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BACKGROUND AND AIMS Hybridization is an important evolutionary phenomenon, and therefore a detailed understanding of the dynamics of interspecific gene flow and resulting morphological and genetic patterns is of widespread interest. Here hybridization between the polyploids Cardamine pratensis and C. raphanifolia at four localities is explored. Using different types of data, the aim is to provi...

The majority of studies on leeches are related to: internal and external morphology. Fewer molecular research projects focus on molecular studies and karyology. The latter are needed to explain the evolutionary and systematic issues. Karyotypes for 22 species of Hirudinida have hitherto been determined, including: 8 species belonging to the Glossiphoniidae family, 3 species of Piscicolidae, 7 o...

A population of hybrid pocket gophers (Geomys bursarius x G. lutesccns) exists 1-2 km west of Oakdale, Antelope County, Nebraska, U.S.A. The hybrids occur in soil that has characteristics intermediate between that occupied by G. lutescens (sand) and by G. bursorim (silt loam); the vegetation associations on the different soils are Sandhills Prairie and Tall-grass Prairie, respectively, with mix...

We use an integrative taxonomic approach to revise the genus Anisopteromalus. In particular, we apply multivariate ratio analysis (MRA), a rather new statistical method based on principal component analysis (PCA) and linear discriminant analysis (LDA), to numerous body measurements and combine the data with those from our molecular analysis of Cytb and ITS2 genetic markers (on a subset of speci...

Although polyploidy plays a fundamental role in plant evolution, the elucidation of polyploid origins is fraught with methodological challenges. For example, allopolyploid species may confound phylogenetic reconstruction because commonly used methods are designed to trace divergent, rather than reticulate patterns. Recently developed techniques of phylogenetic network estimation allow for a mor...