In this issue:
"Rise of the Tyrannosaurs": The fearsome T. Rex turns out to be a late descendant in a family of surprisingly humble, mostly human-sized creatures.
"Lifting the Curse of Alzheimer’s": As the search for treatment turns to prevention, a couple of dozen Columbian families with a rare genetic form of the disease have emerged to play a key role.
"The Search for a New Machine": Computer chipmakers are betting billions on new technologies to improve performance.
"Waves of Destruction": The disappearing Arctic sea ice has given rise to towering waves that have far-flung effects on climate and ecology.