By contrast, Yamnaya Caucasus individuals from the southern steppe can be modelled as a two-way model of around 76% Steppe Eneolithic and 26% Caucasus Eneolithic/Maykop, confirming the findings of Lazaridis and colleagues 47. This two-way mix (40% + 60%, respectively) also provides a well-fit model (P = 0.09) for the Ozera outlier individual, consistent with the position in PCA and corroborating an influence from the Caucasus.Err, nope. The Ozera Yamnaya outlier, a female dated to 3096-2913 calBCE, is, in fact, a ~50/50 mix between standard Yamnaya and Late Maykop. It's a result that is totally unambiguous. There are a number of ways to demonstrate this fact. For example, with the qpAdm software that was also used by Penske et al., except with different outgroups or right pops. Please note that in my dataset the Ozera outlier is labeled Ukraine_Ozera_EBA_Yamnaya_o.
right pops: Cameroon_SMA Levant_N Iran_GanjDareh_N Iran_C_SehGabi Georgia_HG Turkey_N Serbia_IronGates_Mesolithic Russia_WestSiberia_HG Russia_Karelia_HG Latvia_HG Russia_Boisman_MN Brazil_LapaDoSanto_9600BP Ukraine_Ozera_EBA_Yamnaya_o Russia_Caucasus_EneolithicMaykop 0.554±0.031 Russia_Steppe_Eneolithic 0.446±0.031 P-value 0.00109868 (FAIL) Ukraine_Ozera_EBA_Yamnaya_o Russia_LateMaykop 0.512±0.035 Russia_Samara_EBA_Yamnaya 0.488±0.035 P-value 0.462447 (PASS)I can also do it with the Global25/Vahaduo method. And you, dear reader, can too, by putting the Target and Source Global25 coords from the text file here into the relevant fields here.
Target: Ukraine_Ozera_EBA_Yamnaya_o Distance: 2.9292% / 0.02929202 50.6 Russia_Samara_EBA_Yamnaya 49.4 Russia_Caucasus_LateMaykop 0.0 Russia_Caucasus_EneolithicMaykop 0.0 Russia_Steppe_EneolithicMoreover, here's a self-explanatory Principal Component Analysis (PCA) plot that illustrates why my Late Maykop/Samara Yamnaya combo is much better than the reference populations used by Penske and colleagues. It was done with the PCA tools here.
Russia_Caucasus_EBA_Yamnaya Russia_Caucasus_EneolithicMaykop 0.187±0.019 Russia_Steppe_Eneolithic 0.813±0.019 P-value 4.15842e-06 (HARD FAIL)Oh, and Penske et al. modeled the ancestry of mainstream Yamnaya as a three-way mixture with Steppe Eneolithic, Caucasus Eneolithic/Maykop and Ukraine Neolithic (or Ukraine N). They succeeded, but with my outgroups it's another hard fail.
Russia_Samara_EBA_Yamnaya Russia_Caucasus_EneolithicMaykop 0.177±0.017 Russia_Steppe_Eneolithic 0.706±0.026 Ukraine_N 0.116±0.014 P-value 4.73919e-07 (HARD FAIL)Admittedly, proximal models aren't easy to get right. And if you throw enough outgroups into a model, a large proportion of plausible models will fail. But I'm somewhat taken aback by these poor statistical fits. In my opinion, mainstream Yamnaya doesn't harbor any Caucasus ancestry that wasn't already present on the Pontic-Caspian steppe during the Eneolithic or even much earlier (see here). But ultimately this problem can only be solved with direct evidence from ancient DNA, so let's now wait patiently for the right samples. Citation... Penske et al., Early contact between late farming and pastoralist societies in southeastern Europe, Nature, https://doi.org/10.1038/s41586-023-06334-8 See also... Understanding the Eneolithic steppe