Was the O Rh negative blood group produced as a consequence of extraterrestrial manipulation? If so, for what purpose?

This was a consequence of genetic manipulation by the extraterrestrials, not to alter the blood group per se, but doing a series of manipulations when they were exploring possibilities and were just behaving recklessly with callous disregard for consequences. This is the hallmark of their intrusions always. Humans are expendable. They don’t care what might go wrong as they will always learn something and the human beings themselves are expendable entirely and have no inherent value. They can always go back in time and do something to change the course of things if they choose. In most instances, they choose to let the damage continue as it increases their hold over things by weakening humanity.