Reproductive isolation from a cross between a horse and a donkey or between a mare and a donkey, respectively. These animals are nearly always sterile due to the difference in the number of chromosomes between the two parent species. Both horses and donkeys belong to the genus "Equus", but "Equus caballus" has 64 chromosomes, while "Equus asinus" only has 62. A cross will produce offspring (mule or hinny) with 63 chromosomes, that will not form pairs, which means that they do not divide in a balanced manner during meiosis. In the wild, the horses and donkeys ignore each other and do not
Equus (comics) foot long (with those corresponding to his thumbs considerably smaller), and while their composition is unknown, they are capable, given the physical strength Equus is capable of exerting with them, of piercing Superman's skin. Equus, the third version of the One Man Army Corps project, along with his predecessor, the second version, had their amygdalae enlarged as part of their genetic modifications, though this was scaled back for the subsequent versions, according to Mr. Orr, because this made the subjects psychotic. Specimens from the project that produced Equus were also said to have the wingbones of a fallen angel within