There is now ample evidence of the ecological impacts of recent climate change, from polar terrestrial to tropical marine environments. The responses of both flora and fauna span an array of ecosystems and organizational hierarchies, from the species to the community levels. Despite continued uncertainty as to community and ecosystem trajectories under global change, our review exposes a coherent pattern of ecological change across systems. Although we are only at an early stage in the projected trends of global warming, ecological responses to recent climate change are already clearly visible.

No abstract

No abstract

Amphibians are good models for investigating the genetics of wild animal populations because they are: (1) widely distributed in most ecosystems; (2) easy to sample in breeding assemblages; (3) often philopatric to breeding sites, generating high levels of population genetic structure; (4) amenable to controlled crossings in the laboratory; and (5) of major conservation concern. Neutral genetic markers, mostly microsatellites, have been used successfully in studies of amphibian effective population sizes and structures, and in assessing the consequences of hybridisation. Phylogeography has provided important insights into population histories and the fates of introductions. Quantitative genetic methods have demonstrated adaptive variation in life history traits of importance to fitness and therefore to population viability. Heredity (2005) 95, 423-427.

The ability to maintain small populations in quasi-natural settings is an issue of considerable importance in biodiversity conservation. The genetic structure of urban common frog (Rana temporaria) populations was determined by allozyme electrophoresis and used to evaluate the effects of restricted intersite migration. Despite the lack of any absolute barrier to movement between ponds, substantial genetic differentiation was found between sites separated by an average of only 2.3 km. Genetic distances between these town ponds correlated positively with geographical distances and were almost twice as great as those found between rural sites separated by an average of 41 km. Measures of genetic diversity and fitness were always lowest in the town, where the degree of subpopulation differentiation (FST =0.388) was high. Population decline was not evident in the town, but molecular and fitness data indicated the presence of genetic drift and inbreeding depression. The long-term survival of artificially restricted populations, particularly of relatively sedentary species, may require molecular monitoring, if genetic diversity is not to be lost by chance when facets of the species niche prove to be poorly understood.