Biogeography of the Southeastern United States: A Comparison of Salamander Phylogeographic Studies

Abstract

Most phylogeographic studies of species from the southeastern United States have shown a simple east-west division of mtDNA variation. However, a study of the salamander Ambystoma maculatum resulted in a more complex pattern that includes a close affinity between populations from the Central Highlands of Missouri and Arkansas and the Coastal Plain separated by a genetically distinct central group of populations. We test the generality of this observation by surveying mitochondrial DNA (mtDNA) variation in the closely related species A. talpoideum. An Ambystoma-specific intergenic spacer was amplified and sequenced. The 26 resulting haplotypes varied from 380 to 800 base pairs, and alignments, including the outgroup, required 101 insertions/deletions. Sequence divergence among haplotypes ranged from 0.001 to 0.758. Population subdivision was extensive (theta = 0.64). Phylogenetic analysis of A. talpoideum mtDNA sequence reveals a close relationship between the populations from the Central Highlands and the Coastal Plain. This result is similar to that obtained for A. maculatum, although the A. talpoideum clade is not as well differentiated from its sister clades. We discuss the differences and similarities between the two Ambystoma species and previous studies and call for increased focus on multiple species with similar ecologies as a way to detect subtle biogeographic events.

Cryptic lineage divergence in marine environments: genetic differentiation at multiple spatial and temporal scales in the widespread intertidal goby Gobiosoma bosc

“…Much more surprising is the deep phylogeographic break found on either side of the Apalachicola River estuary, with over 5% divergence among mtDNA lineages on either side. The Apalachicola River is a well-known barrier to gene flow for terrestrial organisms (Donovan, Semlitsch, & Routman, 2000;Pauly, Piskurek, & Shaffer, 2007) and freshwater fish (Bagley, Sandel, Travis, Lozano Vilano, & Johnson, 2013;Bermingham & Avise, 1986;Nedbal, Allard, & Honeycutt, 1994;Wooten & Lydeard, 1990), but this is to our knowledge the first reported case for a similar phylogeographic break in a marine fish, although at least one marine mollusk, the arrow squid (Loligo plei), was found to show a break there as well (Herke & Foltz, 2002).…”

Historical Isolation, Range Expansion, and Secondary Contact of Two Highly Divergent Mitochondrial Lineages in Spotted Salamanders (Ambystoma Maculatum)

“…Generally, genetic differentiation in Ambystoma salamanders is characterized by widely distributed and relatively uniform clades; sharp phylogeographic breaks, when present, are always associated with historical or current barriers to gene flow (e.g., Phillips 1994;Donovan et al 2000;Tallmon et al 2000;this study). The patterns of geographic genetic differentiation we uncovered in Ambystoma maculatum are qualitatively similar to patterns in other congeners, but not representative of all North American salamanders.…”

“…These two salamander radiations (Ambystomatidae and Plethodontidae), although widely overlapping in distribution (Duellman and Sweet 1999), differ dramatically in mating systems, life histories, dispersal potentials, and ecologies. These species-specific attributes have been traditionally viewed as idiosyncrasies that confound expected patterns of concordance, and this has prompted emphasis on comparative phylogeographic studies of species with similar characteristics (Joseph et al 1995;Schneider et al 1998;Donovan et al 2000). Many plethodontids are terrestrial breeders, mate in pairs or small groups (Verrell 1989), and exhibit species-specific courtship displays.…”

“…Most studies of genetic structure in eastern North America focus on taxa restricted to only a few biogeographical regions that were not directly affected by glaciers (e.g., Vogler and DeSalle 1993;Ellsworth et al 1994;Walker and Avise 1998;Donovan et al 2000). Fewer studies have examined terrestrial taxa currently occupying historically glaciated and unglaciated areas (e.g., Highton and Webster 1976;Hayes and Harrison 1992;Phillips 1994;Highton 1995;Shaffer and McKnight 1996;Arbogast 1999;Rodríguez-Robles and De Jesú s-Escobar 2000;Starkey et al 2003).…”

Population Structure of the Salamander Hynobius retardatus Inferred from a Partial Sequence of the Mitochondrial DNA Control Region

“…Salamanders have been used as subjects for biogeographical work (Templeton et al, 1995;Donovan et al, 2000;Steinfartz et al, 2000) as they generally show apparent genetic variation among populations with restricted gene flow, corresponding to their low level of dispersal ability (Donovan et al, 2000). In recent decades, intraspecific phylogeny and population genetics studies have been conducted using various molecular markers in several species of the Japanese salamander genus Hynobius, including H. tokyoensis (Matsui et al, , 2007, H. kimurae (Matsui et al, 2000), H. boulengeri , H. naevius (Tominaga et al, 2003), H. nebulosus (Yamane and Nishida, 2010), H. yatsui (Sakamoto et al, 2009), and H. retardatus (Matsui et al, 1992a).…”