The big news in science this week are tiny mechanical gears, found in nymph form of the the plant-hopping insect called issus. They help the insect achieve incredibly quick jumps (acceleration up to about 400g) with synchronization faster than even the speed of nerve impulses. The gears, which are lost when the insect undergoes its final molt to become an adult, are designed somewhat differently than the gears used in modern machines. I was reminded of a topic in evolutionary biology that considers the limits to what is “evolvable” in practice. We do not find “irreducible complexity” (by definition) in nature, but not all possible beneficial features are accessible to evolution. A classic example is the lack of “wheels” in living organisms, which has received quite a bit of thought (like here, here, and here). Before this discovery, I probably would have lumped mechanical gears in the same category, either as being too hard to evolve at all, or not worth the trouble. But apparently this was not the case!