Fly trap explained, as reported in Nature, vol 433, p421, 21 Jan 2005 and Science News vol 167, 29 Jan 2005, p69. The Venus Flytrap is able to trap flies because it close its leaves in a second – a very rapid time frame for a plant movement. A group of scientists who shared an office at Cambridge University with a potted Venus Fly trap have investigated the mechanics of its leaf movements. Like many plant movements, it works by moving water into cells, but the rapid snap closure depends on the subtle double-curved geometry of the leaf. When an insect lands on the leaf it move hairs on the surface, which stimulates the plant to pump water into the outer surface cells, but not into the inner surface. The outer cells elongate and this builds up tension in the leaves. The curved shape of leaves means they initially resist this force so that tension builds up, and then after about one second makes them buckle into the closed shape. Charles Darwin described the Venus Fly Traps as one of the most wonderful plants in the world, and the authors of this recent study described the plants as “nature’s consummate hydraulic engineers.”

Editorial Comment: This is a good example of a system that requires forward planning. The system would not work unless the leaf had its subtle double curved geometry ahead of time. Neither would it work if the water movement didn’t occur in the right cells at the right time. To describe the plants as “nature’s consummate hydraulic engineers,” is to give credit to the creature instead of the Creator. (Ref. design, engineering, hydraulics)