Scientists zero in on little bug that was the ancestor of all living things

Thanks to the tools of modern genetics, scientists are working to identify a little bug that they believe was the ancestor of every creature alive today.
They call it LUCA — shorthand for the “last universal common ancestor” — and they think it inhabited the Earth 3 billion to 4 billion years ago.
LUCA consisted of only a single cell, like a bacterium, scientists say, but its descendants comprise modern humans, animals, plants, fungi and invisible microbes.
DuluthSuperior.com | 06/13/2005 | Scientists zero in on little bug that was the ancestor of all living things