Nimrod, the first GIANT whose name was recorded in the Bible, was biological son of Lucifer. He later killed his own mother's husband Cush, grand son of Noah and then married his own biological mother in INCEST.
That is how incest entered into mankind.
Nimrod son of Cush (Gen. 10:6-12; 1Chr. 1:8-10; Isa. 11:11), progenitor of various Ethiopian * and BLACK tribes that settled south of Egypt and also overran Arabia, Babylonia, and India. The folks from these nations prone to have incest. m&d also tends to habe incest because of their mixed DNA with Indians.
Blacks in general have no values as they are born of INCEST, they will do anything in real life. Nimrod and his mom and wife are being worshipped as god and goddesses in different religions.
This information is historical. scientific, genetical and Biblical.