http://www.wired.com/wiredscience/2010/06/early-multicellularity/
“There is clearly a relationship between the concentration of oxygen and multicellularity,” said Abderrazak El Albani, a paleobiologist at France’s University of Poitiers. The fossils are described in the July 1 issue of Nature.
I wonder if the grouping was a defence against the oxygen levels.Mitochondria , a means , to remove toxic oxygen radicals , that as a by-product create a more stabilised easily excreted form of harmless unradicalized energy , ATP.
