The New York Times > Science > Team Hopeful in Its Effort to Recreate Primal Life
... But the tree-constructing computer programs have been confounded by an awkward fact. Early in the history of life, genomes seem to have merged with one another. For instance, mitochondria, the tiny energy-producing organs of cells, were once free-living bacteria that were engulfed by the first eukaryotic cell. The programs are good at reconstructing standard evolutionary trees with a trunk and branch points, but cannot handle unusual events like merging two tree branches.
Dr. Lake's new program can apparently deconstruct the merger of two genomes. Applying it to the genomes of microbes from the three Woesian kingdoms, Dr. Lake and a colleague, Dr. Maria Rivera, found that eukaryotes were formed from a merger of an ancient photosynthetic bacterium with an archaeal cell.
That is presumably the same as the event in which mitochondria were captured, so Dr. Lake's conclusion is not surprising. But this is apparently the first time that the epochal merger has been reconstructed by genomic computation, a result that should make it much more amenable to further analysis.
Dr. Lake's finding also shows the three kingdoms of the Woesian view are not all of equal standing, as often supposed. By Dr. Lake's analysis, the bacteria and the archaea must have existed first, both presumably being descendants of the first cell, and the eukaryotes evolved later.
