Alligator eggs hatchingThe development of bone structures in alligator eggs raised under varying oxygen concentrations creates a link to fossil records of the evolution of vertebrates and prehistoric atmospheric oxygen concentrations, according to a paper to be presented at the Earth System Processes 2 meeting in Alberta, Canada.

Scientists have discovered that a group of important immune system cells has a surprising resemblance to cinematic British superspy James Bond: the cells receive a "license" that allows them to unleash their most potent attacks on enemies.

As anyone whose nerves have been jangled by a baby's howl or who have been riveted by the sight of an attractive person knows, nature has evolved sensory systems to be exquisitely tuned to relevant input. A major question in neurobiology is how neurons tune the strength of their interconnections to optimally respond to such inputs.

While Alfred Hitchcock's "The Birds" made many of us uneasy at the sight of amassing gulls years ago, today public health officials around the world are beginning to cast an equally uneasy eye toward migratory birds, especially in Alaska, following recent outbreaks of avian influenza in Southeast Asia and, last week, in Siberia.

Prehistoric big game hunters and not the last ice age are the likely culprits in the extinction of giant ground sloths and other North American great mammals such as mammoths, mastodons and saber-toothed tigers, says a University of Florida researcher.

Though quick to caution about the many things that could go wrong, researchers say that it may be possible to contain a Southeast Asian outbreak of avian influenza in humans, buying precious time for the production of a vaccine.