(AP Photo/Rodrigo Abd) Dr. Jorge Fusaro cools off by a stream during a rest from descending the Cerro Chañi, after completing his medical tour of the rural communities scattered across the mountain ...

Chañi is considered a sacred mountain by the indigenous Kolla people who live there. It has extreme temperatures, year-round snowy peaks, and is home to animals full of symbolism, like the puma ...

Chañi is considered a sacred mountain by the indigenous Kolla people who live there. It has extreme temperatures, year-round ...

“If we still lived in caves, we’d miss predators, for example — waking up during the night is how animals protect themselves ... up for insomnia,” says Kolla. “Also, using untested ...

From a pink dolphin slinking through the Amazon's waters to the sight of monarch butterflies filling the skies of Mexico, this year's best photos will take you on a journey across the planet.

This breakthrough reshapes our understanding of the genetic origins of stem cells, offering a new perspective on the evolutionary ties between animals and their ancient single-celled relatives.

Ms. Renkl is a contributing Opinion writer who covers flora, fauna, politics and culture in the American South. We were living in a cataclysmic age of mass extinction and climate instability even ...