According to research, most if not all the people who have been abducted by aliens, share one thing in common. They all have RH negative blood. What this means is, the person possesses alien DNA. Further studies show, that RH negative blood types, do not possess the evolutionary gene derived from rhesus monkeys. Other blood types however seem to.
This is quite puzzling and makes one wonder…if we actually did come from monkeys, why would some people share the rhesus monkey gene while others simply do not?
One theory is, the RH negative blood somehow pertains to the ancient bloodline of the Nephilim. The Nephilim, are believed to be a parallel race of human species. Rh Negative blood is thought to be somewhat different than conventional DNA found in homo sapiens...
Source: http://www.freaklore.com/if-you-have-this-blood-type-you-might-be-part-alien