The Protein Switch, Greatest Bodybuilder of them All
The muscle gives you motion and the force.
This invention comes
very early in evolution's course.
What great advantage the contracting protein gives.
The predator can pursue. The prey can take to flight.
If food is scarce, then just move to another site.
How far back to when the DNA codes the Actin and the Myosin?
Five hundred million years: that's how long its
In Cambrian seas, evolution experiments with how to paddle and to crawl.
Now see the "lowly" Jelly Fish, its graceful motion. Beware the Crab claw.
Do not let the leg inside the open Giant Clam, if you are SCUBA diver.
Go to the docks to buy some fish? Say hello to your remote ancestor.
The intrepid Dr. Shubin finds the
famous Tiktaalik in Devonian rocks on Ellesmere island,
Fish body, flat head, eyes on top, Humerus and radius, and you can see the hand.
Emerging from shallow seas to crawl upon the land.
Now there is a front, a back, a right and left.
Now there is the symmetry, A "bilaterian".
This model same, Fruit Fly and Eagle, Mouse and Elephant, Python and Homo sapiens.
The ancient DNA codes the Actin and the Myosin.
Other genes then code
the "Protein Switches",
These are the builders of the "Endless Forms Most Beautiful".
Think about the Latissimus of the Lion, Gluteus maximus of the Horse.
The Pectorals of an Eagle, all assembled in the embryo; from the Actin and
The same protein for all, but its the "Protein Switch" that orchestrates the shape and mass,
As different as the Lion and the Mouse. A Pelican and a Camel.
Surely the "Protein Switches" must be the greatest body builders of