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) to them. Eventually, Superman tracks all the victims of the Vanishing to Metropia, an artificial paradise within the Phantom Zone, where he again encountered Equus, who has allied himself with General Zod, who is on a campaign to destroy Metropia. Equus, whose chestplate bears the Roman numeral "III", was the third version of a program to create super-soldiers. Equus, or "Vee Three" as he was designated, is said to be psychotic, due to the enlargement of the amygdalae to which the OMAC candidates were subjected. Equus III later appears in "Titans/Outsiders Secret Files 2005", stored alongside the Wildebeest, who had