Ever since the nineteenth century scientists have recognised that some regions contain more species than others, and that the tropics are richer in biodiversity than temperate regions. But why are there more species in the tropics? A new study publishing 28 January in the Open Access journal PLOS Biology scrutinizes most of the living mammalian species and reveals a two-fold mechanism; the rate at which mammals arose was higher in the tropics, and the rate at which they became extinct lower. They also propose that the tropics have been a continuous source of diversity that has permitted repeated colonization of the temperate regions.

Cambridge, Mass. – January 28, 2014 – Scientists at Harvard University and the Marine Biological Laboratory (MBL) hope new understanding of the natural nanoscale photonic device that enables a small marine animal to dynamically change its colors will inspire improved protective camouflage for soldiers on the battlefield.

The cuttlefish, known as the "chameleon of the sea," can rapidly alter both the color and pattern of its skin, helping it blend in with its surroundings and avoid predators. In a paper published January 29 in the Journal of the Royal Society Interface, the Harvard-MBL team reports new details on the sophisticated biomolecular nanophotonic system underlying the cuttlefish's color-changing ways.

Air pollution in China has exhibited noticeable changes over the past 30 years, shifting from point-source pollution (around factories and industrial plants) in the 1980s to urban pollution in the 1990s. Since the start of this century, air pollution has become increasingly regional and more complex. Recent research has indicated that the cooperative transition of SO2 and NOx into secondary aerosols (sulfate and nitrate) played a critical role in the haze pollution episode in China in January 2013.

Is your significant other fickle? Blame evolution, say psychologists in a new
Psychological Bulletin paper.

The authors analyzed dozens of published and unpublished studies to try and determine how women's preferences for mates change throughout the menstrual cycle. They suggest that ovulating women have evolved to prefer mates who display sexy traits – such as a masculine body type and facial features, dominant behavior and certain scents – but not traits typically desired in long-term mates.  

A hundred years ago, progressive efforts to bring about Utopia led to eugenics and social Darwinism, efforts to breed out undesirable traits by sterilizing people who had them. The concept was endorsed by luminaries such as the author H.G. Wells, economist John Maynard Keynes and Supreme Court Justice Oliver Wendell Holmes. Oh, and eventually the New York Times and Adolph Hitler.

Racism as a social and scientific concept recurs periodically and researchers need to be careful that the growth of genomics does not bring about another resurgence of scientific racism, according to anthropologist Nina Jablonski of Penn State.

Waste treatment facilities in the United States process more than 8,000,000 tons of biosolids - semi-solid sewage - about half of which is recycled into fertilizer and spread on crop land and which helps solve storage issues and produces revenue to support the treatment plants.

But what else is being spread in that sludge? As industry invents new materials and chemicals for modern products, many find their way to our skin and bloodstream and, subsequently, into our sinks and toilet bowls. More than 500 different organic chemicals have been identified in the biosolids used as fertilizer across the United States.