Group items tagged

As the U.S. Food and Drug Administration (FDA) considers approving a genetically modified (GM) Atlantic salmon (Salmo salar), it faces fundamental questions of risk analysis and impact assessment. The GM salmon-whose genome contains an inserted growth gene from Pacific chinook salmon (Oncorhynchus tshawytscha) and a switch-on gene from ocean pout (Zoarces americanus)-would be the first transgenic animal approved for human consumption in the United States (1, 2). But the mechanism for its approval, FDA's new animal drug application (NADA) process (2), narrowly examines only the risks of each GM salmon compared with a non-GM salmon (2, 3). This approach fails to acknowledge that the new product's attributes may affect total production and consumption of salmon. This potentially excludes major human health and environmental impacts, both benefits and risks. Regulators need to consider the full scope of such impacts in risk analyses to avoid unintended consequences (4), yet FDA does not consider ancillary benefits and risks from salmon market expansion (2, 3), a result of what may be an overly narrow interpretation of statutes.

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

Life in Extreme Environments The Astrobiology Web offers this list of links about life in extreme environments. Subjects include general information, thermophilic life, deep ocean thermal vents, recommended books, and more.

"The Museum's science-rich website for curious minds ages seven and up makes complex scientific concepts accessible and fun through games, activiites, and stories. Kids can search Ology to learn more about their favorite science topics."