Coalescent analyses show isolation without migration in two closely related tropical orioles: the case of Icterus graduacauda and Icterus chrysater

Ecology and Evolution

Nandadevi Cortés-Rodríguez²  Frode Jacobsen²  Blanca E. Hernandez-Baños¹  Adolfo G. Navarro-Siguenza¹  Jeffrey L. Peters³ 

[1] Museo de Zoología, Facultad de Ciencias, UNAM, México City, México;Department of Biological Sciences, University of Maryland-Baltimore County, Baltimore, Maryland;Department of Biological Sciences, Wright State University, Dayton, Ohio 45435

关键词: coalescent;    Icterus;    Isolation with Migration;    Isthmus of Tehuantepec;    multilocus;   

DOI  :  10.1002/ece3.768

来源: Wiley

【 摘 要 】

Abstract

The Isthmus of Tehuantepec has played an important role in shaping the avian diversity of Mexico, as well as the rest of the Western Hemisphere. It has been both a barrier and a land connector between North and South America for many groups of birds. Furthermore, climatic change over the Pleistocene has resulted in ecological fluctuations that led to periods of connection and isolation of the highlands in this area. Here we studied the divergence of two species of orioles whose distribution in the highlands is separated by the lowlands of the Isthmus of Tehuantepec: Icterus graduacauda (west of the Isthmus) and Icterus chrysater (east of the Isthmus). We sequenced multiple loci (one mitochondrial gene and six nuclear introns) and performed coalescent analyses (Isolation with Migration) to test whether their divergence resulted from prior occupancy of the ancestral area followed by a vicariant event or recent dispersal from one side or the other of this Isthmus. Results strongly indicate a vicariant event roughly 300,000 years ago in the Pleistocene followed by little or no gene flow. Both mitochondrial and nuclear genes show that the Isthmus of Tehuantepec is a strong barrier to gene flow. Thus, these two species appear to not exchange genes despite their recent divergence and the close geographic proximity of their ranges.

【 授权许可】

CC BY   
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

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