would reflect the ability of the subspecies to establish breeding territories outside of their native ranges. Resolving these questions will advance our understanding of how speciation occurs and how so much diversity evolves in such a short time.