And God Created ...

Flight Of The Fly

David Everson

In Exodus chapter eight, God brought upon the Egyptians "swarms of flies" to convince Pharaoh to release the children of Israel. The huge number of flies must have been an amazing thing to see. Yet, in the flight of a single fly, scientists discover amazing abilities built into the muscles of the fly by the Great Designer when He created it. Let us look at what they have discovered and see how we might understand better how our own bodies might work.

The ability of flying insects to beat their wings at amazing speeds to produce flight leaves engineers and scientists wondering how signals can be sent from the brain to the muscles fast enough to control flight. As Tom Irving of the Illinois Institute of Technology says, "For an insect, it is too difficult to have an electrical signal go from the brain to the muscle 200 times per second." This is the speed of the nerve signals if each beat of the wing of a fly were to be controlled separately. Instead, they have found in the muscles of the fly a mechanism that prevents the need for separate signals to control the muscle contractions. It is called "stretch activation" and involves one set of muscles automatically firing a contraction when its opposing set of muscles causes it to stretch. This contraction of one muscle after its opposite has contracted allows the muscles of the wings of the fly to move without a nerve signal from the brain. This is called an "internal feedback loop" and presents at least one problem. How does it turn off? Well, that is a good question and, as quoted by Live Science writer Michael Schirber in the Animal Domain section of the Live Science website, Tom Irvine says, "I'm not sure how it turns off."

When we are talking about these kinds of incredible speeds, it is truly amazing that insect flight happens at all! The common honeybee beats its wings at about 240 times per second; the fruit fly is a little slower at 200 times per second; but they cannot hold a candle to the male mosquito who beats its wings at 450 to 600 times per second. Still, that is almost a snails' pace when compared to the world's record holder, the "no-see-ums" or midges, which beat their hairy wings at more than 1,040 beats per second!

Besides the flight muscles which are housed in the thorax that produce lift, the insects also have at least 13 smaller muscles that are used to control all of the other aspects of flight. These muscles include those that control the basic principles of flight, like roll, pitch, and yaw. So, God has designed the flight ability of the insects with truly amazing complexity.

Scientists continue to study insect flight with ever-advancing technology, such as X-ray beams a million times more intense than those used for imaging the human body; but, at these intensities, it would only take a second to kill the insect they are studying. So, they have found that .03 millisecond exposures are necessary to get the pictures they need, but they need to get at least 150 of these short exposures. Creative scientists have learned how to tether flies in a way that they think they are flying when in reality they are just beating their wings and going nowhere. This allows a stationary target for the X-ray beams to get the pictures of the muscle fibers as they beat at these astronomical speeds.

Further study needs to be done in order to understand this simplest of God's creations, and, then, to see if we can learn how the human heart muscle beats, which happens in a similar "no signal" from the brain type of method. Let us praise the Creator each day as we watch his creations around us! -Rt. 1 Box 116A, Belington, WV 26250.


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