During evolution, genes can be created, get mutated or duplicated, and even can get lost. To investigate to what extent gene losses can contribute to different adaptations, scientists from the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden developed a computational method to identify gene losses and systematically searched the genomes of 62 mammals to analyze which genes are lost in which species. Their findings highlight a number of previously unknown gene losses that may have occurred as a consequence of a previous, existing adaptation, or – and more interesting – that may have played a direct role in the evolution of a new adaptation.