Understanding genetic drift is crucial for a comprehensive understanding of biology, yet it is difficult to learn because it combines the conceptual challenges of both evolution and randomness. To help assess strategies for teaching genetic drift, we have developed and evaluated the Genetic Drift Inventory (GeDI), a concept inventory that measures upper-division students' understanding of this ...

The amount of genetic variability in species and populations has been mainly related to microevolutionary forces operating in natural populations and the influence of phylogenetic processes for the distribution of genetic variability has been neglected. To investigate how the current genetic variability distribution depends on the genetic variability of ancestral species, we simulated the evolu...

The rapid and accurate identification of Escherichia coli O157:H7 strains is central to reducing the impact of outbreaks. A real-time PCR-based approach to differentiating major outbreak lineages of O157 with novel single-nucleotide polymorphisms is described. The utility of this method is in detection of hypervirulent strains in cases of clinical disease.

BACKGROUND AND AIMS The Mediterranean Basin is one of the most important regions for the Earth's plant biodiversity; however, the scarcity of studies on fine scale patterns of genetic variation in this region is striking. Here, an assessment is made of the spatial genetic structure of all known locations of the three Sardinian endemic species of Aquilegia in order to determine the relative role...

Genetic drift, which is particularly effective within small populations, can shape the size and complexity of genomes by affecting the fixation of deleterious mutations. In Bacteria, assessing the contribution of genetic drift to genome evolution is problematic because the usual methods, based on intraspecific polymorphisms, can be thwarted by difficulties in delineating species' boundaries. Th...

One of the recurring arguments in evolutionary biology is whether evolution occurs principally through natural selection or through neutral processes such as genetic drift. A 60-year-long time series of changes in the genotype frequency of a colour polymorphism of the scarlet tiger moth, Callimorpha dominula, was used to compare the relative effects of genetic drift and variable natural selecti...