Scientists from Auburn University and international collaborators have uncovered the strongest protein-protein bond ever recorded in nature. Their discovery explains why Staphylococcus aureus, a leading cause of skin infections, clings so stubbornly to human skin — and points to new ways of fighting antibiotic-resistant bacteria.

Research led by University of Utah and Stanford analyzed thallium isotopes to show oxygen was slow to reach Earth’s ocean depths during the Paleozoic. O2 levels rose and fell at the ocean floor long after marine animals appeared and diversified half billion years ago, according to study of ancient marine sediments exposed by river cuts in Canada's Yukon.