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 ...