Mixing and Matching in the Evolution of Hemoglobin

Abstract

Hemoglobin, a multi-subunit protein used for oxygen transport to peripheral tissues in animals, has a rich evolutionary history that spans over 500 million years. Repeated use of pre-existing genes has generated novel functions, usually by means of gene duplication events that are followed by co-option. Consequently, the evolution of hemoglobin is a valuable model in understanding the conservative use of extant genetic resources to gradually build metabolic complexity.