Concerted evolution of human interferon alpha genes.

Multiple interferon (IFN) alpha genes characterize divergent animal species, yet human interferon alpha (HuIFN-alpha) genes are closely related in nucleotide sequence. Either the IFN-alpha genes derived from common ancestor sequences after divergence of these animals, or the HuIFN-alpha genes that have been studied underwent concerted evolution. Evidence suggesting that concerted evolution did occur to some unknown extent raises doubts about the important conclusion of recent divergence of the HuIFN-alpha gene family.