Human mediated introductions of non-native species can pose a major threat to global biodiversity on several accounts i.e. through competition, the introduction of novel pathogens, and genetic pollution. Where hybridization occurs between two closely related species the F1 offspring are usually phenotypically discernible whereas F2 hybrid, backcrossed or admixed individuals become more difficult to separate. At this point the utilization of molecular methods is required in conservation efforts to differentiate and manage populations. This study demonstrated how a possible threat of hybridization from an introduced non-native (T. carnifex) with a protected native newt species (T. cristatus) could be investigated with molecular tools, and examined the current extent of its genetic introgression over an 80 years period. The results confirmed that hybridization had taken place at the site of introduction (and continues to do so), and that historically limited local dispersal of both non-natives and/or hybrids had occurred sometime in the past. However, the data suggests that although dispersal of hybrids into a local satellite site may still be occuring, hybridization with native species appears limited.
ArntzenJ.W.Espregueira ThemudoG.WielstraB. (2007):
The phylogeny of crested newts (Trituruscristatus superspecies): nuclear and mitochondrial genetic characters suggest a hard polytomy, in line with paleogeography of the centre of origin.
Higher genetic diversity in introduced than in native populations of the mussel Mytella charruana: evidence of population admixture at introduction sites.
An integrative analysis of phylogenetic relationships among newts of the genus Triturus (family Salamandridae), using comparative biochemistry, cytogenetics and reproductive interactions.
J. Evol. Biol.3:
Hybridization and introgression between two species of crested newts (Triturus cristatus and T. carnifex) along contact zones in Germany and Austria: morphological and molecular data.
MeilinkW.R.M.ArntzenJ.W.van DelftJ.J.C.W.WielstraB. (2015):
Genetic pollution of a threatened native crested newt species through hybridization with an invasive congener in the Netherlands.
Hybridization between three crested newt species (Triturus cristatus superspercies) in the Czech Republic and Slovakia: comparison of nuclear markers and mitochondrial DNA.
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High genetic diversity but limited gene flow in Flemish populations of the crested newt, Triturus cristatus.
Belg. J. Zool.141 (1):
New polymorphic microsatellite loci for the Macedonian crested newt, Triturus macedonicus, and cross-priming testing in four other crested newt species.
Mol. Ecol. Resour.8:
A Bayesian approach on molecules and behavior: reconsidering phylogenetic and evolutionary patterns of the Salamandridae with emphasis on Triturus newts.
J. Exp. Zool. B: Mol. Dev. Evol.308B:
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TreerD.Van BocxlaerI.MatthijsS.Du FourD.JanssenswillenS.WillaertB.BossuytF. (2013):
Love is blind: indiscriminate female mating responses to male courtship pheromones in newts (Salamandridae).
PLoS ONE8 (2): e56538. DOI:10.1371/journal.pone.0056538.
The evolution of the adult body form of the crested newt (Triturus cristatus superspecies, Caudata, Salamandridae).
J. Zool. Syst. Evol. Res.49:
A revised taxonomy of crested newts in the Triturus karelinii group (Amphibia: Caudata: Salamandridae), with the description of a new species.