evolution

Paralogs

Seeing before LUCA. Most genes trace back to the Last Universal Common Ancestor (~4.2 billion years ago) and stop — a barrier beyond which we cannot see. But universal paralogs are different: rare gene families present in all organisms today that were duplicated BEFORE LUCA. Both copies were inherited by all descendants. These ancient pairs pierce through the barrier, letting us glimpse evolution that predates the origin of all modern life. All known universal paralogs involve protein synthesis or membrane transport — the oldest functions.