decline in rainfall, and farming along the Nile now produced the vast majority of food, though contemporary paintings indicate that hunting was not entirely forgone. With increased food supplies, Egyptians adopted a much more sedentary lifestyle and cities grew as large as 5,000. It was in this time that Egyptian city dwellers stopped building with reeds and began mass-producing mud bricks, first found in the Amratian Period, to build their cities. Egyptian stone tools, while still in use, moved from bifacial construction to ripple-flaked construction. Copper was used for all kinds of tools, and the first copper weaponry appears here. Silver, gold, lapis, and faience were used ornamentally, and the grinding palettes used for eye-paint since the Badarian period began to be adorned with relief carvings. The first tombs in classic Egyptian style were also built, modeled after ordinary houses and sometimes composed of multiple rooms. Although further excavations in the Delta are needed, this style is generally believed to originate there and not in Upper Egypt. Although the Gerzean Culture is now clearly identified as being the continuation of the Amratian period, significant Mesopotamian influence worked its way into Egypt during the Gerzean, interpreted in previous years as evidence of a Mesopotamian ruling class, the so-called Dynastic Race, coming to power over Upper Egypt. This idea no longer attracts academic support. Distinctly foreign objects and art forms entered Egypt during this period, indicating contacts with several parts of Asia. Objects such as the Gebel el-Arak knife handle, which has patently Mesopotamian relief carvings on it, have been found in Egypt, and the silver which appears in this period can only have been obtained from Asia Minor. In addition, Egyptian objects are created which clearly mimic Mesopotamian forms, although not slavishly. Cylinder seals appear in Egypt, as well as recessed paneling architecture, the Egyptian reliefs on cosmetic palettes are clearly made in the same style as the contemporary Mesopotamian Uruk culture, and the ceremonial mace heads which turn up from the late Gerzean and early Semainean are crafted in the Mesopotamian "pear-shaped" style, instead of the Egyptian native style. The route of this trade is difficult to determine, but contact with Canaan does not predate the early dynastic, so it is usually assumed to have been conducted over water. During the time when the Dynastic Race Theory was still popular, it was theorized that Uruk sailors circumnavigated Arabia, but a