Luca, life’s precursor. Scientists speculate that Luca, a four-billion-year-old organism, may have originated in a hydrothermal vent. Credit: Volcanoes of the Deep Sea/Rutgers University

What do humans, insects, and algae all have in common? Very little, except for Luca.

Evolutionary biologists have revealed a detailed genetic profile of Luca, the Last Universal Common Ancestor of all living things. A new study, published Monday in the journal Nature Microbiology, provides insight into where and how this ancient precursor may have lived.

There are three basic types of living organisms on Earth: eukaryotes, bacteria, and archaea. Eukaryotes include all plants and animals. Bacteria and archaea are both single-celled, asexual organisms with no nucleus or organelles, but have distinct genetic and biochemical backgrounds

Researchers say that all three groups can be traced back to Luca, a single-celled organism that lived around 4 billion years ago. It is commonly thought that Luca’s descendants diverged into bacteria and archaea, and that eukaryotes emerged later. The ancestor’s physiology and habitat were mostly left to speculation, until now.

A group of evolutionary […]