Essentials of Genetics 9th Edition by Michael Palladino William Klug, Michael Cummings, Charlotte Spencer

Exercise 12

Human adult hemoglobin is a tetramer containing two alpha (?) and two beta (?) polypeptide chains. The ? gene cluster on chromosome 16 and the ? gene cluster on chromosome 11 share amino acid similarities such that 61 of the amino acids of the ?-globin polypeptide (141 amino acids long) are shared in identical sequence with the ?-globin polypeptide (146 amino acids long). How might one explain the existence of two polypeptides with partially shared function and structure on two different chromosomes? Include in your answer a link to Ohno's hypothesis regarding the origin of new genes during evolution.