Current living zebras (top row), extinct quaggas (bottom row)DNA from museum samples of extinct animals is providing unexpected information on the extent and effect of the Ice Age as well as the path of species evolution, according to a report by scientists from Yale University, the Smithsonian Institute and the Max Planck Institute for Evolutionary Anthropology.

The biological clock controls the circadian rhythms of a wide range of physiological and behavioral processes, from fluctuating hormone levels to sleep-wake cycles and feeding patterns. While it's well known that circadian clock elements sense and respond to light cycles, much less is known about how daily temperature cycles affect the clock's timing mechanism in vertebrates. In the open-access journal PLoS Biology, Kajori Lahiri, Nicholas Foulkes, and their colleagues study temperature related responses at the genetic and molecular level in zebrafish.

Everyone knows morning people and late-night owls. The variation in individual circadian rhythms is an anecdotal as well as experimentally verified fact. But, until now, to systematically study circadian differences (and thereby hope to rout out the underlying genetic causes), scientists have had to rely on prolonged behavioural observation. To screen for and identify circadian rhythm variations in humans, the required period of lengthy observation is prohibitively costly and labor intensive.

There is little difference between the composition of the genetically produced potatoes known as fructan potatoes and that of conventionally bred varieties. They only differ in the new substances intentionally incorporated with gene technology. This conclusion has been reached by scientists at the Max Planck Institute of Molecular Plant Physiology and their colleagues from the University of Wales in a study published in the Proceedings of the National Academy of Sciences (PNAS, Online Early Edition, September 19). The scientists used a method developed at the Institute to identify substances in plants.

One teenager likes to snowboard off a cliff. Another prefers to read a book and wouldn't think of trading places. Why these differences exist is a mystery, but for the first time researchers have identified a possible genetic explanation behind risk-seeking behavior.

Vibrantly colored creatures from the depths of the South Pacific Ocean harbor toxins that potentially can act as powerful anti-cancer drugs, according to research findings from University of Wisconsin-Madison biochemists and their Italian colleagues.

Testing for drug resistance in HIV-infected patients at the time of HIV diagnosis is cost-effective and may increase patients' life expectancy, according to an article in the Nov. 1 issue of Clinical Infectious Diseases, now available online.

Junk food could be made healthier by adding an extract of an exotic type of seaweed, say British scientists.

Seven beauty queens from four continents today appealed to girls and young women to realize that modern ideas of "beauty" can damage their bones and lead to osteoporosis later in life.