Loess sediments and their soils cover around one-tenth of the earth. In Europe, loess is a powdery product of glaciations during the Ice Age. During those cold periods, this very fine, light material was swept from bare regions on the edges of the glaciers and deposited in regions with denser vegetation.

Loess consists largely of quartz grains and lime. The very fine grains ensure good aeration, water storage and mineral levels. This means that soils derived from loess are very fertile, like the black earth of the Börde plains, but are also particularly susceptible to erosion. It is therefore important to know where exactly these fertile soils so worthy of protection are to be found.

The November 2007 Special Issue of Frontiers in Ecology and the Environment focuses on paleoecology, which uses fossilized remains and soil and sediment cores to reconstruct past ecosystems.

Some scientists argue that the pre-Columbian Amazon was pristine, with indigenous people living in harmony with nature. Others suggest that the Amazon is a “manufactured” landscape, altered by and disturbed by human activities even before the arrival of Europeans. In “Amazonian exploitation revisited: ecological asymmetry and the policy pendulum,” Mark Bush (Florida Institute of Technology) and Miles Silman (Wake Forest University) discuss this debate.

Bush and Silman present paleodata from fossil pollen and charcoal in soil cores that support both perspectives.

The CO2 emissions of 50,000 power plants worldwide, the globe’s most concentrated source of greenhouse gases, have been compiled into a massive new database, called CARMA — Carbon Monitoring for Action.

The on-line database, compiled by the Center for Global Development (CGD), an independent policy and research organization that focuses on how the actions of the rich world shape the lives of poor people in developing countries, lays out exactly where the CO2 emitters are and how much of the greenhouse gas they are casting into the atmosphere.

The observation that males evolve more quickly than females has been around since 19th century biologist Charles Darwin noted the majesty of a peacock’s tail feather in comparison with the plainness of the peahen’s.

No matter the species, males apparently ramp up flashier features and more melodious warbles in an eternal competition to win the best mates, a concept known as sexual selection.

Why males are in evolutionary overdrive even though they have essentially the same genes as females has been a mystery, but an explanation by University of Florida Genetics Institute researchers in the Proceedings of the National Academy of Sciences this week may shed light on the subject.

A gene has been found in male cichlid fish that evolved to lure female fish so that male cichlids can deposit sperm in the females mouths. A study in BMC Biology reveals that the gene is associated with egg-like markings on the fins of cichlid fishes and uncovers the evolutionary history of these markings, which are central to the success of the fishes' exotic oral mating behavior.

Walter Salzburger, Ingo Braasch and Axel Meyer reared 19 cichlid species at Konstanz University in Germany and identified a gene involved in producing yellow pigment cells in oval spots on the fishes' fins.

Our brain is very good at picking up speech even in a noisy room, an adaptation essential for holding a conversation at a cocktail party, and now we are beginning to understand the neural interactions that underlie this ability.

An international research team reports in BMC Biology how investigations using neuroimaging have revealed that the brain's left hemisphere helps discern the signal from the noise.

In our daily lives, we are exposed to many different sounds from multiple sources at the same time, from traffic noise to background chatter. These noisy signals interact and compete with each other when they are being processed by the brain, a process called simultaneous masking.