Habitats, stress, and evolutionary rates

Snowshoe hare pellet-decay rates and aging in different habitats

Snowshoe hare (Lepus americanus) pellet surveys are an efficient tool for monitoring population trends, but there is no standard methodology used to conduct surveys. To assist researchers in developing protocols, we evaluated pellet-decay rates and aging in 3 snowshoe hare habitat types in Alaska during the peak and decline of the hare population from 1999–2002. We found significant differences...

Metabolic Rates of Aquatic Arthropods from Different Habitats

Evolutionary rates and expression level in Chlamydomonas.

In many biological systems, especially bacteria and unicellular eukaryotes, rates of synonymous and nonsynonymous nucleotide divergence are negatively correlated with the level of gene expression, a phenomenon that has been attributed to natural selection. Surprisingly, this relationship has not been examined in many important groups, including the unicellular model organism Chlamydomonas reinh...

High mitogenomic evolutionary rates and time dependency.

Using entire modern and ancient mitochondrial genomes of Adélie penguins (Pygoscelis adeliae) that are up to 44000 years old, we show that the rates of evolution of the mitochondrial genome are two to six times greater than those estimated from phylogenetic comparisons. Although the rate of evolution at constrained sites, including nonsynonymous positions and RNAs, varies more than twofold with...

Variability of evolutionary rates of DNA.

A statistical analysis of DNA sequences from four nuclear loci and five mitochondrial loci from different orders of mammals is described. A major aim of the study is to describe the variation in the rate of molecular evolution of proteins and DNA. A measure of rate variability is the statistic R, the ratio of the variance in the number of substitutions to the mean number. For proteins, R is fou...