Friday, 25 May, 2012

How do homing pigeons find their way on their amazing migrations? For a decade, scientists thought iron-bearing nerve cells in the beak can detect Earth’s magnetic field. But those iron granules are in immune cells. So how do the birds do it?

A crash course in “sink or swim” teaches computerized robots to adapt to changing circumstances. When taught by “directed evolution,” robots that started without legs learned to walk sooner than robots that started with legs! Can you explain?

Can pigeons learn an abstract mathematical rule? Apparently, according to a new study, which asked pigeons to place, five blue dots and eight green squares, in ascending order. Now we know birds and primates can both do this, but where and why did this ability originate?

In just a moment, our brains can go from calm, deliberate and focused, to alert, agitated and aroused. New neural networks get activated during the transition. Now a study of the fight-or flight-response fingers a common hormone in triggering the brainwide changes.

Plain-tailed wrens in the Andean cloud forest sing a complex, two-part song, where timing is everything. New research shows that both parties keep a memory of the full song in their brain, even though they only sing half of it.

athogens can change the behavior of their hosts — and now we see that a single viral gene forces a caterpillar to climb a tree before it dies. From that high vantage, the virus can infect more caterpillars. It’s nifty and thrifty, unless you’re a gypsy moth!

Found: The smallest farmers in the world! If you’re hungry, and moving to a land without food, the smart money says, “Take some seeds.” And that’s exactly what a common soil amoeba does: It totes along bacteria so it can eat them in its new home.

Three gross “biotherapies” are gaining medical attention, and two already have FDA approval as “medical devices” (?) ! Leeches can suck excess blood after surgery, and maggots remove dead tissue and kill bacteria in hard-to-heal wounds. Parasitic worms might fight ulcerative colitis — a widespread bowel disease. Maybe.

When chemicals in the water trigger the endocrine system, male fish can start looking and acting female. What happens once chemicals from plastics, drugs and our own endocrine system are flushed down the toilet? Can we prevent them from entering our streams and harming wildlife?

Changes in the junctions between nerve cells determine how well a bird will learn to sing. Regular change in these junctions helps the bird remember the song of its species, which it needs to learn to reproduce that song. Study could explain why older people have such trouble learning a new language.