Open AccessGenetic differentiation, speciation, and phylogeography of cactus flies ( D iptera: N eriidae: O dontoloxozus ) from M exico and south‐western USA
Author(s) -
Pfeiler Edward,
Richmond Maxi Polihronakis,
RiesgoEscovar Juan R.,
TellezGarcia Aldo A.,
Johnson Sarah,
Markow Therese A.
Publication year - 2013
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/bij.12133
Subject(s) - biology , vicariance , phylogeography , gene flow , genetic structure , phylogenetic tree , ecology , isolation by distance , evolutionary biology , population , species complex , zoology , genetic variation , gene , genetics , demography , sociology
Nucleotide sequences from the mitochondrial cytochrome c oxidase subunit I ( COI ) gene, comprising the standard barcode segment, were used to examine genetic differentiation, systematics, and population structure of cactus flies ( D iptera: N eriidae: O dontoloxozus ) from M exico and south‐western USA . Phylogenetic analyses revealed that samples of O dontoloxozus partitioned into two distinct clusters: one comprising the widely distributed O dontoloxozus longicornis ( C oquillett) and the other comprising O dontoloxozus pachycericola M angan & B aldwin, a recently described species from the C ape R egion of the B aja C alifornia peninsula, which we show is distributed northward to southern C alifornia, USA . A mean K imura two‐parameter genetic distance of 2.8% between O . longicornis and O. pachycericola , and eight diagnostic nucleotide substitutions in the COI gene segment, are consistent with a species‐level separation, thus providing the first independent molecular support for recognizing O. pachycericola as a distinct species. We also show that the only external morphological character considered to separate adults of the two species (number of anepisternal bristles) varies with body size and is therefore uninformative for making species assignments. Analysis of molecular variance indicated significant structure among populations of O . longicornis from three main geographical areas, (1) A rizona, USA and S onora, M exico; (2) S anta C atalina I sland, C alifornia, USA ; and (3) central M exico ( Q uerétaro and G uanajuato), although widely‐separated populations from A rizona and S onora showed no evidence of structure. A TCS haplotype network showed no shared haplotypes of O . longicornis among the three main regions. The potential roles of vicariance and isolation‐by‐distance in restricting gene flow and promoting genetic differentiation and speciation in O dontoloxozus are discussed. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society , 2013, 110 , 245–256.