How did genome duplication in jawed vertebrates allow gene specialization?
I am currently reading from Chapter 15 in Principles of Life, 2nd Edition:>Many gene duplications affect only one or a few genes at a time, but in some cases entire genomes may be duplicated. When all the genes are duplicated, there are massive opportunities for new functions to evolve. That is exactly what seems to have happened during the course of vertebrate evolution. The genomes of the jawed vertebrates have four diploid sets of many major genes, which leads biologists to conclude that two genome-wide duplication events occurred in the ancestor of these species. These duplications allowed considerable specialization of individual vertebrate genes, many of which are now highly tissue-specific in their expression.My question is: how exactly does duplicating a genome enable specialization of genes? In other words, after vertebrates underwent genome duplication, how did one copy of the genome become "highly tissue-specific"?