'Black Queen' sets forth the notion that eliminating a necessary function confers an evolutionary advantage-as long as your neighbors continue to do the work. The biologists published their results in a recent issue of the journal mBio, in a paper titled: 'The Black Queen Hypothesis: Evolution of Dependencies through Adaptive Gene Loss.' These non-symbiotic microbes, the researchers found, may be getting others to do the hard work of living for them. Scientists Jeffrey Morris and Richard Lenski of Michigan State University and the BEACON Center for the Study of Evolution in Action, and Erik Zinser of the University of Tennessee, Knoxville, knew that smaller genomes were the norm in symbiotic microbes-those that have reciprocally beneficial relationships-but wondered how non-symbionts got away with cutting out functions it appeared they needed. Their method lurks in the Black Queen Hypothesis, as it's called, after the Queen of Spades in the card game Hearts. Studies of common, microscopic ocean plankton named Prochlorococcus show that humans aren't the only ones who can play a mean game of cards. Sleight of hand is a trait that belongs mainly to humans.

Queen of spades play