Speciation and anagenesis in the genus Cyprinella of Mexico (Teleostei: Cyprinidae): a case study of Model III allopatric speciation
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- Wood, R.M. & Mayden, R.L. Reviews in Fish Biology and Fisheries (2002) 12: 253. doi:10.1023/A:1025018118339
Allozyme variation at 42 presumptive gene lociis presented for members of the C. formosa species group. This group iscorroborated as a monophyletic assemblage whosecommon ancestor occupied pluvial Lake Palomasof the Guzman Basin. With increasingaridity during the Pleistocene this basin andassociated populations of this commonancestor were fragmented into several lineagesthat diverged independently of oneanother. The pattern of relationships andlevels of anagenetic change observed inindependent lineages for this clade are notconsistent with expectations of the mostcommon modes of speciation, Model I large-scalevicariance or Model II peripheralisolation. Rather, divergence in these fishlineages is consistent with the rarely observedModel III allopatric speciation. Consistentwith predictions of this model, thephylogenetic pattern recovered revealspolychotomous relationships (a hard polytomy)and varied rates of anagenetic change acrossexamined lineages.