November-December 2018

Current Issue

November-December 2018

Volume: 106 Number: 6

Mountain lions disappeared from eastern and midwestern North America more than a century ago, as hunting and habitat loss diminished their numbers. Since then, they have been confined largely to the West, but they have continued to show up in rural legends and lore in the places that lost them. Many of these stories were tall tales or misidentifications, but there was rarely a way to know for sure. In the 1990s, the wild cats started showing up in places wildlife biologists did not expect them to be: on the prairies of the Midwest. The nonprofit Cougar Network was launched to document mountain lion presences, validating them with a photograph or video of the cat or its tracks or with DNA analysis of scat or hair. It was perfect timing: The cats were coming back east, at times trekking thousands of kilometers. In "America's Cat Is on the Comeback," wildlife biologist Michelle LaRue describes the incredible eastward journeys of this country's biggest cats. (Cover illustration by Eric Chow,

In This Issue

  • Art
  • Astronomy
  • Biology
  • Communications
  • Engineering
  • Environment
  • Ethics
  • Evolution
  • Mathematics
  • Physics
  • Policy
  • Sociology
  • Technology

Going Nowhere Fast

Ben Allanach


After the success of the Standard Model, experiments have stopped answering to grand theories. Has the quest for top-down unification of physics stalled?

Collecting Evolution

Matthew Joseph James

Biology Evolution

Expeditions that took animal specimens seem counter to modern conservation values, but their goal was to preserve species for scientific knowledge.

Scientists' Nightstand