We’ve entered some profoundly unfamiliar planetary territory.

The UNLV School of Medicine is preparing to take the next critical step toward full accreditation and ultimately to expand its current class of 60 students per year to 120, then 180. This is in direct response to the needs of Southern Nevada.

As a one-time executive for Habitat for Humanity, Anthony Pipa saw how the organization’s homebuilding projects for struggling families brought together Americans from across the political spectrum in support of a worthwhile cause.

A growing number of U.S. children are being diagnosed with attention-deficit/hyperactivity disorder.

A growing number of U.S. children are being diagnosed with attention-deficit/hyperactivity disorder.

In one year’s time, the Trump administration went from acknowledging the struggles of intersex people to pretending they don’t exist.

Biologists now think there is a larger spectrum than just binary female and male

About 310 million years ago in what's now Arizona, a primitive creature trundled along on all fours through towering sand dunes that spilled into the sea. Normally, this creature's tracks would have vanished like other footfalls on a beach. But in a rare case, the tracks hardened into sandstone—preserving this flash of ancient behavior.

Some 310 million years ago, a reptile-like creature with an unusual gait roamed the sandy expanses of the Grand Canyon, leaving a trail of 28 footprints that can still be seen today. As Michael Greshko reports for National Geographic, these unusually well-preserved markers represent the national park’s oldest footfalls—and, if additional analysis links the early reptile to one that left a similar set of prints in Scotland roughly 299 million years ago, the tracks may even earn the distinction of being the oldest of their kind by more than 10 million years.