Any multicellular animal, from a blue whale to a human being, poses a special challenge for evolution.
Most of the cells in its body will die without reproducing; only a privileged few will pass their genes to the next generation.
How could the extreme degree of cooperation required by multicellular existence actually evolve? Why aren't all creatures unicellular individualists determined to pass on their own genes?
"The leap from single-celled organisms to multicelled ones was a critical step in the history of life that paved the way for the world's plants and animals, including humans," says Sam Scheiner, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the research. "This study provides important clues that about the conditions necessary for that leap."