Ecology & Zoology

Ever since the relationship between land area and number of species crystallized into a mathematical power function, islands and island archipelagoes have been thought of as biological destinations where species from large continents arrive and, over time, evolve into new species in geographic seclusion. Since islands have many times fewer species than the continent, it seemed only logical that continents were rich sources from which islands drew only a small sample. Once isolated and with fewer species around, island organisms were thought to lose their competitive edge and so they hardly…

Tropical plants may be more adaptable than commonly thought to changing rainfall patterns expected to accompany a warming climate, new research shows. A University of Florida scientist and other researchers have found that plants in Hawaii have the ability to acclimate to big changes in rainfall in at least one important respect – how they get nutrients. The plants largely rely on one form of the vital nutrient nitrogen in moist areas. But in the still wetter terrain that characterizes some rainforests, they switch to another form of nitrogen that becomes more available in those conditions.…

A new, highly destructive strain of wheat stem rust is continuing to evolve and has the potential to devastate wheat production worldwide, say plant pathologists with The American Phytopathological Society (APS). Stem rust of wheat was responsible for massive epidemics on wheat during the early 20th Century in North America. In the mid-1950s, wheat breeders developed wheat that had genetic resistance to the disease, making it all but disappear. Despite this success, a new, virulent strain of wheat stem rust, Ug99, evolved in Uganda and has already spread into Kenya, Ethiopia and Yemen, with…

A new variety of corn developed and patented by Michigan State University scientists could turn corn leaves and stalks into products that are just as valuable as the golden kernels. Right now, most U.S. ethanol is made from corn kernels. This is because breaking down the cellulose in corn leaves and stalks into sugars that can be fermented into ethanol is difficult and expensive. "We've developed two generations of Spartan Corn," said Mariam Sticklen, MSU professor of crop and soil sciences. "Both corn varieties contain the enzymes necessary to break down cellulose and hemicellulose into…

Great Tits are, of course, songbirds - specifically Parus major. An international team of researchers have now found evidence for the existence of a "curiosity-gene" in our feathered friends. The gene (Drd4) carries the building instructions for a receptor in the brain, which forms the docking station for the neurotransmitter dopamine. Birds with a specific variant of this dopamine receptor D4 gene show a stronger exploratory behaviour than individuals with other variants. A hungry great tit is interested in the food on the table (left), but will remain hungry if he is too shy to approach…

Drought tolerance is a critical determinant of tropical plant distributions, researchers working at the Smithsonian Tropical Research Institute in Panama report in the May 3rd issue of Nature. In a novel coupling of experimental measurements and observed plant distributions across a tropical landscape, drought tolerance predicted plant distributions at both local and regional scales. This mechanism to explain a common observation will contribute significantly to models of land use and climate change. Tropical forest, often called rainforest, conjures up images of verdant, evergreen…

Even though they had the ability to evolve and survive for hundreds of millions of years - since before the time of the dinosaurs and through many climatic regimes - the massive, worldwide decline of amphibians can best be understood by their inability to keep pace with the current rate of global change, a new study suggests. The basic constraints of evolution and the inability of species to adapt quickly enough can explain most of the causes that are leading one species after another of amphibians into decline or outright extinction, say researchers from Oregon State University, in a study…

 What is it about keeping lab mice that continually seems to conjure images of World War II? Is it the obvious:that, in the case of lab mice, we are all Col. Klink, the hapless commandante of Stalag 17, doomed to dominance ohne respect? Or is it domething else in the increasingly murky relationship between the muridae and you and I? I was thinking about this the other evening on the way home from a family get together. As such events incline, it was pretty good, save for the continuing presence of my niece's fiance, a 250-poudner named Arthur. It's not the guy's weight that bothers…

There are many reasons why living in dense groups with others of your own kind is a good idea. Oftentimes, aggregations of a species serve as protection from predators and harsh environments or may be beneficial to future reproductive success. However, in the case of oyster larvae, the selection of a place to call home can be a life or death decision. A team of scientists has found that despite the risk of being eaten by cannibalistic adults, oyster larvae choose to settle in areas of high oyster concentrations to take advantage of future benefits of increased reproductive capacity when they…

Some plants need a partner to reproduce. Pollen from one plant pollinates the stigma of another, and a seed is formed. But other plants can self-pollinate, a handy survival mechanism for a lonely plant. The ability to self-pollinate turns up in cultivated tomatoes and canola, among other important crops, and sometimes it can be a nuisance for plant breeders and seed producers who want to develop highly desirable hybrid varieties and produce hybrid seed on a commercial scale. To get hybrid seed, they plant two different varieties in the same field to allow them to cross-pollinate. But if one…