Let's do admixture analysis on my reference population.
Since I wasn't sure what value of K would be appropriate, I ran admixture with different values of K, which defines the number of ancestral populations.
The proportion of ancestral populations for each ethnic group is given in this spreadsheet. These are the mean values for that group, calculated by averaging the ancestral proportion across all the samples belonging to that group. I have also calculated the standard deviation across each ethnic group and that's included in the spreadsheet. The higher values of standard deviation are highlighted in blue (>1%) and red (>5%). Those population groups have samples that have somewhat different ancestries.
Let's start with two ancestral populations, i.e. K = 2.
Admixture: Reference populations K=2
The second ancestral component C2 (cyan) seems to be African and the 1st one C1 (red) is maximum among East Asians. Since all populations are constrained to be made of these two ancestral components, Europeans, Middle Easterners and South Asians all have about half African ancestral component (C2) and the rest East Asian (C1). This is as I expected with the classification of humanity into African and nonAfrican.
The Fst divergences between estimated ancestral populations are as follows:
The K=3 analysis ancestral components can be roughly said to be European, East Asian and African.
Admixture: Reference populations K=3
The component C1 (red) is maximum among Europeans and is the major ancestry component for Middle Easterners, Central Asians and South Asians. Ancestral component C2 (green) is East Asian. South Asians also have a significant fraction of C2. African populations are represented by C3 (blue). Yemenese, Mozabits and Ethiopian Jews also have appreciable proportions of this African ancestral component.
Looking at the standard deviations of ancestral components for our sample groups, we see that while the Bedouin, Jordanians, Makrani, Moroccons, Mozabite, Saudis and Yemenese are mostly West Eurasian, their proportion of African ancestry vary quite a bit. The large standard deviation in Paniya is due to one sample (C1=55%, C2=42%, C3=3%) being very different (i.e. much more West Eurasian) from the other three (C1=11%, C2=85%, C3=4%).
There are also a couple of Sindhis with some African admixture. These are possibly partly or wholly Siddi.
HGDP Sindhi Samples Admixture K=3
Fst divergences between estimated populations for K=3:

C1 
C2 
C2 
0.102 

C3 
0.144 
0.182 
With four ancestral components (K=4), component C1 (red) is a South Asian ancestral component. It is maximum among central and south Indians as well as among Papuans and Melanesians. It could thus possibly related to the ASI (Ancestral South Indian) component. C4 (violet) is the African component. C3 (cyan) is the East Asian component and C2 (green) is the European component.
Admixture: Reference populations K=4
Fst divergences between estimated populations for K=4:

C1 
C2 
C3 
C2 
0.071 


C3 
0.083 
0.109 

C4 
0.152 
0.152 
0.184 
When we increase K to 5, we get the following graph:
Admixture: Reference populations K=5
Ancestral component C1 (red) is Austronesian/South Asian. It is maximum among the Papuans at 75% and is higher among South Indians as compared to Pakistanis. It is about the same component as C1 in K=4.
C4 (blue) is Southwest Asian/West Asian. It peaks in Yemeni Jews at 66% and is high among Saudis, Bedouin, Samaritans, Egyptians, and Palestinians. It's 32% among Turks, so the Southwest Asian part is dominating the West Asian in this component. Notice how Ethiopians and Ethiopian jews have about half of their ancestry from this component.
C3 (green) is the East Asian component and is the same as C3 in the K=4 analysis.
C5 (magenta) is the African ancestry component and is about the same as C4 in the K=4 analysis.
C2 (yellow) is the European component. In K=4, the European component was high among both southern and northern Europeans. Now in K=5, we have the C4 (Southwest/West Asian) component among southern Europeans, so this European component has taken on more of a north European outlook.
Fst divergences between estimated populations for K=5:

C1 
C2 
C3 
C4 
C2 
0.081 



C3 
0.084 
0.114 


C4 
0.085 
0.054 
0.129 

C5 
0.154 
0.165 
0.186 
0.155 
Let's continue this admixture analysis for higher values of K.
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