Every organism alive on Earth, from oak trees to octopuses to the bacteria in our gut, belongs to a single extended family. Genetic evidence points back to one ancestral cell, a last common forebear ...

Living organisms share an ancestor called the last universal common ancestor, or LUCA. LUCA is estimated to have lived approximately four billion years ago. All plants, animals, and microbes can trace ...

Here’s what you’ll learn when you read this story: Primitive single-celled organisms known as archaea have a survival mechanism that may be a legacy of the world’s earliest life-form. The last ...