Science

In polluted Pittsburgh, a new device from a local university helps residents assess indoor air. It's not the only monitor on the market — but is the only one available to borrow from a public library.

The ocean's tiniest inhabitants — including bacteria, plankton, krill — are food for most everything that swims or floats. Now, scientists have completed a count of this vast and diverse hidden world.

Genetically, at least, not that much has changed in the billion years since you two last shared a relative. Roughly half the 500 genes yeast need for life are interchangeable with the human versions.

New charities pop up all the time. But how do you know which ones work? Economists have come up with a strategy to figure it out. They've used it to tackle one of the biggest problems in the world.

How do you prove a rock was actively shaped and used as a tool more than 3 million years ago? Scientists found a kit of more than 140 artifacts in one spot and say the tools' crafters were pre-human.

What controls aging? Biochemist Cynthia Kenyon has found a genetic mutation that can more than double the lifespan of a tiny worm, which points to how we might one day significantly extend human life.

Medical ethicist Harvey Fineberg says "neo-evolution" is on the horizon. When it becomes easier to eliminate disease through gene therapy, will we change the trajectory of evolution?