Saturday, June 05, 2010

Field Testing Sexual Selection in Crickets

Dance Like No One Is Watching, Sing Like No One Is Listening? in Science.
Genetic paternity testing and field observations of crickets challenge conventional wisdom about sex differences and fitness.
Freshwater Outburst from Lake Superior as a Trigger for the Cold Event 9300 Years Ago in Science.
Paleoclimate proxy records reveal a pervasive cooling event with a Northern Hemispheric extent ~9300 years ago. Coeval changes in the oceanic circulation of the North Atlantic imply freshwater forcing. However, the source, magnitude, and routing of meltwater have remained unknown. Located in central North America, Lake Superior is a key site for regulating the outflow of glacial meltwater to the oceans. Here, we show evidence for an ~45-meter rapid lake-level fall in this basin, centered on 9300 calibrated years before the present, due to the failure of a glacial drift dam on the southeast corner of the lake. We ascribe the widespread climate anomaly ~9300 years ago to this freshwater outburst delivered to the North Atlantic Ocean through the Lake Huron–North Bay–Ottawa River–St. Lawrence River valleys

The Lamb Shift

The Lamb Shift—Yesterday, Today, and Tomorrow in Science.
"Quantum field effects are magnified by collective interactions between many atoms."

The Local Void

Local difficulty for Big Bang in Nature.
The relativistic Big Bang theory of cosmic evolution gives a good description of our expanding Universe on the grand scale. But closer to home, where we can observe galactic properties in detail, its predictions go awry. For instance, some of the largest galaxies in our neighbourhood are found in less crowded regions, contrary to standard-model predictions. And the region known as the Local Void contains many fewer galaxies than expected. The observations of nearby galaxies are more understandable if it is assumed that matter forms more rapidly into galaxies and clusters than current theory allows. Jim Peebles and Adi Nusser outline recent efforts by cosmologists to adapt fundamental theory to let new physics operate on the scale of galaxies, yet preserve the properties of the present model on cosmological scales