In the 1950s Anthony Allison, a British biochemist, observed that Africans who carry a single copy of the genetic mutation that causes sickle-cell anaemia are protected against malaria.
While a scientific breakthrough in its own right, it also brings the possibility of curing genetic diseases, growing new organs and even making a carbon copy of human beings one step closer.
First, when a new copy of copia inserts itself into a fly's genetic material, it may cause a deleterious mutation to a previously healthy gene (hence all the copia-related mutations detected by geneticists).