Primordial eons ago E. asinus, the domestic donkey, and E. caballus, the domestic horse, went their separate genetic ways. Not long after H. sapien entered the evolutionary scene, humanity’s fascination with merging these equid species forever took hold. Today researchers are working to better understand both possible offspring from such a union: the mule and the hinny. In the U.S. the mule dominates this cross-bred world, while its reciprocal, the horse-sired hinny, is more common in South America and Europe. Recent findings comparing blood chemistry, for example, reveal how parental influence on hybrids can vary with respect to heart rate, respiration rate and  body temperature. Armed with this emerging insight, better care is more possible for these skilled farm and forest workers. (Source: Pilot Study, Amy McClean PhD, University of California, Davis)