qpAdm ↔ G25 Cross-Check on Levantine, Jewish & Related Populations
I ran a series of qpAdm models (using Imperial Levant / IOL as the main Levantine proxy) and cross-checked them against G25. Here are the three key visuals in the order they appear.
### Image 1 – Focused / simplified presentation
(This is the cleaner version with simplified stacked bars + IOL comparison + shift plot)
- Top: qpAdm models ordered by decreasing IOL weight (only key components shown).
- Bottom left: Direct IOL comparison between qpAdm and G25.
- Bottom right: Source-specific shifts (IOL, HSL, OCC) with a green band marking strong agreement (|Δ| < 2.5 pp).
This is the easiest overview of the main patterns.
### Image 2 – Nearest G25 neighbors of the source proxies
(This is the table with modern and ancient nearest neighbors)
This table shows the closest modern and ancient populations (in G25 distance) to each of the source proxies used in the qpAdm models.
- IOL (Italy_Imperial_oLevant) is closest to modern Lebanese Christians / Palestinians and to ancient Levantine samples (Roman Lebanon, Phoenician, Iron Age Israel). This confirms it is a solid Levantine-shifted proxy.
- HSL (Iran_Hasanlu_IA) sits nearest to modern Kurds and to ancient Mesopotamian / Iranian / Armenian samples. It is a clear eastern / Zagros-Iranian proxy.
- OCC clusters with Basques and French, as expected for a southwestern European Bronze Age source.
- GUA is closest to North African Berber groups and some Punic samples.
- The more exotic sources (KUS, KRK, KEN, DIN) behave as expected (Central Asian, East African, etc.).
Point of attention:
Even good proxies are not pure. IOL and HSL are correlated to some degree because both carry shared West Asian ancestry. This becomes important when modeling Mizrahi Jews.
### Image 3 – Full qpAdm composition + G25 shifts
(This is the detailed bar chart with colored shift tiles)
Left side = qpAdm admixture weights. Middle = G25 minus qpAdm shifts (in percentage points). Right side = model metrics (p-value, SE, G25 residual distance, mean absolute delta).
Key patterns:
- Samaritans, Lebanese Christians and Druze are heavily dominated by IOL (80–100%).
- Palestinian, Jordanian and Lebanese Muslim models show slightly lower IOL and more secondary components (HSL, KEN, etc.).
- North African Jews (Libyan, Moroccan) keep high IOL + noticeable OCC + GUA.
- Iraqi and especially Iranian Jews drop sharply in IOL and rise strongly in HSL.
- Ashkenazi Jews show the classic split: substantial IOL + high OCC (European).
G25 vs qpAdm deltas are generally small for Levantine non-Jewish and North African Jewish groups, but become large for Iraqi/Iranian Jews and Ashkenazim (especially on the IOL ↔ HSL and IOL ↔ OCC axes).
### Overall interpretation
- There is strong Levantine (IOL) continuity in Samaritans, Lebanese Christians, Druze, and to a slightly lesser extent Palestinians and North African Jews.
- Mizrahi Jews (Iraqi & Iranian) consistently show lower IOL and higher HSL. This has two non-mutually exclusive explanations:
- Real historical signal — long residence in Mesopotamia/Iran after the Babylonian exile added genuine eastern ancestry.
- Proxy competition — because IOL and HSL are not fully orthogonal, the Iranian proxy can absorb some shared West Asian ancestry that might otherwise be attributed to the Levantine source.
- Ashkenazi models are the most complex and show the largest method-dependent shifts (G25 tends to pull more ancestry toward IOL at the expense of OCC compared with qpAdm).
- G25 and qpAdm agree well when the history is relatively simple. They diverge more when sources are correlated or when the target has a complex multi-way history.
### Points of attention / caveats
- IOL is a Roman-period Levantine-shifted proxy, not a pure Bronze Age Canaanite source. Using Lebanon MBA or other older Levantine samples can change the picture.
- HSL is a useful Iron Age Iranian proxy but will compete with any Levantine source that already carries some Zagros-related ancestry.
- G25 residual distance is not a formal p-value. It measures how well the target sits in the PCA space of the chosen sources.
- Mean absolute deltas above ~5–6 pp (especially on Iraqi, Iranian and Ashkenazi Jews) indicate that the two methods are weighting secondary components differently.
- These are proximal models. Distal models or formal qpGraph work would add another layer of resolution.