The neural pathways that make up the brain arguably represents the most fiendishly complex electrical system in the cosmos, but what if not every brain is actually electrical? One pint-sized wasp might have a mechanical brain that runs like clockwork.
The greenhouse whitefly parasite measures in at about half a millimeter, but that tininess is nothing compared to that of its neurons. According to researchers at Germany's University of Göttingen, about a third of the axon fibers that connect together the wasp's neurons measure in at less than 0.1 micrometer in diamater. That's significant because, well, it's impossible for axons to be that thin.
The problem is that an axon that thin would be vulnerable to spontaneously firing, even when it's received no chemical signals. Such axons would continually relay inaccurate information to and from the brain, meaning the wasp wouldn't be able to trust the sensory data it received and likely unable to properly act on it anyway. The wasp should be effectively paralyzed by the neural noise inside its own brain.
New Scientist reports on a possible explanation for how the wasps manage to circumvent this rather elementary problem with their brains. If the electrical system can't be trusted in the wasps' axons, then it could substitute a mechanical system, in which axons would need to be physically touched in order to trigger the release of chemicals to the relevant neurons.
This mechanical approach would be a natural biological equivalent of a clockwork brain. It would greatly limit the flexibility of the wasp's mind and slow down reaction times considerably, but it's a simple enough creature that these problems would be relatively minor. Humans, on the other hand, would likely find such a clockwork mind unbearably slow-moving.
Via New Scientist. Top image of the clockwork robots from the Doctor Who episode "The Girl In The Fireplace."