The sudden appearance of large animal fossils more than 500 million years ago – a problem that perplexed even Charles Darwin and is commonly known as "Darwin’s Dilemma" – may be due to a huge increase of oxygen in the world’s oceans, says Queen’s paleontologist Guy Narbonne, an expert in the early evolution of animals and their ecosystems.

In the world of microbes, as in politics, some groups just can't seem to shake the label ''extremist.'' So it is with archaea (ar-KEY-uh), a collection of bacteria-like microorganisms whose unique genetics and chemical structure separate them from all other living things.

Ancient remains, once thought to be a key link in the evolution of mankind, have now been shown to be 400,000 years too young to be a part of man’s family tree.

Researchers at Université de Montréal, working with teams at Massachusetts General Hospital and Johns Hopkins University, have made a major breakthrough in understanding an essential aspect of the immune system. For the first time, using a systems biology approach, they have developed a model that facilitates the study of the function of the phagosome. The phagosome is the organelle responsible for the destruction of infectious pathogens that cause such diseases as tuberculosis and salmonellosis, as well as pathogens that could be used in bioterrorism. The results of their study were published this week in the prestigious journal Nature.

Working with a common form of brewer's yeast, University of Wisconsin-Madison researchers have uncovered novel functions of a key protein that allow it to act as a master regulatory switch -- a control that determines gene activity and that, when malfunctioning in humans, may contribute to serious neurological disorders.

Borrowing ideas from speech recognition research, Johns Hopkins computer scientists are building mathematical models to represent the safest and most effective ways to perform surgery, including tasks such as suturing, dissecting and joining tissue.

Researchers at the Salk Institute for Biological Studies in collaboration with scientists at the University of California, San Diego (UCSD) took a high resolution "action shot" of a protein switch that plays a crucial role in the development of the nervous system. Their findings, published in the Dec. 8 issue of the journal Molecular Cell, provide a template for the design of small molecule inhibitors to control that switch, a protein called Scp1, at will.

The discovery of a 100-million-year old bee embedded in amber -- perhaps the oldest bee ever found -- "pushes the bee fossil record back about 35 million years," according to Bryan Danforth, Cornell associate professor of entomology.

Researchers at Rensselaer Polytechnic Institute will continue to advance the frontiers of computational science with the help of IBM's Blue Gene supercomputer. Awarded under IBM's Shared University Research (SUR) program, this Blue Gene will complement the $100 million partnership between Rensselaer, IBM, and New York state to create one of the world's most powerful university-based supercomputing centers.

The study also provides new hope for controlling the devastating impact of Ebola on wild gorilla and chimpanzee populations. Since reports of ape die-offs first circulated widely in 2003, sceptics have doubted how large these die-offs were and whether Ebola was even the cause. The new study, led by Magdalena Bermejo of the University of Barcelona, allays these doubts because it was conducted in a closely monitored gorilla population where genetic tests confirmed Ebola as the cause of death. Bermejo and colleagues from the Max Planck Institute for Evolutionary Anthropology and Uppsala University first showed that 93% (221 of 238) individually known gorillas at the Lossi Sanctuary in northwest Congo were killed by Ebola during outbreaks in 2002 and 2003. They then used transect surveys to show that 95% gorilla mortality rates extended over a much larger area of several thousand square kilometres. Chimpanzees were also heavily affected, with a mortality rate of 77%.

Sildenafil and other "impotence drugs" that boost the production of a gassy chemical messenger to dilate blood vessels and produce an erection now also show promise in unmasking cancer cells so that the immune system can recognize and attack them, say scientists at the Johns Hopkins Kimmel Cancer Center.

Sea urchins are small and spiny, they have no eyes and they eat kelp and algae. Still, the sea creature’s genome is remarkably similar to humans’ and may hold the key to preventing and curing several human diseases, according to a University of Central Florida researcher and several colleagues.

For her research of life's first cells, Irene Chen, a regional winner from North America and the Grand Prize winner, today was named to receive the $25,000 GE & Science Prize for Young Life Scientists, supported by GE Healthcare and the journal Science, which is published by AAAS, the nonprofit society.

Scientists from Whitehead Institute and MIT have engineered yeast that can improve the speed and efficiency of ethanol production, a key component to making biofuels a significant part of the U.S. energy supply.

Malaria may be fueling the spread of HIV in areas of sub-Saharan Africa where there is a substantial overlap between the two diseases, while HIV may be playing a role in boosting adult malaria-infection rates in some parts of the region, according to a new study by researchers at Fred Hutchinson Cancer Research Center and the University of Washington.

It looks, contracts and responds almost like natural heart muscle – even though it was grown in the lab. And it brings scientists another step closer to the goal of creating replacement parts for damaged human hearts, or eventually growing an entirely new heart from just a spoonful of loose heart cells.