Group items matching

in title, tags, annotations or url

Warming and Melting Mass loss from the ice sheets of Greenland and Antarctica account for a large fraction of global sea-level rise. Part of this loss is because of the effects of warmer air temperatures, and another because of the rising ocean temperatures to which they are being exposed. Joughin et al. (p. 1172) review how ocean-ice interactions are impacting ice sheets and discuss the possible ways that exposure of floating ice shelves and grounded ice margins are subject to the influences of warming ocean currents. Estimates of the mass balance of the ice sheets of Greenland and Antarctica have differed greatly-in some cases, not even agreeing about whether there is a net loss or a net gain-making it more difficult to project accurately future sea-level change. Shepherd et al. (p. 1183) combined data sets produced by satellite altimetry, interferometry, and gravimetry to construct a more robust ice-sheet mass balance for the period between 1992 and 2011. All major regions of the two ice sheets appear to be losing mass, except for East Antarctica. All told, mass loss from the polar ice sheets is contributing about 0.6 millimeters per year (roughly 20% of the total) to the current rate of global sea-level rise.

Summary: Assess coral bleaching using water temperature data from the NOAA National Data Buoy Center. Objectives * Describe the relationship between corals and zooxanthellae. * Identify stresses to corals. * Explain coral bleaching and the processes that cause coral bleaching. * Examine water temperature data and compare to levels known to induce coral bleaching. * Predict the effects of prolonged, increased temperaturs on coral reefs. Introduction The magnificent beauty of a coral reef is a true masterpiece of Mother Nature. A reef is a sculpture of living organisms, varied in color, texture, shape, and size. The creation of these works of art takes many, many years (some reefs are thousands of years old), and they don't exist solely for show. Reefs are building blocks for rich communities, providing habitat for a myriad of organisms, and they are some of the most diverse ecosystems on the planet. In addition, they support fishing grounds, attract tourists, and protect shorelines from waves and storms. "

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.

Evolution Two Critics Without a Clue What Darwin Got Wrong by Jerry Fodor and Massimo Piattelli-Palmarini Farrar, Straus and Giroux, New York, 2010. 286 pp. $26. ISBN 9780374288792. Profile, London. 280 pp. £20. ISBN 9781846682193. 1. Douglas J. Futuyma + Author Affiliations 1. The reviewer is at the Department of Ecology and Evolution, Stony Brook University, 650 Life Sciences Building, Stony Brook, NY 11794-5245, USA. 1. E-mail: futuyma@life.bio.sunysb.edu Summary Objecting on both philosophical and empirical grounds, Fodor and Piattelli-Palmarini reject natural selection as the mechanism of adaptive evolution.