Untitled

Abstract

Background: Models of the maintenance of sex predict that one reproductive strategy, sexual or parthenogenetic, should outcompete the other. Distribution patterns may reflect the outcome of this competition as well as the effect of chance and historical events. We review the distribution data of sexual and parthenogenetic biotypes of the planarian Schmidtea polychroa.

Diversification and biogeographic history of the Western Palearctic freshwater flatworm genusSchmidtea(Tricladida: Dugesiidae), with a redescription ofSchmidtea nova

“…Sequences of the mitochondrial gene Cox1 and the 28S ribosomal RNA gene (28S) of the different Schmidtea species were downloaded from GenBank. In the case of S. mediterranea and S. polychroa, those sequences were selected that capture the maximum genetic variability of the species, based on previous studies (L azaro et al, 2011;Pongratz et al, 2003), while for S. lugubris and S. nova, all available…”

“…The first Cox1 sequences of S. mediterranea and S. polychroa were obtained by Baguñ a, Carranza, Paps, Ruiz-Trillo, and Riutort (2001). Two years later, Cox1 of many populations of S. polychroa was sequenced for a phylogeographic study and two sequences of S. lugubris and S. nova were used as Translocation from one chromosome of the first pair to one chromosome of the third pair (Baguñ a et al, 1999) outgroup (Pongratz et al, 2003). Some years later, a Cox1 sequence of each Schmidtea species was included in a study on the molecular phylogeny of the triclads ( Alvarez-Presas, Baguñ a, & Riutort, 2008).…”

Combining Phylogeography with Distribution Modeling: Multiple Pleistocene Range Expansions in a Parthenogenetic Gecko from the Australian Arid Zone

“…This can allow the identification of parental taxa [13] as well as provide information on the number of clonal origins [14], the ages of clonal lineages [15], and the proportion of genetic variation in parthenogens due to post-formation mutation [16]. Recently developed molecular markers and analytical techniques have allowed for more detailed and informative genetic and phylogeographic comparisons between sexual and asexual taxa [7], [17]–[19]. In addition, combination of phylogeographic approaches with analyses of ecological tolerances and interactions can permit cross-validation of phylogeographic inferences [20] and lead to considerably more insight into the underlying processes that generate the observed patterns of geographic distributions, amounts and distributions of genetic variation, and ecological and climatic correlates [e.g.…”

Patterns of population structure in two closely related, partially sympatric caddisflies in Eastern Europe: historic introgression, limited dispersal, and cryptic diversity

“…Often, these patterns differ from those observed in similarly distributed terrestrial taxa. For example, many aquatic species have occupied numerous microrefugia (e.g., Weiss et al 2002, Pongratz et al 2003, Verovnik et al 2005. The high numbers of refugia observed in the Iberian (e.g., Gomez and Lunt 2007) and Balkan Peninsulas (e.g., Krystufek et al 2007) and in the Carpathian Mountains and basin (Botosaneanu 1973, 1975, Malicky 2006 indicate the importance of these regions as Pleistocene refugia and diversification centers.…”