Molecular Evidence for the Early Colonization of Land by Fungi and Plants

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We thank M. Ray for assistance with data collection and L. E. Graham, J. F. Kasting, A. H. Knoll, L. R. Kump, and D. Schwartzman for comments or discussion. N.L.K. was supported by Women in Science and Engineering Research (NASA Space Grant to Penn State). Supported by grants from the NASA Astrobiology Institute (to S.B.H.).