Went down the rabbit hole on this. One equation from 1926 explains why your lungs and that tree look identical. A physiologist figured out that any system pushing fluid through branching tubes will naturally evolve toward the same shape. His rule is simple: when a tube splits into two smaller tubes, their sizes follow a precise ratio that wastes the least energy. Blood vessels follow it. Lung airways follow it. The water pipes inside trees follow it too. Your lungs branch 23 times between your windpipe and the tiny air sacs where oxygen enters your blood. Each split shrinks the tubes by the same ratio. After 23 rounds, a single 2cm-wide tube becomes 480 million air sacs with a combined surface area bigger than a studio apartment, all packed inside your chest. Trees do the same thing in reverse, branching outward to catch as much sunlight and CO2 as possible. Leonardo da Vinci noticed this 500 years before Murray. He wrote that all the branches of a tree at any height, when combined, are equal in thickness to the trunk below them. He used it to draw realistic trees. It took five more centuries for biologists to realize the same geometry applies inside your body. But the tweet oversimplifies the gas exchange part. Trees are not our primary oxygen source. NOAA estimates tiny ocean organisms called phytoplankton produce roughly half of Earth’s oxygen. One single species, Prochlorococcus (so small that 20,000 fit in a drop of seawater), produces about 20% of all the oxygen in our atmosphere. That’s more than every tropical rainforest combined. The Amazon’s net oxygen output is actually close to zero because the animals and microbes in the rainforest consume almost as much as the trees make. The real story behind that image: physics solved the same engineering problem billions of years apart, in completely unrelated organisms, and landed on the exact same answer.