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Winds of Change Jane Qiu Antarctica does not respond to global warming uniformly like a giant ice cube. Changing wind patterns are an unsung force shaping Antarctica's future. Retreating sea ice and stronger winds have caused seawater to mix more deeply, a process that churns sunlight-dependent phytoplankton into the ocean's depths. As a result, phytoplankton biomass has declined by 12% over the past 30 years. Higher on the food chain, that means fewer krill and fish larvae. These creatures are also getting hammered by the loss of sea ice, which hides them from predators. The complex interplay between air, sea, and ice has emerged as a central theme underlying climate change in Antarctica. Shifting wind patterns and corresponding ocean changes can explain climate responses across the continent.

Polar Bears Rooted in Ireland Polar bears and brown bears were separate species by 110,000 years ago. But new genetic studies of fossils and modern bears have revealed some hanky-panky 45,000 years ago, when polar bears interbred with now-extinct Irish brown bears. Hybridization with brown bears is a concern today because declining sea ice cover is forcing polar bears to extend their range and come into contact with brown bears. To understand the implications of hybridization, Beth Shapiro, an evolutionary biologist at Pennsylvania State University, University Park, and her colleagues compared mitochondrial DNA from 8000-year-old polar bear fossils, modern samples of polar bears, and ancient Irish bear fossils. Figure "CREDIT: FOTOSEARCH (2)" Modern polar bear mitochondrial DNA was most similar to that of the extinct Irish brown bear, whereas extinct polar bears had different mitochondria. Thus modern polar bears come from Europe, not islands between Alaska and Siberia, as had been previously thought, the researchers reported in Current Biology. The finding shows that interbreeding occurred during past episodes of climate change didn't destroy a species. "The big question for conservation of polar bears is if hybridization occurs rapidly and in combination with other stressors, will that hybridization have more of a negative effect now than it did in the past," says Andrew Whiteley, a geneticist at the University of Massachusetts, Amherst. http://scim.ag/_polarbears

"Spatial diversity gradients are a pervasive feature of life on Earth. We examined a global ocean circulation, biogeochemistry, and ecosystem model that indicated a decrease in phytoplankton diversity with increasing latitude, consistent with observations of many marine and terrestrial taxa. In the modeled subpolar oceans, seasonal variability of the environment led to competitive exclusion of phytoplankton with slower growth rates and lower diversity. The relatively weak seasonality of the stable subtropical and tropical oceans in the global model enabled long exclusion time scales and prolonged coexistence of multiple phytoplankton with comparable fitness. Superimposed on the decline in diversity seen from equator to pole were "hot spots" of enhanced diversity in some regions of energetic ocean circulation, which reflected lateral dispersal. "

Deceptive marketing may help. The iridescent material inside nautilus shells is sometimes machined into pleasing shapes and sold as "Osmeña pearl." (In the Philippines - home to much nautilus fishing - the Osmeña family is a political dynasty, and its name lends cachet.)