The evolution of life has been a big enigma despite rapid advancements in the fields of biochemistry, astrobiology, and astrophysics in recent years. The answer to this puzzle has been as mind-boggling as the riddle relating to evolution of Universe itself. Despite the fact that panspermia has gained considerable support as a viable explanation for origin of life on the Earth and elsewhere in the Universe, the issue remains far from a tangible solution. This paper examines the various prevailing hypotheses regarding origin of life like abiogenesis, RNA(ribonucleic acid) world, iron-sulphur world, and panspermia; and concludes that delivery of life-bearing organic molecules by the comets and meteorites in the early epoch of the Earth alone possibly was not responsible for kick-starting the process of evolution of life on our planet. collapse ↑