- "To solve the mystery of how multicellular life persisted, scientists are suggesting what they call โratcheting [[mechanisms]].โ [[Ratchets]] are devices that permit [[motion]] in just one [[direction]]. By analogy, ratcheting mechanisms are traits that provide benefits in a [[group]] context but are detrimental to [[loners]], ultimately preventing a reversion to a single-celled state, said Libby and study co-author William Ratcliff at the Georgia Institute of Technology in Atlanta. In general, the more a trait makes cells in a group mutually reliant, the more it serves as a ratchet. For instance, groups of [[cells]] may divide [[labor]] so that some cells grow one vital molecule while other cells [[grow]] a different essential compound, so these cells do better together than apart, an idea supported by recent experiments with [[bacteria]]."