later than the 4th millennium BCE." Wang et al. (2018) note that the Caucasus served as a corridor for gene flow between the steppe and cultures south of the Caucasus during the Eneolithic and the Bronze Age, stating that this "opens up the possibility of a homeland of PIE south of the Caucasus." However, Wang et al. also acknowledge that according to genetic evidence, an origin of the Proto-Indo-European language in the North Pontic/Caucasus region is possible, noting: Kristian Kristiansen, in an interview with Der Spiegel in may 2018, stated that the Yamnaya culture may have had a predecessor at the Caucasus, where "proto-proto-Indo-European" was spoken. Lazaridis et al. (2022) outline genetic evidence for Reich and Wang's "south of the Caucasus" model. The authors suggest a primary Indo-Anatolian homeland in Western Asia and/or the Caucasus, with the Eurasian steppe serving as a secondary Indo-European homeland after the Anatolian branch split off. Criticism J. Grepin wrote in a review (1986) in the Times Literary Supplement the model of linguistic relationships is "the most complex, far reaching and fully supported of this century". Robert Drews says (as published in 1988) that "most of the chronological and historical arguments seem fragile at best, and of those that I am able to judge, some are evidently wrong". However, he argues that it is far more powerful as a linguistic model, providing insights into the relationship between the Indo-European and the Semitic and Kartvelian languages. David Anthony in a 2019 analysis also criticizes the "southern" or Armenian hypothesis (replying to Reich, Kristiansen, and Wang). He finds that the Yamnaya derived mainly from Eastern European hunter-gatherers (EHG) and Caucasus hunter-gatherers (CHG), and suggests a genetic and linguistic origin of proto-Indo-Europeans (the Yamnaya) in the Eastern European steppe north of the Caucasus, from a mixture of these two groups. Anthony argues that the roots of proto-Indo-European formed mainly from a base of languages spoken by Eastern European hunter-gatherers, with some influences from the languages of Caucasus hunter-gatherers. According to Anthony, hunting-fishing camps from the lower Volga, dated 6200-4500 BCE, could be the remains of people who contributed the CHG-component, migrating from the south-east Caucasus, who mixed with EHG-people from the north Volga steppes. The resulting culture contributed to the Sredny Stog culture, a predecessor of the Yamnaya culture. Anthony cites evidence from ancient DNA, that the Bronze Age Maykop people of the Caucasus (previously proposed as a