A collection of genes that are all products of gene duplication and have diverged from one another to a considerable degree. The repeated copies of an ancestral gene can follow three evolutionary pathways: (1) they can be inactivated by mutation, (2) they can acquire new functions, or (3) they can retain their original function. The globin superfamily of genes provides examples of genes that (1) mutated to pseudogenes (q.v.), (2) acquired new functions (the gene for myoglobin [q.v.] versus the alpha chain gene of hemoglobin), and (3) retained their original functions (the Gγ and Aγ genes). See hemoglobin genes.
Subjects: Genetics and Genomics.