Red Sea and the Atlantic Ocean, shared a common "Saharan-Sudanese culture", and drew their reinforcements from the same great source, even though, as time went by, they also absorbed a number of wanderers from the Near East". Biological anthropologists Shomarka Keita and A.J. Boyce have stated that the "Studies of crania from southern predynastic Egypt, from the formative period (4000-3100 B.C.), show them usually to be more similar to the crania of ancient Nubians, Kushites, Saharans, or modern groups from the Horn of Africa than to those of dynastic northern Egyptians or ancient or modern southern Europeans." Archaeological evidence has attested that population settlements occurred in Nubia as early as the Late Pleistocene era and from the 5th millennium BC onwards, whereas there is "no or scanty evidence" of human presence in the Egyptian Nile Valley during these periods, which may be due to problems in site preservation. Several scholars have argued that the African origins of the Egyptian civilisation derived from pastoral communities which emerged in both the Egyptian and Sudanese regions of the Nile Valley in the fifth millennium BCE. Deitrich Wildung (2018) examined Eastern Saharan pottery styles and Sudanese stone sculptures and suggested these artefacts were transmitted across the Nile Valley and influenced the pre-dynastic Egyptian culture in the Neolithic period. Pre-Kerma; A-Group (3500-3000 BC) Upper Nubia The poorly known "pre-Kerma" culture existed in Upper (Southern) Nubia on a stretch of fertile farmland just south of the Third Cataract. Lower Nubia Nubia has one of the oldest civilizations in the world. This history is often intertwined with Egypt to the north. Around 3500 BC, the second "Nubian" culture, termed the Early A-Group, arose in Lower (Northern) Nubia. They were sedentary agriculturalists, traded with the Egyptians, and exported gold. This trade is supported archaeologically by large amounts of Egyptian commodities deposited in the A-Group graves. The imports consisted of gold objects, copper tools, faience amulets and beads, seals, slate palettes, stone vessels, and a variety of pots. During this time, the Nubians began creating distinctive black topped, red pottery. The A-Group population have been described as ethnically “very similar” to the pre-dynastic Egyptians in physical characteristics. Around 3100 BC the A-group transitioned from the Early to Classical phases. "Arguably royal burials are known only at Qustul and possibly Sayala." During this period, the wealth of A-group kings rivaled Egyptian kings. Royal A-group graves contained gold and richly decorated