The Armenian hypothesis, also known as the Near Eastern model, is a theory of the Proto-Indo-European homeland, initially proposed by linguists Tamaz V. Gamkrelidze and Vyacheslav Ivanov in the early 1980s, which suggests that the Proto-Indo-European language was spoken during the 5th–4th millennia BC in "eastern Anatolia, the southern Caucasus, and northern Mesopotamia". Recent ancient DNA research has led to renewed suggestions of a Caucasian homeland for a 'pre-proto-Indo-European'. Particularly, an admixture between the Khvalynsk and Caucasian Copper Age burials gave rise to the ancestry that later became known as a typical marker (WSH - Western Steppe Herders) of the Yamnaya pastoralists. It also lends support to the Indo-Hittite hypothesis, according to which both proto-Anatolian and proto-Indo-European split-off from a common mother language "no later than the 4th millennium BCE." These suggestions have been disputed in other recent research, which still locates the origin of the ancestor of proto-Indo-European in the Eastern European/Eurasian steppe or from a hybridization of both steppe and Northwest-Caucasian languages. The origin of the Anatolian languages according to the Near Eastern model has also been challenged because "[a]mong comparative linguists, a Balkan route for the introduction of Anatolian IE is generally considered more likely than a passage through the Caucasus, due, for example, to greater Anatolian IE presence and language diversity in the west." Hypothesis Gamkrelidze and Ivanov presented their hypothesis in Russian in 1980–1981 in two articles in Vestnik drevnej istorii. During the following years they expanded and developed their work into their voluminous book, published in Russian in 1984; the English translation of the book appeared in 1995. In English a short sketch of the hypothesis first appeared in The Early History of Indo-European Languages, published in Scientific American in 1990. Tamas Gamkrelidze published an update to the hypothesis in 2010. According to Gamkrelidze and Ivanov, the Indo-European languages derive from a language originally spoken in the wide area of Armenian Highlands, the southern Caucasus, and northern Mesopotamia. The Anatolian languages, including Hittite, split off before 4000 BCE, and migrated into Anatolia at around 2000 BCE. Around 4000 BCE, the proto-Indo-European community split into Greek-Armenian-Indo-Iranians, Celto-Italo-Tocharians, and Balto-Slavo-Germanics. At around 3000–2500 BCE, Greek moved to the west, while the Indo-Aryans, the Celto-Italo-Tocharians and the Balto-Slavo-Germanics moved east, and then northwards along the eastern slope of the Caspian Sea. The Tocharians split from the Italo-Celtics before 2000 BCE and moved further east, while the Italo-Celtics