Potential barriers to gene flow in the endangered European wildcat (Felis silvestris)
Hartmann, S.A. ; Steyer, K. ; Kraus, R.H.S. ; Segelbacher, G. ; Nowak, C. - \ 2013
Conservation Genetics 14 (2013)2. - ISSN 1566-0621 - p. 413 - 426.
maximum-likelihood-estimation - population-structure - computer-program - domestic cats - southern california - coalescent approach - landscape genetics - differentiation - hybridization - conservation
The European wildcat (Felis silvestris silvestris) is a focal species for conservation in many European countries. After a severe population decline during the 19th century, many populations became extinct or isolated. Within Germany, suitable wildcat habitat is assumed to be highly fragmented. We thus investigated fine-scale genetic structure of wildcat populations in Central Germany across two major potential barriers, the Rhine River with its valley and a major highway. We analyzed 260 hair and tissue samples collected between 2006 and 2011 in the Taunus and Hunsrück mountain ranges (3,500 km2 study area). We identified 188 individuals by genotyping 14 microsatellite loci, and found significant genetic substructure in the study area. Both the Rhine River and the highway were identified as significant barrier to gene flow. While the long-term effect of the river has led to stronger genetic differentiation in the river compared to the highway, estimates of current gene flow and relatedness across barriers indicated a similar or even stronger barrier effect to ongoing wildcat dispersal of the highway. Despite these barrier effects, we found evidence for the presence of recent migration across both the river and the highway. Our study thus suggests that although wildcats have the capability of dispersal across major anthropogenic and natural landscape barriers, these structures still lead to an effective isolation of populations as reflected by genetic analysis. The results strengthen the need for currently ongoing national strategies of wildcat conservation aiming for large scale habitat connectivity.
Global lack of flyway structure in a cosmopolitan bird revealed by a genome wide survey of single nucleotide polymorphisms
Kraus, R.H.S. ; Hooft, W.F. van; Megens, H.J.W.C. ; Tsvey, A. ; Fokin, S.Y. ; Ydenberg, R.C. ; Prins, H.H.T. - \ 2013
Molecular Ecology 22 (2013)1. - ISSN 0962-1083 - p. 41 - 55.
maximum-likelihood-estimation - mallard anas-platyrhynchos - influenza-a viruses - population-structure - mitochondrial-dna - phylogenetic networks - coalescent approach - genetic-structure - biased dispersal - white sharks
Knowledge about population structure and connectivity of waterfowl species, especially mallards (Anas platyrhynchos), is a priority because of recent outbreaks of avian influenza. Ringing studies that trace large-scale movement patterns have to date been unable to detect clearly delineated mallard populations. We employed 363 single nucleotide polymorphism markers in combination with population genetics and phylogeographical approaches to conduct a population genomic test of panmixia in 801 mallards from 45 locations worldwide. Basic population genetic and phylogenetic methods suggest no or very little population structure on continental scales. Nor could individual-based structuring algorithms discern geographical structuring. Model-based coalescent analyses for testing models of population structure pointed to strong genetic connectivity among the world's mallard population. These diverse approaches all support the conclusion that there is a lack of clear population structure, suggesting that the world's mallards, perhaps with minor exceptions, form a single large, mainly interbreeding population.