Professor Nahum Sarna, formerly of Brandeis University, reported that modern scholars deduce from the Genesis listings of Jacob's sons the evolution of the league of Israelite tribes. These scholars deduce from the listing of Reuben, Simeon, Levi, and Judah as Leah tribes that they were politically related. As their tribal territories were not contiguous, their organizing principle could not have been geographical, and their association must therefore reflect a presettlement reality. These scholars conclude that the six Leah tribes must have originated as a separate fraternity in Mesopotamia that evolved in two distinct stages. The account of the birth of Jacob's sons in preserves the earliest traditions. The position of Judah as the fourth son reflects the situation prior to Judah's ascendancy, reflected in . The handmaid tribes had a subordinate status. And the tribe of Benjamin was the last to join the Israelite league and came into being in Canaan.