8 resultados para Christian Science
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Organisms provide some of the most sensitive indicators of climate change and evolutionary responses are becoming apparent in species with short generation times. Large datasets on genetic polymorphism that can provide an historical benchmark against which to test for recent evolutionary responses are very rare, but an exception is found in the brown-lipped banded snail (Cepaea nemoralis). This species is sensitive to its thermal environment and exhibits several polymorphisms of shell colour and banding pattern affecting shell albedo in the majority of populations within its native range in Europe. We tested for evolutionary changes in shell albedo that might have been driven by the warming of the climate in Europe over the last half century by compiling an historical dataset for 6,515 native populations of C. nemoralis and comparing this with new data on nearly 3,000 populations. The new data were sampled mainly in 2009 through the Evolution MegaLab, a citizen science project that engaged thousands of volunteers in 15 countries throughout Europe in the biggest such exercise ever undertaken. A known geographic cline in the frequency of the colour phenotype with the highest albedo (yellow) was shown to have persisted and a difference in colour frequency between woodland and more open habitats was confirmed, but there was no general increase in the frequency of yellow shells. This may have been because snails adapted to a warming climate through behavioural thermoregulation. By contrast, we detected an unexpected decrease in the frequency of Unbanded shells and an increase in the Mid-banded morph. Neither of these evolutionary changes appears to be a direct response to climate change, indicating that the influence of other selective agents, possibly related to changing predation pressure and habitat change with effects on micro-climate.
Resumo:
This entry discusses ‘immigration,’ which is the permanent movement of people across states, seen from the perspective of the receiving (rather than sending) states. The focus is on the relationship between immigration and states, a neglected topic in classic immigration research, but receiving more attention in recent scholarly literature. The entry discusses, in particular, some explanatory models of immigration policy and how the immigration experience has changed or reconfirmed the institution of citizenship.
Resumo:
Are there planets beyond our solar system? What may appear quite plausible now had only been a hypothesis until about twenty years ago. The search for exoplanets is driven by the interest in the “habitable” ones among them. Could such planets one day in the far future provide resources or even shelter for humankind? Will we find one day a habitable planet that is even inhabited? These kinds of imaginative speculations drive public interest in the subject. Imagining alien intelligent life in the universe is not at all new. When Ted Peters called for establishing the field of “astrotheology,” he was certainly thinking less of historical precedents than of something analogous to the emerging field of astrobiology. Will astrotheology result in the decentering of humanity in cosmic dimensions? One could also conclude that we are alone, at least for all practical purposes.