A simple sample of the protective mucus layer that coats a frog's skin can now be analyzed to determine how susceptible the frog is to disease, thanks to a new technique. The findings could help scientists successfully reintroduce endangered amphibians into the wild by reducing the chance that the amphibians will be killed by diseases that may have played a role in the species' original declines.
The rate at which new species evolve is limited by competition for ecological niches. The study, which analyzes the evolutionary and genetic relationships between all 461 songbird species that live in the Himalayan mountains, suggests that as ecological niches within an environment are filled, the formation of new species slows or even stops.
Aging inevitably occurs both in humans and in other animals. However, life-span varies widely across species. Researchers have now found a possible general mechanism explaining differences in longevity. They investigated life history data of nearly 1400 bird species and found that avian life span varies considerably across the entire Earth, and that much of this variation can be explained by the species' body mass and clutch size and by the local diversity of predator species. The researchers were able to confirm a key prediction of the classical evolutionary theory of aging that had been proposed more than 50 years ago.