***MALARIA!!!*** ====== More people DIED from malaria on the swamps that Rome was built upon per month than new citizens were born or came to rome. The solution? Bring in population with a variety of GENETIC DEFENSES FROM MALARIA!. Not just sickle cell, but the various genes found only in Greece , Syria and Lenbanese peoples that resisted malaria. Also much of Rome were slaves waiting to become citizens. The problem with brown shitskin invaders into Rome, was gradual drop of IQ. Building on a swamp was the root cause though.... malaria. https://en.wikipedia.org/wiki/Human_genetic_resistance_to_malaria **LOOK AT MAP of malaria defense genes! Its the peoples that lived in Rome without dying immediately. Look at that wikipedia map** Map is "Old World distribution of hemoglobin-inherited disorders"