Det indoeuropeiska urhemmet.

The Yamnaya culture or Yamna culture (also known as the Pit Grave culture or Ochre Grave culture) is a Copper/Early Bronze Age culture that existed roughly between c. 3,600 BCE and 2,200 BCE. This culture originated on the Pontic-Caspian steppe and is usually agreed to have developed partly out of the preceding Sredny Stog and Khvalynsk cultures.[1]

It has been argued that the Yamna culture reflects one of the earliest developments of semi-nomadic pastoralism. The evidence for this rests on the Yamna culture's possession of the domestic horse, wheeled vehicles, the composition of its livestock which was suited to the open steppe, the occasional discovery on Yamna sites of deep steppe animals such as the camel and saiga antelope, and the burials of whole family units, that have been encountered far out on the steppe.[2]

Linguistic identity and genetics
The linguistic identity of the Yamnaya culture has been prominently discussed by various archaeologists, consequently this culture is widely assumed to be the most convincing cultural correlate for the spread of Indo-European languages.[3][4] In recent years, this point of view has been further corroborated by population geneticists, who found strong support for a mass migration out of Yamnaya and into the rest of Europe.[5]

In terms of genetics, the Yamnaya remains that have been tested so far, came out largely R1b and significantly or mainly a mix between the ANE and CHG autosomal components. This indicates that the Yamnaya tribe was in the main, a mix of migrations from people of or closely related to the Mal'ta Buret' culture, as well as an indigenous tribe related to Caucasus Hunter-Gatherers.

In the context of the Indo-European urheimat debate, the Yamnaya horizon is the original source or geographic homeland, of the Kurgan theory.

The invention of the wheel
Although there are alternative hypotheses (such as the Botai culture), the domestication of the horse in particular, as well as the invention of the wheel, are often argued to have taken place in either the Yamnaya culture or its surrounding or closely related archaeological cultures, due to the Yamnaya culture's connection to the Proto-Indo-Europeans. Some of the evidence for this, aside from archaeological remains, can be seen in linguistics, where the words for wheel or wheeled vehicles in non-Indo-European languages such as Semitic *galgal-, Sumerian girgir, Kartvelian *grgar or gorgal, Mandarin gulu and Cantonese, gukluk, resemble the Proto-Indo-European root word for wheel, *kʷékʷlos,[6][7] meaning, ‘to turn, to twist’, or ‘to revolve, move around’. Due to the etymology of the PIE root word, Mallory argues it is unlikely that the Proto-Indo-Europeans borrowed the word from any of the non-Indo-European languages with similar words for wheel, however, he does leave open the possibility that the wheel may not necessarily have been invented by the Proto-Indo-Europeans. Furthermore, the spread of the Indo-European languages at such a great distance in such a short time span, as well as the evidence of its archaeologically and genetically related cultures as Afanasevo, cannot have taken place without domesticated horses and wheeled vehicles, facilitating a significant population movement.

References:
^Benjamin W. Fortson IV (2011), Indo-European Language and Culture: An Introduction, Wiley-Blackwell, ISBN 978-1405188968
^Mallory, J.P. and Douglas Q. Adams (1997), Encyclopedia of Indo-European Culture, London: Fitzroy Dearborn Publishers. ISBN 978-1-884964-98-5
^David W. Anthony and Don Ringe 2015, The Indo-European Homeland from Linguistic and Archaeological Perspectives, Annual Review of Linguistics, January 2015
^David W. Anthony (2007), The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World, Princeton University Press, ISBN 978-0-691-14818-2
^Haak et al. (2015). “Massive migration from the steppe was a source for Indo-European languages in Europe”, Nature 522, 207–211 (11 June 2015)
^James Patrick Mallory, In Search of the Indo-Europeans: Language, Archaeology, and Myth, ISBN 050005052X, p. 163
^John Farndon, The World's Greatest Idea, ISBN 1848311966, pp. 94-95