Author(s):

Sowjanya BA, Narayana BD and Shreyas S

Abstract: Evolution is the change in the inherited characteristics of biological populations over successive generations. Charles Darwin was the first to formulate a scientific argument for the theory of evolution by means of natural selection. Available molecular techniques and rapidly expanding genome data from many organisms revealed great variation in the number of gene across the organisms. Several mechanisms are known to be involved in the origin of new genes such as gene duplication- duplication of chromosomal segments containing whole genes or gene fragments. Retro position-new gene duplicates created in new genomic positions by reverse transcription. Exon shuffling-exons from different genes brought together ectopically. Lateral gene transfer-process by which an organism incorporates genetic material from another organism without being a direct descendant of that itself. Gene fusion-fusion of two previously separate source genes into a single transcription unit. De-novo originationof new genes from previously non-coding sequences.And combined mechanisms-new genes can be created by the mechanisms discussed above, either individually or in combination. Among which transposable elements play a key role in the origin and evolution of both protein –coding genes and non-coding RNA sequences.

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