NeoDarwinism Depends
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| The Central Dogma of Molecular Biology states that the flow of information in cells is uni-directional starting with the DNA in the nucleus. From the DNA template containing the inherited information, an RNA strand is transcribed which is then transported to the ribosomes, the factory where proteins are manufactured from the information in the RNA strand. NeoDarwinism states that the only way for information to enter the cell is for there to be copying errors of the DNA. These copying errors, usually benign, sometimes fatal, but on rare occasion actually beneficial to the organisms, are supposed to confer on the individual an advantage to survive over the non-mutated brethren. Hence these DNA mutations are supposed to have propagated and displaced the normals, replacing one species with a more fit variation. But the dogma on which the theory rests has been abandoned by molecular biologists. In 1970 the protein reverse transcriptase was discovered which works contrary to expectation: It produces DNA from an RNA template! It is not true that new DNA is only added to the genome by gene duplication, with the duplicate copies free to mutate into useful new genes. It is not true that copying errors are the only means by which the genome is altered. Retrotransposons are DNA segments copied from RNA and are inserted into the genome. The huge repetitive segments of the DNA are thought to be the products of such insertions. These insertions are contrary to the “Weismann’s barrier” concept, where the germ line is supposed to not be influenced by the environment. Have these insertions influenced the course of evolution? Yes. |