Targeting of nuclear-encoded proteins to different organelles such as mitochondria is a process that can result in the redeployment of proteins to new intracellular destinations during evolution With the sequencing of the Neandertal genome it has become possible to identify amino acid substitutions that occurred on the modern human lineage since its separation from the Neandertal lineage Here we analyze the function of two substitutions in mitochondrial targeting sequences that occurred and rose to high frequency recently during recent human evolution The ancestral and modern versions of the two targeting sequences do not differ in the efficiency with which they direct a protein to the mitochondria an observation compatible with the neutral theory of molecular evolution (C) 2010 Elsevier Inc All rights reserved