My Picks From ScienceDaily

Prey Not Hard-wired To Fear Predators:

Are Asian elk hard-wired to fear the Siberian tigers who stalk them" When wolves disappear from the forest, are moose still afraid of them? No, according to a study by Wildlife Conservation Society scientist Dr. Joel Berger, who says that several large prey species, including moose, caribou and elk, only fear predators they regularly encounter. If you take away wolves, you take away fear. That is a critical piece of knowledge as biologists and public agencies increase efforts to re-introduce large carnivores to places where they have been exterminated.

Electric Fish Conduct Electric Duets In Aquatic Courtship:

Cornell researchers have discovered that in the battle of the sexes, African electric fish couples not only use specific electrical signals to court but also engage in a sort of dueling "electric duet." The study is the first to compare electrical and behavioral displays in breeding and nonbreeding Brienomyrus brachyistius, a type of mormyrid electric fish, which emit weak electric fields from a batterylike organ in their tails to sense their surroundings and communicate their species, sex and social status with other fish. It is also the first study to successfully sort signals in electric fish based on sex.

Invertebrate Immune Systems Are Anything But Simple:

A hundred years since Russian microbiologist Elie Metschnikow first discovered the invertebrate immune system, scientists are only just beginning to understand its complexity. Presenting their findings at a recent European Science Foundation (ESF) conference, scientists showed that invertebrates have evolved elaborate ways to fight disease.

Wild Sheep Descended From Single Pair Show Surprising Genetic Diversity:

Scientists at Université du Québec à Montréal have reconstructed the genetic history of a population of mouflons (wild sheep) descended from a single pair. The researchers demonstrated that the animals' genetic diversity increased over time, contrary to what the usual models predict. These results contradict the belief that a population descended from a small number of individuals will exhibit numerous deficiencies and reduced genetic diversity.

Placental Mammals Originated On Earth 65 Million Years Ago, Researchers Assert:

An early mammal fossil discovered in Mongolia led to researchers asserting that the origins of placental mammals, which include humans, can be dated to approximately 65 million years ago in the Northern Hemisphere. These findings will be published in the June 21 issue of Nature.

Brain's Voluntary Chain-of-command Ruled By Not One But Two Captains:

A probe of the upper echelons of the human brain's chain-of-command has found strong evidence that there are not one but two complementary commanders in charge of the brain, according to neuroscientists at Washington University School of Medicine in St. Louis.

It's as if Captains James T. Kirk and Jean-Luc Picard were both on the bridge and in command of the same starship Enterprise.

In reality, these two captains are networks of brain regions that do not consult each other but still work toward a common purpose -- control of voluntary, goal-oriented behavior. This includes a vast range of activities from reading a word to searching for a star to singing a song, but likely does not include involuntary behaviors such as control of the pulse rate or digestion.