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Relationships between traits of organisms and the structure of their metacommunities have so far mainly been explored with meta-analyses. We compared metacommunities of a wide variety of aquatic organism groups (12 groups, ranging from bacteria to fish) in the same set of 99 ponds to minimise biases inherent to meta-analyses. In the category of passive(More)
Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one-fifth of the primary productivity on Earth. The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology. Here we(More)
There is a vivid debate on the relative importance of local and regional factors in shaping microbial communities, and on whether microbial organisms show a biogeographic signature in their distribution. Taking a metacommunity approach, spatial factors can become important either through dispersal limitation (compare large spatial scales) or mass effects(More)
Metacommunity studies on lake bacterioplankton indicate the importance of environmental factors in structuring communities. Yet most of these studies cover relatively small spatial scales. We assessed the relative importance of environmental and spatial factors in shaping bacterioplankton communities across a > 6000 km latitudinal range, studying 48 shallow(More)
The role of geographic isolation in marine microbial speciation is hotly debated because of the high dispersal potential and large population sizes of planktonic microorganisms and the apparent lack of strong dispersal barriers in the open sea. Here, we show that gene flow between distant populations of the globally distributed, bloom-forming diatom species(More)
The diatoms are the most speciose group of algae, having global ecological significance in the carbon and silicon cycles. They are almost unique among algae in being diplontic, and sexual reproduction is an obligate stage in the life cycle of most diatom species. It is unclear which are the principal factors that have fostered the evolutionary success of(More)
There is a long-standing belief that microbial organisms have unlimited dispersal capabilities, are therefore ubiquitous, and show weak or absent latitudinal diversity gradients. In contrast, using a global freshwater diatom data set, we show that latitudinal gradients in local and regional genus richness are present and highly asymmetric between both(More)
We characterized the bacterioplankton community and its seasonal dynamics in two neighbouring hypertrophic lakes by denaturing gradient gel electrophoresis (DGGE) analysis of short (193 bp) 16S ribosomal DNA polymerase chain reaction (PCR) products obtained with primers specific for the domain Bacteria. Lake Blankaart is turbid and has a high phytoplankton(More)
Diatoms are one of the most successful groups of unicellular eukaryotic algae. Successive endosymbiotic events contributed to their flexible metabolism, making them competitive in variable aquatic habitats. Although the recently sequenced genomes of the model diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana have provided the first insights(More)
Recent morphology-based studies indicate that freshwater diatom floras in the Antarctic comprise a significant share of endemics among a majority of apparently cosmopolitan species. Given the widespread (pseudo)cryptic species diversity in diatoms, we assessed the molecular divergence and temperature-dependent growth characteristics between Antarctic and(More)