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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

Right Whales Finally Coming Home Figure "CREDIT: MICHAËL CATANZARITI/WIKIMEDIA COMMONS" After more than 100 years, right whales have returned to their calving grounds in New Zealand, an international team of scientists reports. The 100-ton whales, known for their social frolicking and impressive acrobatic displays, were hunted to extinction in these same waters during the 19th and 20th centuries' era of industrial whaling. A small population managed to survive near remote, sub-Antarctic islands south of New Zealand. In recent years, a few dozen females found their way back to the same bays their ancestors used for bearing their young. Normally, such cultural knowledge is passed from mother to daughter, the researchers say. But the tradition had been lost, until these pioneering females began making the journey once again. Reporting in Marine Ecology Progress Series, the scientists-from Canada, the United States, Australia, and New Zealand-confirmed that some of the females had migrated from the southern islands to New Zealand by comparing the DNA in tissue samples collected from seven whales at both sites. Now that the tradition has been restored, scientists expect more whales to follow the pioneers.

"In some cases, cheaper types of fish were substituted for expensive species. In others, fish that consumers have been urged to avoid because stocks are depleted, putting the species or a fishery at risk, was identified as a type of fish that is not threatened. Although such mislabeling violates laws protecting consumers, it is hard to detect. Some of the findings present public health concerns. Thirteen types of fish, including tilapia and tilefish, were falsely identified as red snapper. Tilefish contains such high mercury levels that the federal Food and Drug Administration advises women who are pregnant or nursing and young children not to eat it."