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Phylogeography of a specialist insect, Adelges cooleyi : historical and contemporary processes shape the distribution of population genetic variation
Author(s) -
AHERN ROBERT G.,
HAWTHORNE DAVID J.,
RAUPP MICHAEL J.
Publication year - 2009
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1111/j.1365-294x.2008.04034.x
Subject(s) - biology , phylogeography , gene flow , genetic variation , amplified fragment length polymorphism , mitochondrial dna , evolutionary biology , population , insect , population genetics , analysis of molecular variance , ecology , zoology , genetic diversity , phylogenetics , genetics , gene , demography , sociology
Adelges cooleyi is a host‐alternating, gall‐making insect native to the Rocky Mountains and Cascade Mountains in western North America. The insect's primary hosts are Picea (spruce) species, and its secondary host is Pseudotsuga menziesii , Douglas fir. To determine whether there are large‐scale patterns of genetic variation in this specialist insect, we created molecular phylogenies of geographically separate samples of A. cooleyi using sequence data from two mitochondrial (mtDNA) genes and amplified fragment length polymorphisms (AFLPs). Three divergent mtDNA lineages were identified. Analysis of mtDNA and AFLP genetic variation revealed that samples from southeastern Arizona are genetically isolated from all other samples. AFLP data identified possible gene flow between individuals from divergent mtDNA lineages in an area in the central Rocky Mountains. Factors that likely affected divergence within A. cooleyi were identified by comparing our conclusions with well‐known changes in the distribution of vegetation in response to glaciations and previous phylogeographical work conducted on this specialist insect's host‐plants. In addition to documenting previously unknown patterns of genetic variation in A. cooleyi , our work provides the basis for a testable hypothesis regarding the extent to which the distribution of variation in Picea and Pseudotsuga hosts mediates the distribution of genetic variation for this specialist insect.