English: A “living fossil”, the spotted gar diverged from the lineage of teleost fish (constituting half of all vertebrate species) before the teleost genome duplication. With its genome organized remarkably similar to that of a human, the gar provides an outgroup for connecting medical models of zebrafish and medaka to the human genome. Here, a gar larva 22 days old is stained for cartilage (Alcian blue) and bone (Alizarin red). See Catchen et al. (pp. 171–182). (Photo courtesy of Dr. Yi-lin Yan and Dr. Brian Eames).