•    Published in Nature, the team led by Dr. Toni Gabaldón used the MareNostrum supercomputer to reconstruct the genetic origin of the last common ancestor of all eukaryotes—the cellular lineage to which animals, plants, fungi, and protists belong. •    The study challenges the idea that cellular complexity emerged from a single evolutionary encounter, pointing instead to a gradual process of interactions among different microorganisms that lasted for millions of years. •    The findings identify contributions from several bacteria, in addition to the one that gave rise to the mitochondria, and suggest that giant viruses may have acted as vehicles for genetic transfer.

Published in Nature, the team led by Dr. Toni Gabaldón used the MareNostrum supercomputer to reconstruct the genetic origin of the last common ancestor of all eukaryotes—the cellular lineage to which animals, plants, fungi, and protists belong.

The study challenges the idea that cellular complexity emerged from a single evolutionary encounter, pointing instead to a gradual process of interactions among different microorganisms that lasted for millions of years.

The findings, which culminate more than five years of computational work, identify contributions from several bacteria in addition to the one that gave rise to mitochondria, and suggest that giant viruses may have acted as vehicles for gene transfer.