The Iberomaurusians

I can honestly say that I’ve suddenly become a more open minded individual after running the five Iberomaurusian samples from M. van de Loosdrecht et al. 2018 in my Global25 Principal Component Analysis (PCA).
They’re certainly a curious bunch. In many pairs of the 25 PCs, they sit alone, in parts of the plots that I never expected to see populated. Interestingly though, modern-day North Africans often “pull” towards them, suggesting moderate to strong genetic continuity in North Africa since the Pleistocene. The PAST datasheet used to produce the plots below is available here.

To analyze this in more detail, I ran a series of nMonte mixture models for seven North African populations using Global25 scaled data. The models show the Iberomaurusians as one of the two best reference options for all of these North African groups except the Egyptians, which, at the very least, is an outcome that fits nicely with geography.

[1] distance%=2.5772 / distance=0.025772
Algerian
Levant_BA 30.9
Iberomaurusian 24.1
Iberia_EN 17.9
Iberia_BA 14.45
Yoruba 11.85
Ethiopia_4500BP 0.8
Iberia_ChL 0
Iberia_MN 0
Iberia_Southwest_CA 0
Levant_N 0
Natufian 0
…
[1] distance%=2.7927 / distance=0.027927
Egyptian
Levant_BA 73
Iberia_BA 7.7
Ethiopia_4500BP 7.55
Yoruba 5.3
Iberomaurusian 4.45
Iberia_EN 2
Iberia_ChL 0
Iberia_MN 0
Iberia_Southwest_CA 0
Levant_N 0
Natufian 0
…
[1] distance%=1.6931 / distance=0.016931
Libyan
Levant_BA 56.8
Iberomaurusian 11.75
Iberia_BA 10.05
Yoruba 8.55
Natufian 6.55
Ethiopia_4500BP 3.4
Levant_N 2.9
Iberia_ChL 0
Iberia_EN 0
Iberia_MN 0
Iberia_Southwest_CA 0
…
[1] distance%=1.7158 / distance=0.017158
Moroccan
Levant_BA 35.3
Iberomaurusian 25.85
Yoruba 14.6
Iberia_EN 13.35
Iberia_BA 10.9
Ethiopia_4500BP 0
Iberia_ChL 0
Iberia_MN 0
Iberia_Southwest_CA 0
Levant_N 0
Natufian 0
…
[1] distance%=2.4367 / distance=0.024367
Mozabite
Iberomaurusian 29.6
Levant_BA 25.9
Iberia_EN 21.7
Iberia_BA 11.55
Yoruba 11.25
Ethiopia_4500BP 0
Iberia_ChL 0
Iberia_MN 0
Iberia_Southwest_CA 0
Levant_N 0
Natufian 0
…
[1] distance%=2.3656 / distance=0.023656
Saharawi
Iberomaurusian 36.5
Levant_BA 17.15
Levant_N 13.7
Iberia_EN 12.85
Iberia_BA 9.95
Yoruba 9.55
Ethiopia_4500BP 0.3
Iberia_ChL 0
Iberia_MN 0
Iberia_Southwest_CA 0
Natufian 0
…
[1] distance%=2.0838 / distance=0.020838
Tunisian
Levant_BA 41.85
Iberomaurusian 20.85
Iberia_BA 13.9
Iberia_EN 11.45
Yoruba 9.4
Ethiopia_4500BP 2.55
Iberia_ChL 0
Iberia_MN 0
Iberia_Southwest_CA 0
Levant_N 0
Natufian 0

Using the same methods, I also basically reproduced the ancestry proportions from the main mixture model for the Iberomaurusians in M. van de Loosdrecht et al. (~60/40% Natufian-like/Sub-Saharan African-related). But clearly, the very poor statistical fits suggest that, much like for the model in the paper, something is way off.

[1] distance%=25.4991 / distance=0.254991
Iberomaurusian
Natufian 55.85
Tanzania_Luxmanda_3000BP 21.5
Ethiopia_4500BP 21
Tianyuan 1.65
ElMiron 0
GoyetQ116-1 0
Levant_N 0
Malawi_Hora_Holocene 0
South_Africa_2000BP 0
Ust_Ishim 0
Vestonice16 0
WHG 0
…
[1] distance%=24.6253 / distance=0.246253
Iberomaurusian
Natufian 65.45
Dinka 22.9
Yoruba 9.45
Tianyuan 2.2
ElMiron 0
Ethiopia_4500BP 0
GoyetQ116-1 0
Levant_N 0
Malawi_Hora_Holocene 0
South_Africa_2000BP 0
Tanzania_Luxmanda_3000BP 0
Ust_Ishim 0
Vestonice16 0
WHG 0

The updated Global25 datasheets are available at the links below. Here’s a challenge for the people in the comments: try to come up with a coherent, chronologically sound, mixture model for the Iberomaurusians that shows a distance of less than 15%. I don’t think that this is doable just yet, and won’t be until we have at least a few more ancient forager samples from Africa and the Near East, but let’s see what happens anyway.

Global 25 datasheet
Global 25 datasheet (scaled)
Global 25 pop averages
Global 25 pop averages (scaled)

Citation…
M. van de Loosdrecht et al., Pleistocene North African genomes link Near Eastern and sub-Saharan African human populations, Science 10.1126/science.aar8380 (2018)
See also…
Unleash the power: Global 25 test drive thread

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