Life as we know it descended from a single cell. What do we know about LUCA? Imagine the tree of life. The tip of every branch represents one species, whether you're talking about humans ...

whereas the oblong red shape denotes a typical archaeon with a cell wall. A: archaea; B: bacteria; E: eukaryote; LUCA: last universal common ancestor of cellular life-forms; LECA: last eukaryotic ...

However, until scientists determined the position of the LUCA (what evolutionary biologists ... are indeed fundamentally different at several cell biological levels, and not just in universal ...