Trump Picks Ex-Congressman to Manage U.S. Nuclear Arsenal

Brandon Williams served aboard a nuclear submarine and represented a New York congressional district for one term, but has said little about his experience in the management of atomic weapons.

How Lagging Vaccination Could Lead to a Polio Resurgence

In its original form, the virus survives in just two countries. But a type linked to an oral vaccine used in other nations has already turned up in the West.

This Tiny Fish’s Mistaken Identity Halted a Dam’s Construction

Scientists say the snail darter, whose endangered species status delayed the building of a dam in Tennessee in the 1970s, is a genetic match of a different fish.