The genetic turning point that made backbones possible

Scientists have uncovered a surprising genetic shift that may explain how animals with backbones—from fish and frogs to humans—became so complex. By comparing sea squirts, lampreys, and frogs, researchers found that key genes controlling cell communication began producing many more protein variations right at the moment vertebrates emerged. This genetic flexibility likely helped cells specialize in new ways, shaping the development of diverse tissues and organs.