The mystery of life’s beginnings has long captivated scientists. Central to that search is LUCA—the last universal common ancestor. LUCA sits at the root of the evolutionary tree, where two great ...

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 ...

Imagine the tree of life. The tip of every branch represents one species, whether you're talking about humans, E. coli, tardigrades, baker's yeast or giant kelp. If you follow any two branches back ...