About 500 million years ago, not a single creature had a skull. Over time, these bony plates evolved into the structural marvels that vertebrates—animals with spinal cords, aka you, me, and your pug, ...

Scientists are listening in on sperm whale conversations and studying Earth's strangest microbes to prepare humanity for first contact with extraterrestrial life.

Introduction: Nonnative species in the world / David Pimentel -- The impacts of alien plants in Australia / Richard H. Groves -- Environmental and economic costs of invertebrate invasions in Australia ...

A former CIA-linked physicist's comments about 'four alien species' have reignited UFO conspiracy theories online.