Thermal environments can influence many fitness-related traits including life span. Here, we assess whether longevity in Drosophila melanogaster can experimentally evolve as a correlated response to cold-stress selection, and whether genotype-by-temperature and sex-by-temperature interactions are significant components of variation in life span. Three replicated S lines were cold-stress selecte...

Estimation methods for the Lévy density of a Lévy process are developed under mild qualitative assumptions. A classical model selection approach made up of two steps is studied. The first step consists in the selection of a good estimator, from an approximating (finite-dimensional) linear model S for the true Lévy density. The second is a data-driven selection of a linear model S, among a given...

Estimation methods for the Lévy density of a Lévy process are developed under mild qualitative assumptions. A classical model selection approach made up of two steps is studied. The first step consists in the selection of a good estimator, from an approximating (finite-dimensional) linear model S for the true Lévy density. The second is a data-driven selection of a linear model S, among a given...

Sliding-window analysis has widely been used to uncover synonymous (silent, d(S)) and nonsynonymous (replacement, d(N)) rate variation along the protein sequence and to detect regions of a protein under selective constraint (indicated by d(N)d(S)). The approach compares two or more protein-coding genes and plots estimates d(/\)(S) and d(/\)(N) fro...

A method is proposed for estimating the intensity of overdominant selection scaled by the effective population size, S = 2Ns, from allele frequencies. The method is based on the assumption that, with strong overdominant selection, allele frequencies are nearly at their deterministic equilibrium values and that, to a first approximation, deviations depend only on S. Simulations verify that reaso...

Estimates of the fraction of nucleotide substitutions driven by positive selection vary widely across different species. Accounting for different estimates of positive selection has been difficult, in part because selection on polymorphism within a species is known to obscure a signal of positive selection among species. While methods have been developed to control for the confounding effects o...

During protein synthesis, the ribosome catalyzes peptide-bond formation. Biochemical and structural studies revealed that conserved nucleotides in the peptidyl-transferase center (PTC) and its proximity may play a key role in peptide-bond formation; the exact mechanism involved remains unclear. To more precisely define the functional importance of the highly conserved residues, we used a system...