Rare traits persist in a population because predators detect common forms of prey more easily. Researchers writing in BMC Ecology found that birds will target salamanders that look like the majority – even reversing their behavior in response to alterations in the ratio of a distinguishing trait. 

The discovery of a gruesome feeding frenzy that played out 73 million years ago in northwestern Alberta may also lead to the discovery of new dinosaur species in northwestern Alberta.

University of Alberta student Tetsuto Miyashita and Frederico Fanti, a paleontology graduate student from Italy, made the discovery near Grande Prairie, 450 kilometres northwest of Edmonton. 

A new machine developed at North Carolina State University makes an animal heart pump much like a live heart after it has been removed from the animal's body, allowing researchers to expedite the development of new tools and techniques for heart surgery. The machine saves researchers time and money by allowing them to test and refine their technologies in a realistic surgical environment, without the cost and time associated with animal or clinical trials.

Acupuncture can help people with chronic low back pain feel less bothered by their symptoms and function better in their daily activities, according to the largest randomized trial of its kind, published in the May 11, 2009 Archives of Internal Medicine. But the SPINE (Stimulating Points to Investigate Needling Efficacy) trial raises questions about how the ancient practice actually works.

Aggressive, vengeful behavior of individuals in some South American groups has been considered the means for men to obtain more wives and more children, but an international team of anthropologists working in Ecuador among the Waorani show that sometimes the macho guy does not do better. 

The Waorani are rainforest manioc horticulturalists and foragers. When the first peaceful contact occurred in 1958, they numbered about 500 people living in an area the size of New Jersey between the Napo and Curaray rivers in the Amazon basin east of the Andes. Their abundant resources often attracted outsiders, who were promptly killed if found.

When it comes to immunity, men may not have been dealt an equal hand. The latest study by Dr. Maya Saleh, of the Research Institute of the McGill University Health Centre and McGill University, shows that women have a more powerful immune system than men. In fact, the production of estrogen by females could have a beneficial effect on the innate inflammatory response against bacterial pathogens. The results were published today in the Proceedings of the National Academy of Sciences.