Why mantises don’t crash was explained in reports in Science Shots and Science Daily 5 March 2014, and Current Biology doi: 10.1016/j.cub.2015.01.054. Juvenile Praying Mantises do not have wings, so they can’t fly, but they can jump to reach targets like overhanging branches. However, small creatures such as insects can easily spin out of control when they jump, if there is any misalignment between the insect’s centre of mass and the force propelling it through the air.
A team of scientists in the UK have used high speed video to analyse the biomechanics of juvenile mantis jumps as the insects leapt from a platform to a thin black rod above and in front of the platform. They found the insects were deliberately generating spin and then distributing the angular forces in a controlled sequence. One of the researchers, Gregory Sutton of Bristol University, explained: “The mantis gives itself an amount of angular momentum at take-off and then distributes this momentum while in mid-air: a certain amount in the front leg at one point; a certain amount in the abdomen at another – which both stabilise the body and shifts its orientation, allowing it to reach the target at the right angle to grab on”.
Malcolm Burrows of Cambridge University commented: “We had assumed spin was bad, but we were wrong – juvenile mantises deliberately create spin and harness it in mid-air to rotate their bodies to land on a target. As far as we can tell, these insects are controlling every step of the jump. There is no uncontrolled step followed by compensation, which is what we initially thought”.
To test their theory that the insects were deliberately using abdominal movements to distribute the spin, the scientists glued the abdominal segments together. The mantises were still able to accurately reach the target but crash landed because they couldn’t correctly position their bodies for a controlled feet-first landing.
Sutton believes this research will help in the design of small robots. He commented: “For small robots, flying is energetically expensive, and walking is slow. Jumping makes sense – but controlling the spin in jumping robots is an almost intractable problem. The juvenile mantis is a natural example of a mechanical set-up that could solve this”. However, the scientists admit they will first need to understand how the insect’s brain controls the movements, which all happens “at lightning speed”.
Editorial Comment: These observations expose the foolishness of slow, gradual evolution by natural selection. Controlled jumping requires a flexible abdomen, quick acting muscles, and precision nervous system control. Until it had all of these, the mantis would not survive in the struggle for life. Half evolved mantises that crash landed would never develop into adults who could breed.
The fact that the mantis can jump without spinning out of control shows that controlled jumping is not an intractable problem – it just requires more cleverly designed scientific research to work it out. If anyone does solve the problem of jumping robots, it won’t be the mantises. It will be intelligent scientists who made the observations described in the experiments above, along with other equally intelligent scientists who work out how the movements are controlled. Yes, you’ve hit it on the head: Man’s brain is designed to think and create only because we didn’t evolve, but were made in God’s image. (Ref. Insects, aerobatics, design)
Evidence News vol.15, No. 3
11 March 2015
Creation Research Australia