New discoveries about reefs, pinniped evolution, and climate change.
Adults are taking stimulants like Ritalin and Adderall, normally used to treat serious medical conditions, to boost their concentration and job performance. Critics ask: Is it making Americans too dependent on their medicine cabinets?
Two new climate studies say that the US must cut carbon dioxide emissions by 90 to 95 percent to prevent the planet from becoming too warm.
Column: Advances in DNA research enhance basic concepts of evolution.