David Reich (geneticist)

"Ancient DNA available from this time in Anatolia shows no evidence of steppe ancestry similar to that in the Yamnaya (although the evidence here is circumstantial as no ancient DNA from the Hittites themselves has yet been published). This suggests to me that the most likely location of the population that first spoke an Indo-European language was south of the Caucasus Mountains, perhaps in present-day Iran or Armenia, because ancient DNA from people who lived there matches what we would expect for a source population both for the Yamnaya and for ancient Anatolians. If this scenario is right the population sent one branch up into the steppe-mixing with steppe hunter-gatherers in a one-to-one ratio to become the Yamnaya as described earlier- and another to Anatolia to found the ancestors of people there who spoke languages such as Hittite."

"People often think that Europeans are homogeneous group that arrived in a simple way there maybe 40 or 50 thousand years ago maybe based on the archaeology and just kind of sat there until they became the Europeans they are today, but that's probably not true: the Europeans today are a replacement population who came in much more recently and replaced the people who were there originally 40 thousand years ago."

"The mixture of highly differentiated populations is a recurrent process in our history."

"About ten thousand years ago there were at least four major populations in West Eurasia — the farmers of the Fertile Crescent, the farmers of Iran, the hunter-gatherers of central and western Europe, and the hunter-gatherers of eastern Europe. All these populations differed from one another as much as Europeans differ from East Asians today. Scholars interested in trying to create ancestry-based racial classifications, had they lived ten thousand years ago, would have categorized these groups as "races," even though none of these groups survives in unmixed form today."

"Ideologies that seek a return to a mythical purity are flying in the face of hard science."

"“Whites” are not derived from a population that existed from time immemorial, as some people believe. Instead, “whites” represent a mixture of four ancient populations that lived 10,000 years ago and were each as different from one another as Europeans and East Asians are today."

"We warn that models in population genetics should be treated with caution. Although they provide an important framework for testing historical hypotheses, they are oversimplifications. For example, the true ancestral populations of India were probably not homogeneous as we assume in our model, but instead were probably formed by clusters of related groups that mixed at different times. (Reich et al. 2009: 492)"

"The circularity of the ‘Ancestral North Indians’ (ANI) vs ‘Ancestral South Indians’ (ASI) concept is another case in point. Reich (2018) admits that he thought it up overnight simply to avert serious differences with his Indian collaborators. No precise definition was ever given to these two supposedly highly distinct groups; they were simply stated to be ‘genetically divergent’ (Reich et al. 2009) and were used in several subsequent studies as though they had been rigorously established. Elsewhere (Danino 2014), I showed that the populations sampled were very seriously restricted, since 18 states of India had either no representation or only one group represented in the 2009 study. Despite such a skewed distribution, Reich et al. exuded confidence in the newly coined terms and found it ‘tempting to assume that the population ancestral to ANI and CEU [Europeans] spoke ‘‘Proto-Indo-European’’ … ’ (Reich et al. 2009, p. 492) – a gratuitous association built, again, on circularity."