Darwin thought our lungs evolved from the swim bladders of fish. It was more likely the other way around: early bony fish already breathed air with primitive lungs, as lungfish and bichirs still do today. In most modern fish, that organ was transformed into a gas-filled float. Your lungs and a goldfish's swim bladder share a common origin.
In 2022, a young tagged bar-tailed godwit flew from Alaska to Tasmania in about 11 days of nonstop flight, covering 13,560 km without eating, drinking or landing. Before departure, these birds pile on huge fat reserves and shrink their digestive organs, which are useless during the journey.
To escape rivals, a dung beetle rolls its ball of dung in a straight line. At night, it holds its course using the glowing band of the Milky Way. In a planetarium, researchers showed that beetles rolled straight under a starry sky but wandered aimlessly when the galaxy was switched off. It was the first animal known to navigate this way.