Kaunas, Lithuania. Kurgan hypothesis In 1956 Gimbutas introduced her Kurgan hypothesis, which combined archaeological study of the distinctive Kurgan burial mounds with linguistics to unravel some problems in the study of the Proto-Indo-European (PIE) speaking peoples, whom she dubbed the "Kurgans"; namely, to account for their origin and to trace their migrations into Europe. This hypothesis, and her method of bridging the disciplines, has had a significant impact on Indo-European studies. During the 1950s and early 1960s, Gimbutas earned a reputation as a world-class specialist on Bronze Age Europe, as well as on Lithuanian folk art and the prehistory of the Balts and Slavs, partly summed up in her definitive opus, Bronze Age Cultures of Central and Eastern Europe (1965). In her work she reinterpreted European prehistory in light of her backgrounds in linguistics, ethnology, and the history of religions, and challenged many traditional assumptions about the beginnings of European civilization. As a Professor of European Archaeology and Indo-European Studies at UCLA from 1963 to 1989, Gimbutas directed major excavations of Neolithic sites in southeastern Europe between 1967 and 1980, including Anzabegovo, near Štip, Republic of Macedonia, and Sitagroi and Achilleion in Thessaly (Greece). Digging through layers of earth representing a period of time before contemporary estimates for Neolithic habitation in Europe – where other archaeologists would not have expected further finds – she unearthed a great number of artifacts of daily life and religion or spirituality, which she researched and documented throughout her career. Three genetic studies in 2015 gave support to the Kurgan theory of Gimbutas regarding the Indo-European Urheimat. According to those studies, Y-chromosome haplogroups R1b and R1a, now the most common in Europe (R1a is also common in South Asia) would have expanded from the Russian steppes, along with the Indo European languages; they also detected an autosomal component present in modern Europeans which was not present in Neolithic Europeans, which would have been introduced with paternal lineages R1b and R1a, as well as Indo-European languages. Late archaeology Gimbutas gained fame and notoriety in the English-speaking world with her last three English-language books: The Goddesses and Gods of Old Europe (1974); The Language of the Goddess (1989), which inspired an exhibition in Wiesbaden, 1993–94; and the last of the three, The Civilization of the Goddess (1991), which, based on her documented archaeological findings, presented an overview of her conclusions about Neolithic cultures across Europe: housing patterns,