Gassing Up: Oxygen’s rise may have promoted complex life
By John Travis
Life’s long journey from single-celled organisms to multicellular plants and animals may have depended upon the increasing presence of oxygen in the atmosphere, a new study suggests.
S. Blair Hedges of Pennsylvania State University in State College and his colleagues reached this conclusion after correlating the number of cell types in dozens of classes of eukaryotes with the amount of oxygen in the atmosphere when those classes emerged in evolution. Eukaryotes include animals, plants, and other organisms that, unlike bacteria, store their DNA inside a cell nucleus.