Nature’s Great Experiment with Gene Duplication during Evolution from Tunicate-like Creatures to Fish

Abstract

Of the various invertebrates which existed nearly 500 million years ago in Cambrian times, it was the simplest sessile form which gave rise to the first vertebrate through tunicate-like creatures. What was the genome of these uncommitted creatures like? I would venture a guess that the genome too had to be in an uncommitted state containing the bare essential number of structural genes, and having the least degree of redundancy. Only by starting in this way was it possible to utilize genetic redundancy subsequently created to write a new chapter in the evolution of metazoan animals.