Swenson N G
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.
J Evol Biol. 2006 May;19(3):717-25. doi: 10.1111/j.1420-9101.2005.01066.x.
The existence of suture zones in North America has recently been verified, yet the environmental factors responsible for the maintenance of their structure and position have remained undetermined. The Great Plains suture zone in the US is perhaps the most significant and broadly studied in North America. Numerous avian hybrid zones that cluster in this region have been extensively studied over the last half-century. A primary result of this work is that exogenous factors present in this region have promoted and maintained avian species divergence. Yet, to date the variables most important in the generation and the clustered positioning of these hybrid zones in relation to one another have not been determined. The present study aims to advance our understanding of this North American suture zone by using niche modelling to quantify which environmental variables are most important in its formation and maintenance. Through the generation of fundamental niches for four hybrids and their parental species, similarities linking the hybrid zones were uncovered. The results show that temperature holds this suture zone in position and also suggest that temperature played a primary role in promoting niche differentiation among these sister species pairs during Pleistocene glacial cycles.
北美缝合带的存在最近已得到证实，但其结构和位置得以维持的环境因素仍未确定。美国的大平原缝合带可能是北美最重要且研究最为广泛的缝合带。在过去半个世纪里，大量聚集在该地区的鸟类杂交带得到了广泛研究。这项工作的一个主要成果是，该地区存在的外部因素促进并维持了鸟类物种的分化。然而，迄今为止，对于这些杂交带的形成以及彼此间聚集定位最为重要的变量尚未确定。本研究旨在通过利用生态位建模来量化哪些环境变量对其形成和维持最为重要，从而增进我们对这个北美缝合带的理解。通过为四个杂交种及其亲本物种生成基础生态位，发现了连接杂交带的相似性。结果表明，温度使这条缝合带处于当前位置，还表明在更新世冰川周期中，温度在促进这些姊妹物种对之间的生态位分化方面发挥了主要作用。
