The antibacterial properties of nanosilver have led to a versatile application spectrum including medical purposes and personal care products. However, the increasing use of nanosilver has raised concerns about its environmental impacts. Long-term exposure studies with aquatic invertebrates are essential to assess possible adverse effects on aquatic ecosystems. In the present study, acute (48 h...

Climate change is expected to alter the range and abundance of many species by influencing habitat qualities. For species living in fragmented populations, not only the quality of the present patches but also access to new habitat patches may be affected. Here, we show that colonization in a metacommunity can be directly influenced by weather changes, and that these observed weather changes are...

Until recently, an enormous effort was needed to apply genomic tools to ecological investigations, especially when striving to uncover the functional mechanisms of phenotypic plasticity and the genetic basis of evolutionary adaptation within natural populations. This present study aimed to develop a genomic resource for an organism ideally suited for functional ecology and evolutionary research...

Recent characterization of the complete genomic sequences of multiple eukaryotes and prokaryotes is rapidly increasing our ability to understand how genome structure evolves and how gene expression and individual performance is modified in response to environmental challenges. These advances hold the promise of making a direct connection between the genome and the phenotype of organisms in popu...

Phenotypic plasticity is the ability of a genotype to produce more than one phenotype in order to match the environment. Recent theory proposes that the major axis of genetic variation in a phenotypically plastic population can align with the direction of selection. Therefore, theory predicts that plasticity directly aids adaptation by increasing genetic variation in the direction favoured by s...

The North American ecological species Daphniapulicaria and Daphniapulex are thought to have diverged from a common ancestor by adaptation to sympatric but ecologically distinct lake and pond habitats respectively. Based on mtDNA relationships, European D. pulicaria is considered a different species only distantly related to its North American counterpart, but both species share a lactate dehydr...

In the midwestern United States the Daphnia pulex complex consists of a mosaic of sexual and asexual populations, providing a useful model system for studying the evolutionary forces underlying the maintenance of sex. One asexual and two sexual populations were surveyed for genetic variation for isozymes, mitochondrial DNA, and life-history characters. While the sexual populations exhibited sub...

BACKGROUND Multiple transitions to obligate parthenogenesis have occurred in the Daphnia pulex complex in North America. These newly formed asexual lineages are differentially distributed being found predominantly at high latitudes. This conforms to the rule of geographical parthenogenesis postulating prevalence of asexuals at high latitudes and altitudes. While the reproductive mode of high-la...

Techniques were developed to study the effects of increased water temperature on certain zooplankters; specific studies were conducted on Daphnia pulex, an abundant and important zooplankter of the lower Columbia River. Study methods simulated prolonged exposure to constant high tempera· tures in thermal discharges and short exposures to increased temperatures in condensers of cooling systems. ...

Despite the great utility of mitochondrial DNA (mtDNA) sequence data in population genetics and phylogenetics, key parameters describing the process of mitochondrial mutation (e.g., the rate and spectrum of mutational change) are based on few direct estimates. Furthermore, the variation in the mtDNA mutation process within species or between lineages with contrasting reproductive strategies rem...