The llama and deer mouse both show evolutionary adaptations to hypoxic environments.  Studies document a leftward shift in the oxygen dissociation curves in these animals, indicating that these mammals have an increased affinity between blood and oxygen (Hall, 1936; Snyder, 1981).  As a result llamas and deer mice are capable of extracting a greater amount of oxygen form the air.  Primarily, these animals regulate this affinity by altering the DPG to hemoglobin ratios (Schmidt-Nielsen, 1997). 
Image courtesy of Washington Public Health Information Service.
Image courtesy of Brian Pinkerton at Mount Lehman Llamas. A decrease in DPG concentration will cause an increase in blood-oxygen affinity.  However, mammals living at high altitude must not completely eliminate DPG from the system otherwise oxygen would irreversibly bind to hemoglobin and no oxygen would diffuse into the tissues (Schmidt-Nielsen, 1997; Snyder et al., 1982).  

Main Page     Introduction     The Oxygen Dissociation Curve     Hypoxia     Llama      Deer Mice     Acknowledgements     Literature Cited     

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