The sixth mass extinction currently underway is due to a combination of climate change and destruction of natural habitats. Both crises are the result of our energy, industrial, and food production systems that have upended Nature. Biologist Michael Reed explains how the vitality of our planet depends on the health of ecosystems. Using migratory birds as an example, he describes the interdependence of different forms of life --- birds, animals, fish, insects, plants --and terrain. Dr. Reed also suggests why some species are better able to adapt to the climate and extinction crises than others. Worldwide action is urgently needed.

There is much interest today in the purpose of play. For humans, it is widely considered important for development, but for animals the role of play is less certain. In this fascinating description of the imaginative and varied play habits of many species of animals, David Toomey considers the purpose of this behavior, and he explains the major views on the subject.

"I saw it not only as a way to help me, but a way to provide hope for the thousands of people who need a transplant to survive,” said Richard Slayman.

Smithsonian Astrophysicist and Harvard Lecturer Matthew Holman discusses the search for undiscovered planets at the edge of the solar system.

Cement is the second most-consumed resource in the world—second only to water.

TRACTS, or the Translational Research Center for TBI and Stress Disorders, aims to develop effective treatments for veterans suffering from co-occurring disorders.

19th-century Bostonians realized that deforestation was changing the climate and pushed reforestation efforts visible today in parks like Middlesex Fells and the Blue Hills Reservation.

Karen Oates of Worcester Polytechnic Institute says integrating artificial intelligence and machine learning into public health—ethically—is key to innovation.

When asked how he deals with criticism, Loeb said that, "by now, my skin turned into titanium."

Alternating Hemiplegia of Childhood, or AHC, could see a new treatment thanks to a team of neurologists at Boston Children's Hospital.