A creative science reporter compares the “gears” of molecular motors in your muscle cells to those of high-performance cars.
A short but potent article in PhysOrg, “A nano-gear in a nano-motor inside you,” describes dynein—a molecular motor that transports cargo in cells and helps muscles work. In so doing, the reporter shows how nature outsmarted scientists who thought the motor was slow and inefficient. First, the build-up sets the stage in hunting terms:
To live is to move. You strike to swat that irritable mosquito, which skilfully evades the hand of death. How did that happen? Who moved your hand, and what saved the mosquito? Enter the Molecular Motors, nanoscale protein-machines in the muscles of your hand and wings of the mosquito. You need these motors to swat mosquitoes, blink your eyes, walk, eat, drink… just name it. Millions of motors tug as a team within your muscles, and you swat the mosquito. This is teamwork at its exquisite best.
Zooming into the cell, the article describes how a scientists used to wonder why “nature” made a “counter-intuitive choice” to use dynein, a rather sluggish motor, instead of the more powerful kinesin. By measuring the forces on dynein, a team at Tata Institute of Fundamental Research (TIFR), led by Dr. Roop Mallik, found the answer: dynein has gears. Mallik explained,
“Each dynein showed a special ability to shift gears, just like you shift gears in your car to go uphill. Therefore, each dynein in a team could speed up or slow down, depending how hard it was pulled back. This allowed the dyneins to bunch close together as they were pulling. The bunching helped dyneins to share their load equitably, and therefore work efficiently to generate large forces. Remarkably, motor-teams made up of another motor (called kinesin) which is much stronger than dynein, could not generate comparable forces. The reason? Well … you guessed it right. Kinesin does not have a gear!!”
The double exclamation points put the delight in finding the answer. “Because of this, dynein’s do much better at teamwork than other stronger motors that cannot change gears,” the article explained. And even though dynein gears are orders of magnitude smaller than those on a performance car, the principle is the same:
Taken together, these new studies show that Nature may have learnt how to use the gear in a motor much before we made our Ferrari’s and Lamborghini’s. But, what boggles the mind is that dynein’s gear works on a size scale that is ten-million times smaller than the Ferrari’s gear.
This led to a bit of debate in the comments about evolution vs. intelligent design, even though the article didn’t mention evolution.
Evolutionists try to explain this by saying that natural selection uses whatever works, even if the design is inelegant. But surely the key question is how did a molecular motor arise in the first place. It would seem a diversity of motors for different purposes is a good design. And if the reporter here thought of Ferrari’s and Lamborghini’s by comparison, how can the Darwinist invoke blind natural selection? From uniform experience, the only cause sufficient to arrange parts for gear-driven function is intelligence. Animals as diverse as flies and mammals share the same motors in their respective muscles. On the face of it, these considerations falsify neo-Darwinism, but Darwinians are clever. They say that the common ancestor invented the motors, then they stayed the same for millions of years along different evolutionary branches. They say, “Nature evolves to the point of ‘good enough’.” Such insufferable ingrates. Say that to a Ferrari designer.