Regional Environmental Breadth Predicts Geographic Range and Longevity in Fossil Marine Genera

Geographic range is a good indicator of extinction susceptibility in fossil marine species and higher taxa. The widely-recognized positive correlation between geographic range and taxonomic duration is typically attributed to either accumulating geographic range with age or an extinction buffering effect, whereby cosmopolitan taxa persist longer because they are reintroduced by dispersal from remote source populations after local extinction. The former hypothesis predicts that all taxa within a region should have equal probabilities of extinction regardless of global distributions while the latter predicts that cosmopolitan genera will have greater survivorship within a region than endemics within the same region. Here we test the assumption that all taxa within a region have equal likelihoods of extinction.We use North American and European occurrences of marine genera from the Paleobiology Database and the areal extent of marine sedimentary cover in North America to show that endemic and cosmopolitan fossil marine genera have significantly different range-duration relationships and that broad geographic range and longevity are both predicted by regional environmental breadth. Specifically, genera that occur outside of the focal region are significantly longer lived and have larger geographic ranges and environmental breadths within the focal region than do their endemic counterparts, even after controlling for differences in sampling intensity. Analyses of the number of paleoenvironmental zones occupied by endemic and cosmopolitan genera suggest that the number of paleoenvironmental zones occupied is a key factor of geographic range that promotes genus survivorship.Wide environmental tolerances within a single region predict both broad geographic range and increased longevity in marine genera over evolutionary time. This result provides a specific driving mechanism for the spatial and temporal distributions of marine genera at regional and global scales and is consistent with the niche-breadth hypothesis operating on macroevolutionary timescales

Respiratory illness in children: Do deprived children have worse coughs?

Parents of a stratified random sample of 234 children from 21 general practices in North East England were interviewed at home. All these children had been reported in a postal questionnaire as having had a cough between six and ten weeks before the interview. Interviews covered social characteristics of the family, the severity of the child's cough and the reactions of the parents to hypothetical sets of symptoms. The parents of children in materially deprived circumstances appeared to report worse coughs than other parents. We confirmed this finding by constructing a scale of perceived cough severity. However, we found no evidence that the inequality was due to exaggeration of the severity of the cough by materially deprived parents. Our conclusion that materially deprived children suffer worse respiratory illness is the more important because previous evidence suggets that the after-effects persist into adulthood