title: Strikingly variable divergence times inferred across an Amazonian butterfly 'suture zone'.
abstract: 'Suture zones' are areas where hybrid and contact zones of multiple taxa are clustered. Such zones have been regarded as strong evidence for allopatric divergence by proponents of the Pleistocene forest refugia theory, a vicariance hypothesis frequently used to explain diversification in the Amazon basin. A central prediction of the refugia and other vicariance theories is that the taxa should have a common history so that divergence times should be coincident among taxa. A suture zone for Ithomiinae butterflies near Tarapoto, NE Peru, was therefore studied to examine divergence times of taxa in contact across the zone. We sequenced 1619bp of the mitochondrial COI/COII region in 172 individuals of 31 species from across the suture zone. Inferred divergence times differed remarkably, with divergence between some pairs of widespread species (each of which may have two or more subspecies interacting in the zone, as in the genus Melinaea) being considerably less than that between hybridizing subspecies in other genera (for instance in Oleria). Our data therefore strongly refute a simple hypothesis of simultaneous vicariance and suggest that ongoing parapatric or other modes of differentiation in continuous forest may be important in driving diversification in Amazonia.
authors.affiliation: University College London, Galton Laboratory, 4 Stephenson Way, London NW1 2HE, UK.
authors.forename: Alaine
authors.initials: A
authors.lastname: Whinnett
authors.forename: Marie
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Keith R
authors.initials: KR
authors.lastname: Willmott
authors.forename: Nimiadina
authors.initials: N
authors.lastname: Herrera
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mallarino
authors.forename: Fraser
authors.initials: F
authors.lastname: Simpson
authors.forename: Mathieu
authors.initials: M
authors.lastname: Joron
authors.forename: Gerardo
authors.initials: G
authors.lastname: Lamas
authors.forename: James
authors.initials: J
authors.lastname: Mallet
mesh_terms: D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D002080:Butterflies / Q000235:genetics*; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D005843:Geography; D006824:Hybridization, Genetic; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010568:Peru; D010802:Phylogeny; D011157:Population Dynamics; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial