The author has proposed GADV hypothesis on the origin of life, suggesting that life emerged on the primitive Earth, not from RNA world but from [GADV]-protein world, which was formed by pseudo-replication of [GADV]-protein composed of Gly [G], Ala [A], Asp [D] and Val [V]! In parallel, the origins of gene, the genetic code and protein are comprehensively explained in the hypothesis, mainly based on protein 0th-order structure, or a specific amino acid composition, in which water-soluble globular protein can be produced at a high probability, even by random joining of amino acids.