Rae Ellen Bichell

Animals, especially mammals, need oxygen to keep their bodies and brains humming along.

But leave it to the African naked mole-rat to buck that trend. The rodents are bizarre in just about every way. They're hairless, ground-dwelling and cold-blooded despite being mammals. Now, scientists report in the journal Science that the animals are capable of surviving oxygen deprivation.

Decades ago, scientists surgically attached pairs of rats to each other and noticed that old rats tended to live longer if they shared a bloodstream with young rats.

It was the beginning of a peculiar and ambitious scientific endeavor to understand how certain materials from young bodies, when transplanted into older ones, can sometimes improve or rejuvenate them.

Researchers have found that European eels can sense magnetic fields and may use this ability to navigate thousands of miles through the Atlantic Ocean.

Eels have always been mysterious animals. More than 2,000 years ago, Artistotle proposed that they were born spontaneously from mud.

"I think it's fascinating because as humans we've been pondering the life history of eels for a long time," says Lewis Naisbett-Jones, a graduate student in marine biology at the University of North Carolina, Chapel Hill.

Viruses are supposed to be tiny and simple — so tiny and simple that it's debatable whether they're even alive.

They're minimalist packets of genetic information, relying entirely on the cells the infect in order to survive and reproduce.

But in 2003, researchers identified a new kind of virus that that turned scientific understanding of viruses upside down, and tested the boundary of what can be considered life.

Exposure to lead as a child can affect an adult decades later, according to a study out Tuesday that suggests a link between early childhood lead exposure and a dip in a person's later cognitive ability and socioeconomic status.

Lead in the United States can come from lots of sources: old, peeling paint; contaminated soil; or water that's passed through lead pipes. Before policies were enacted to get rid of lead in gasoline, it could even come from particles in the fumes that leave car tailpipes.

A few months ago, at her office in Houston, Kate Rubins was feeling weird.

She was dizzy, she says — "staggering around like a 2-year-old who had just learned to walk." She was constantly looking at her desk to make sure the objects on top weren't floating away.

Rubins wasn't going nuts. She was just readjusting to Earth after living without gravity for four months, hundreds of miles above the planet's surface.

There is such a thing as a memory athlete. These are people who can memorize a truly insane amount of information really quickly, like the order of playing cards in a deck in under 20 seconds, or 200 new names and faces in a matter of minutes.

Neuroscientists writing Wednesday in the journal Neuron found these champs of memorization aren't that different from the rest of us.

When you step outside after a big rainstorm and take a deep whiff of that fresh, earthy smell, you're mostly smelling a chemical called geosmin.

It's a byproduct of bacteria and fungi. And something about rain lofts the chemical — and sometimes the organisms themselves — into the air, a process that not only helps release that earthy smell but may, in very rare conditions, spread diseases.

Somehow raindrops launch tiny living things off the ground.

It's not clear when or where life on this planet began, but scientists are working hard to find out.

Now, researchers writing in the journal Nature say they found fossils of what could be some of the earliest known creatures to grace the Earth, embedded in rocks that are at least 3.7 billion years old.

Initially, Clint Perry wanted to make a vending machine for bumblebees. He wanted to understand how they solve problems.

Perry, a cognitive biologist at Queen Mary University of London, is interested in testing the limits of animal intelligence.

"I want to know: How does the brain do stuff? How does it make decisions? How does it keep memory?" says Perry. And how big does a brain need to be in order to do all of those things?

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