Wed, Aug 04, 2021:On Demand
Background/Question/Methods
The ability to accurately delimit species is of vital importance, particularly when dealing with taxa whose speciation is not immediately apparent. Phylogeographical analysis has emerged as a method that allows us to link micro and macroevolutionary processes in order to better understand speciation and divergence of sister taxa. Until recently, the Three-lined salamander (Eurycea guttolineata) was considered to be a subspecies of the Long-tailed Salamander (Eurycea longicauda). The most recent taxonomic analysis used both morphology and allozyme data to support the status of E. guttolineata as its own species. Our study aimed to produce a phylogenetic reconstruction of intraspecies variation across the range of E. guttolineata, with the intention of providing reliable data for future comparison studies of E. guttolineata and E. longicauda.
Results/Conclusions Using mtDNA analyses of the cytochrome-b (Cyt-b) gene and Bayesian inference models, we produced a phylogenetic reconstruction of E. guttolineata. Additionally, we were able to compare cyt-b haplotypes of E. guttolineata, and E. longicauda. Our analysis of E. guttolineata was characterized by a surprisingly low level of genetic diversity (~6% maximum divergence). This could potentially be due to a recent range expansion, or a large amount of gene flow between subpopulations throughout their range. Of utmost interest in our findings, was the identification of cyt-b haplotypes characteristic of E. guttolineata in southern populations of E. longicauda (within the species contact zone). Further investigation of the species contact zone is needed, and hybridization frequencies in this zone may provide insights on determining modes of speciation between these two species.
Results/Conclusions Using mtDNA analyses of the cytochrome-b (Cyt-b) gene and Bayesian inference models, we produced a phylogenetic reconstruction of E. guttolineata. Additionally, we were able to compare cyt-b haplotypes of E. guttolineata, and E. longicauda. Our analysis of E. guttolineata was characterized by a surprisingly low level of genetic diversity (~6% maximum divergence). This could potentially be due to a recent range expansion, or a large amount of gene flow between subpopulations throughout their range. Of utmost interest in our findings, was the identification of cyt-b haplotypes characteristic of E. guttolineata in southern populations of E. longicauda (within the species contact zone). Further investigation of the species contact zone is needed, and hybridization frequencies in this zone may provide insights on determining modes of speciation between these two species.