From wild to domestic and in between: how domestication and feralization changed the morphology of rabbits

One of the world's most recognizable domestic animals is the rabbit, domesticated from the European rabbit. Domestication can drive morphospace expansion into novel phenotypes not observed in their wild counterparts; the consequences of feralization are less understood. Through these processes, we examine how humans have inadvertently driven great morphological change in this species. Characterizing skull morphological variation in a global sample of 912 wild, feral and domesticated specimens, we show that both domestication and feralization of rabbits have resulted in novel morphologies that leverage evolutionary patterns ubiquitous in the leporid clade: allometry and facial tilt are the principal axes of variation in rabbits as seen across species of Leporidae. However<i>,</i> rabbits diversified into regions of morphospace not explored by other species of their family. Although feralization of rabbits cannot be regarded as a 'reversal' to the wild form, we found they occupy an intermediate position, as well as their own allometric trajectory. Such insights from human-induced and environmentally driven morphological change of domestics and feral animals, respectively, reveal how novel morphologies can evolve at the macroevolutionary level. Future studies may elucidate the evolutionary, functional and developmental drivers and constraints of the cranial patterns observed in the rabbit.