Island footprint (IMAGE) University of Nebraska-Lincoln Caption Island-dwelling mammal species often expand or contract in size, becoming giant or dwarf versions of their mainland counterparts. A new Science study from a global team shows that those giants and dwarves have faced extreme risk of extinction — an existential threat exacerbated by the arrival of humans. Credit Scott Schrage | University of Nebraska–Lincoln Usage Restrictions Abide by CC BY-NC-ND License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.