Conditio Sine Qua Non for de Novo Emergence of New Genes and the Concept of Primordial Building Blocks
So long as a particular vital function is assigned to the single gene locus in the genome, all function-altering mutations are diligently eliminated by natural selection. Thus, the mechanism of gene duplication emerges as the prime means to create new genes with previously nonexistent functions (Ohno, 1970). Redundant copies of the existing gene created by this mechanism are largely ignored by natural selection, and while being ignored, they are free to accumulate function-altering mutations to emerge as new genes endowed with new functions. Indeed, the very> fact that nearly all the existing genes can be considered as members of different families by propinquity of their descents reveals the prime role this mechanism played in evolution; e.g., the serine protease family, β2-microglobulin family. Yet, this mechanism is very slow, inefficient and cumbersome as shall be pointed out shortly. Therefore, this mechanism is unfit to fulfill the organism’s need to cope with rapidly changing environments. In this paper, we shall point out that under certain conditions, new genes with new roles can emerge in a flash by two novel means.
KeywordsPolypeptide Chain Antifreeze Protein Balbiani Ring Alternative Reading Frame Redundant Copy
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