Sumer
Sumer () is the earliest known civilization in the historical region of southern Mesopotamia, modern-day southern Iraq, during the Chalcolithic and Early Bronze ages, and one of the first civilizations in the world along with Ancient Egypt and the Indus Valley. Living along the valleys of the Tigris and Euphrates, Sumerian farmers were able to grow an abundance of grain and other crops, the surplus of which enabled them to settle in one place. Prehistoric proto-writing dates back before 3000 BC. The earliest texts, from c. 3300 BC, come from the cities of Uruk and Jemdet Nasr; early cuneiform script emerged around 3000 BC.
Afroasiatic languages
The earliest written evidence of an Afroasiatic language is an Ancient Egyptian inscription dated to c. 3400 BC (5,400 years ago). Symbols on Gerzean (Naqada II) pottery resembling Egyptian hieroglyphs date back to c. 4000 BC, suggesting an earlier possible dating. This gives us a minimum date for the age of Afroasiatic. However, Ancient Egyptian is highly divergent from Proto-Afroasiatic (Trombetti 1905: 1–2), and considerable time must have elapsed in between them. Estimates of the date at which the Proto-Afroasiatic language was spoken vary widely. They fall within a range between approximately 7,500 BC (9,500 years ago), and approximately 16,000 BC (18,000 years ago). According to Igor M. Diakonoff (1988: 33n), Proto-Afroasiatic was spoken c. 10,000 BC. Christopher Ehret (2002: 35–36) asserts that Proto-Afroasiatic was spoken c. 11,000 BC at the latest, and possibly as early as c. 16,000 BC. These dates are older than those associated with other proto-languages.