Great white sharks in hot water, and more…

Some of the oceans biggest, most powerful predators, like certain sharks and tuna, are “mesothermic” or warm-bodied. Running hot allows them to rapidly convert their food to energy and heat, helping them swim faster and hunt in cold waters. But that advantage may become a disadvantage in a warming climate, meaning these fish need to find new ways of cooling off, or face a new threat to their survival.PLUS:Ancient Peruvians traded parrots across deserts and mountainsFrom the archive: David, Jay and Bob, and Quirks & Quarks' origin storySea cucumber 'zombie tissue' straddles the line between life and deathDream engineering may help you solve problems in your sleep