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) not being paid by him. Nox reminds him that Equus is there to aid him, but Equus brushes Nox aside, and attacks Superman. Superman is less forgiving in this rematch, using his X-ray and microscopic visions to learn much about Equus' enhancements, and physically disabling much of their exterior components. Equus escapes by activating the weapon, causing not only himself to vanish, but another 300,000 other people from across the planet. Superman subsequently learns that Equus has been working for a mysterious mustached man named Mr. Orr, who explains to Superman that Orr's employer's financed Nox's war, and loaned Equus