Earth before life

BACKGROUND: A recent study argued, based on data on functional genome size of major phyla, that there is evidence life may have originated significantly prior to the formation of the Earth. RESULTS: Here a more refined regression analysis is performed in which 1) measurement error is systematically taken into account, and 2) interval estimates (e.g., confidence or prediction intervals) are produced. It is shown that such models for which the interval estimate for the time origin of the genome includes the age of the Earth are consistent with observed data. CONCLUSIONS: The appearance of life after the formation of the Earth is consistent with the data set under examination. REVIEWERS: This article was reviewed by Yuri Wolf, Peter Gogarten, and Christoph Adami.