TY - JOUR
T1 - Isolation-driven divergence
T2 - Speciation in a widespread North American songbird (Aves: Certhiidae)
AU - Manthey, Joseph D.
AU - Klicka, John
AU - Spellman, Garth M.
PY - 2011/10
Y1 - 2011/10
N2 - Lineage, or true 'species', trees may differ from gene trees because of stochastic processes in molecular evolution leading to gene-tree heterogeneity. Problems with inferring species trees because of excessive incomplete lineage sorting may be exacerbated in lineages with rapid diversification or recent divergences necessitating the use of multiple loci and individuals. Many recent multilocus studies that investigate divergence times identify lineage splitting to be more recent than single-locus studies, forcing the revision of biogeographic scenarios driving divergence. Here, we use 21 nuclear loci from regional populations to re-evaluate hypotheses identified in an mtDNA phylogeographic study of the Brown Creeper (Certhia americana), as well as identify processes driving divergence. Nuclear phylogeographic analyses identified hierarchical genetic structure, supporting a basal split at approximately 32°N latitude, splitting northern and southern populations, with mixed patterns of genealogical concordance and discordance between data sets within the major lineages. Coalescent-based analyses identify isolation, with little to no gene flow, as the primary driver of divergence between lineages. Recent isolation appears to have caused genetic bottlenecks in populations in the Sierra Madre Oriental and coastal mountain ranges of California, which may be targets for conservation concerns.
AB - Lineage, or true 'species', trees may differ from gene trees because of stochastic processes in molecular evolution leading to gene-tree heterogeneity. Problems with inferring species trees because of excessive incomplete lineage sorting may be exacerbated in lineages with rapid diversification or recent divergences necessitating the use of multiple loci and individuals. Many recent multilocus studies that investigate divergence times identify lineage splitting to be more recent than single-locus studies, forcing the revision of biogeographic scenarios driving divergence. Here, we use 21 nuclear loci from regional populations to re-evaluate hypotheses identified in an mtDNA phylogeographic study of the Brown Creeper (Certhia americana), as well as identify processes driving divergence. Nuclear phylogeographic analyses identified hierarchical genetic structure, supporting a basal split at approximately 32°N latitude, splitting northern and southern populations, with mixed patterns of genealogical concordance and discordance between data sets within the major lineages. Coalescent-based analyses identify isolation, with little to no gene flow, as the primary driver of divergence between lineages. Recent isolation appears to have caused genetic bottlenecks in populations in the Sierra Madre Oriental and coastal mountain ranges of California, which may be targets for conservation concerns.
KW - Certhia
KW - coalescent analysis
KW - historical demography
KW - multilocus
KW - population bottleneck
KW - speciation
KW - species tree
UR - http://www.scopus.com/inward/record.url?scp=80053994851&partnerID=8YFLogxK
U2 - 10.1111/j.1365-294X.2011.05270.x
DO - 10.1111/j.1365-294X.2011.05270.x
M3 - Article
C2 - 21933295
AN - SCOPUS:80053994851
SN - 0962-1083
VL - 20
SP - 4371
EP - 4384
JO - Molecular Ecology
JF - Molecular Ecology
IS - 20
ER -