Science. 2010 Dec 22. [Epub ahead of print] Revealing the Dark Matter of the Genome. Blaxter M. Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK. Abstract Animal embryos successfully transform the two-dimensional code of their genome into multidimensional organisms that are ready to meet the challenge of natural selection. In addition to the three dimensions of the body, animal genomes inform additional dimensions: of cells coordinating to form tissues, tissues functioning together as organs, and organs shaping the body's systems; and of individuals responding appropriately to the varied challenges of life and surviving to breed. Poisons in food are detoxified, pathogens are killed, parasites are eliminated, and predators avoided through the deft employment of responses encoded in the genome. It is not currently possible to compute an organism from its genome, performing the transformation so efficiently executed by embryos, but two articles in this issue, by Gerstein et al. and the modENCODE Consortium, bring this goal closer.