Even fish want to avoid carbon dioxide. Now we know that they can because of chemosensation and the Terminal Nerve.

None of us would get on a plane that had its parts changed in mid-air, says Eve Marder, who has spent her career probing a very specific cluster of crustacean nerve cells. Yet we are all walking around undergoing a constant turnover of cellular parts, and so are the lobsters and crabs Marder studies.

Black smokers are deep-sea hydrothermal vents found in the ocean. Now scientists believe that they may host electroecosystems in which the primary producers use electric currents as their energy source.