RESOLVING COMPLICATION. “In many lineages, the existence of WGD events, and the numbers of these events, remain unclear. Whether the vertebrate lineage had experienced two or three rounds of WGD was the subject of a long debate that was resolved only recently through a careful analysis of the synteny patterns of WGD paralogs.” (WGD = whole genome duplication).
http://www.pnas.org/content/107/1/472.full