Johannes Bergsten

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Beetles represent almost one-fourth of all described species, and knowledge about their relationships and evolution adds to our understanding of biodiversity. We performed a comprehensive phylogenetic analysis of Coleoptera inferred from three genes and nearly 1900 species, representing more than 80% of the world's recognized beetle families. We defined(More)
Eight years after DNA barcoding was formally proposed on a large scale, CO1 sequences are rapidly accumulating from around the world. While studies to date have mostly targeted local or regional species assemblages, the recent launch of the global iBOL project (International Barcode of Life), highlights the need to understand the effects of geographical(More)
We introduce an open source software utility to extract the highly variable ITS1 and ITS2 subregions from fungal nuclear ITS sequences, the region of choice for environmental sampling and molecular identification of fungi. Inclusion of parts of the neighbouring, very conserved, ribosomal genes in the sequence identification process regularly leads to(More)
Evolutionary conflict between the sexes is predicted to lead to sexual arms races in which male adaptations for acquiring mates ("offense" traits) are met by female counteradaptations--for example, to reduce mating rate ("defense" traits). Such coevolutionary chases may be perpetual. However, we show here that the coevolutionary process may also lead to a(More)
Large-scale sequencing of short mtDNA fragments for biodiversity inventories ('DNA barcoding') indicates that sequence variation in animal mtDNA is highly structured and partitioned into discrete genetic clusters that correspond broadly to species-level entities. Here we explore how the migration rate, an important demographic parameter that is directly(More)
We review Bayesian approaches to model testing in general and to the assessment of topological hypotheses in particular. We show that the standard way of setting up Bayes factor tests of the monophyly of a group, or the placement of a sample sequence in a known reference tree, can be misleading. The reason for this is related to the well-known dependency of(More)
A correlation of species and genetic diversity has been proposed but not uniformly supported. Large-scale DNA barcoding provides qualitatively novel data to test for correlations across hierarchical levels (genes, genealogies and species), and may help to unveil the underlying processes. Here we analyse sequence variation in communities of aquatic beetles(More)
To understand the ecological and evolutionary consequences of species interactions in food webs necessitates that interactions are properly identified. Genetic analyses suggest that many supposedly generalist parasitoid species should rather be defined as multiple species with a more narrow diet, reducing the probability that such species may mediate(More)
In many groups of organisms, especially in the older literature, it has been common practice to recognize sympatrically occurring phenotypic variants of a species as "forms". However, what these forms really represent often remains unclear, especially in poorly studied groups. With new algorithms for DNA-based species delimitation, the status of forms can(More)
The African species of the genus Laccophilus Leach, 1815, are revised, on the basis of study of adult specimens. In all, 105 species are now recognized. A phenetic character-analysis was undertaken, which resulted in a split of the genus into 17 species groups. Diagnoses and a description of each species are given together with keys for identification of(More)