DNA is a biochemical that contains genetic information. And like all other cellular ingredients, it decays if cellular systems don't maintain it. Now, scientists are more confident about how fast it falls apart after a cell dies.

Salamanders are slick-skinned amphibians whose diets shift as they mature. Some live their entire lives in water, and others spend their adult lives on land. Those inhabiting water eat plankton when young and then various insects and other small arthropods called "clam shrimp" when older.

Nature, one of the premier science journals in the world today, recently published its editors' choice of science stories for 2011.¹