If you have spent time with an infant, you might recognize the scene: A child is wailing, inconsolable, and you, the parent, have to go to the bathroom. Or eat. Or attend to a pot that’s boiling over.

Long before factories, mines, and cars filled the air with pollution, our distant ancestors were already living with a silent toxin: lead. A groundbreaking study reveals that hominids — from early ...

WASHINGTON — Humans are the only animal that lives in virtually every possible environment, from rainforests to deserts to tundra. This adaptability is a skill that long predates the modern age.