Open AccessHiding deep in the trees: discovery of divergent mitochondrial lineages in Malagasy chameleons of the Calumma nasutum group
Author(s) -
Gehring PhilipSebastian,
Tolley Krystal A.,
Eckhardt Falk Sebastian,
Townsend Ted M.,
Ziegler Thomas,
Ratsoavina Fanomezana,
Glaw Frank,
Vences Miguel
Publication year - 2012
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.269
Subject(s) - biology , coalescent theory , phylogenetic tree , clade , evolutionary biology , phylogenetics , lineage (genetic) , mitochondrial dna , taxonomy (biology) , taxonomic rank , dna barcoding , molecular phylogenetics , zoology , taxon , ecology , genetics , gene
Abstract We conducted a comprehensive molecular phylogenetic study for a group of chameleons from Madagascar (Chamaeleonidae: Calumma nasutum group, comprising seven nominal species) to examine the genetic and species diversity in this widespread genus. Based on DNA sequences of the mitochondrial gene ( ND2 ) from 215 specimens, we reconstructed the phylogeny using a Bayesian approach. Our results show deep divergences among several unnamed mitochondrial lineages that are difficult to identify morphologically. We evaluated lineage diversification using a number of statistical phylogenetic methods (general mixed Yule‐coalescent model; SpeciesIdentifier; net p ‐distances) to objectively delimit lineages that we here consider as operational taxonomic units (OTUs), and for which the taxonomic status remains largely unknown. In addition, we compared molecular and morphological differentiation in detail for one particularly diverse clade (the C. boettgeri complex) from northern Madagascar. To assess the species boundaries within this group we used an integrative taxonomic approach, combining evidence from two independent molecular markers ( ND2 and CMOS ), together with genital and other external morphological characters, and conclude that some of the newly discovered OTUs are separate species (confirmed candidate species, CCS), while others should best be considered as deep conspecific lineages (DCLs). Our analysis supports a total of 33 OTUs, of which seven correspond to described species, suggesting that the taxonomy of the C. nasutum group is in need of revision.