609 8 archive 22 disk0/00/00/06/09 2014-01-27 11:57:19 2014-01-27 11:57:19 2014-01-27 11:57:19 article show david_tarkhnishvili@iliauni.edu.ge Tarkhnishvili David david_tarkhnishvili@iliauni.edu.ge Hille Axel BÖhme Wolfgang pub Evolution QEC QH426 QL ins5 none Brown frogs of the complex Rana macrocnemis demonstrate various degrees of differentiation between the two widespread forms, macrocnemis and camerani, in different parts of Anatolia, the Caucasus Isthmus and northern Iran. In order to reveal whether or not the forms represent monophyletic evolutionary lineages, we analysed the geographic distribution of characters of external morphology, alleles at three polymorphic allozyme loci and mitochondrial DNA haplotypes. All three character sets showed a highly congruent pattern in a limited area of humid forests in the south-west Caucasus. Frogs from this area (form macrocnemis) represent a monophyletic lineage which forms a narrow hybrid zone with populations of camerani inhabiting the southern Caucasus and north-east Turkey. However, in other parts of the group's range, hybridization between the two lineages resulted in the merger of forms and the formation of a clinal pattern of variations. The role of landscape-dependent diversifying selection in the evolution of the group is discussed. Conceptual difficulties in delimiting the borders of subspecies are pointed out. 2001-10 published Biological Journal of the Linnean Society 74 2 Wiley-Blackwell 141-156 10.1111/j.1095-8312.2001.tb01383.x TRUE 1095-8312 http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2001.tb01383.x/abstract;jsessionid=8808B08B11E58DD0004861E73CB92A09.f02t01?deniedAccessCustomisedMessage=&userIsAuthenticated=false Alexander von Humboldt Stieftung