Ancestor of Animals Breathes Nitrogen

The earth is full of locales seemingly inhospitable to life. In areas like that deep beneath the ocean's mud floor, oxygen cannot penetrate. In such anoxic environments, the simple cellular precursors of all life--bacteria and archea--thrive, but the single-celled ancestors of more complex life-forms, known as eukaryotes, were thought to suffocate. Now new research has shown that at least one eukaryotic species--a shelled, amoebalike creature called a foraminifer--can prosper without oxygen by respiring nitrogen instead.