The concept of presidential power is put to the test as President Trump asserts his authority, raising concerns about a potential constitutional crisis. Meanwhile, the story of William McKinley, the 25th president, is explored, and the reality TV show Survivor celebrates its 25th anniversary. In a fascinating example of environmental adaptation, the elks of the Rocky Mountains have developed a unique way of communicating with each other, using their vocalizations to overcome the challenges of their windy environment. [... more]