The Complexity of the genome
About three years ago the human genome was mapped, and named The Book of Life. It appeared as if life started revealing some of its secrets. Soon diseases will be uniquely defined and in the future their faulty genes will be replaced with healthy ones. Investors rushed to reap the new discoveries only to find out that the Book fails to deliver the goods they hoped for. Actually the Book is not smarter than a telephone directory. Why then invest in a list of names?
True the Book is a blueprint of the organism. Each gene is located at the origin of an
assembly line of proteins. Unfortunately the mapping of gene to protein is
not one to one as molecular biologists claim. It is one to many
v. Streaming proteins
First of all there seems to be no correlation between the number of genes in the Book and the complexity of an organism. While the human genome consists of 25000 genes a worm has 19000. and a plant has 26000 genes. The complexity is generated all along the protein assembly line. Yet molecular biology still operates under the guidance of the Central Dogma of Molecular Biology. Information flows irreversibly from DNA to RNA to protein and the mapping from DNA to protein is one to one. Recent discoveries reveled that this mapping is actually one to many. With alternative splicing one gene may serve as template for many proteins. Recently discovered micro RNAs control the way messenger RNA copies the DNA gene, increasing the repertory of proteins which are coded from one gene even more. The mapping is one to exponentially many.
The reason for the excitement with the Book of Life was the naïve belief that it will inform us about diseases and their cure. Molecular biologists claim that diseases are gene aberrations. You take the genome of a sick person spread it on a DNA chip which is an array of gene products, and compare it with the DNA chip of a healthy one. With special dyes you make the deviant genes shine , and you can uniquely define a disease. To your dismay you find out that many genes lit up. You are dealing with a fairly large set of aberrant genes, and wonder which one should be replaced in order to cure the patient?
When the first genes were discovered, geneticists believed that the so called genetic diseases are caused by a change of a single gene. Soon they realized that most if not all diseases are caused by changes in many genes. Diseases are polygenic. How come that they still attempt to replace single genes? Since they regard the changes in other genes as negligible or irrelevant.
v. Iatrogenic medicine
v. A simple model of protein assembly
Molecular biology is dominated by the complexity demon:
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