Finding. New proteins come from nowhere or from almost-unrecognizable old genes. Tassios, Vakirlis, Rokas and colleagues count both across 332 yeasts: more than 5,000 de novo, more than 10,000 extreme-divergence. Predicted mitochondrial localization is 40% for de novo and 15% for divergent. Divergent proteins are longer and sloppier. Brand-new folds happen both ways, more often de novo. Sometimes an old fold is reinvented from noncoding DNA.
Score 79. Evolutionary mitochondrial bias. Medium confidence: prediction, possible helix bias.