Implications Of The Late Paleozoic Oxygen Pulse For Physiology And Evolution

The late Palaeozoic was marked by significant changes in atmospheric chemistry and biotic composition. Geochemical models suggest a marked increase and then decline of atmospheric oxygen and associated shifts in the concentration of carbon dioxide. Although the actual magnitude of these changes is uncertain, the pulse of oxygen concentration may have reached a maximum of 35% and then dropped to 15% (compared with the present 21%). This oxygen pulse may have influenced the evolution of major groups of organisms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62968/1/375117a0.pd