I don't know if others talked about this, but Somalia's environment and proto-Somalis pastoralism is what kept Somalis relatively homogeneous.
There was this map for which population is the closest to Savanna Pastoral Neolithic (samples dated from 1400 BC - 340 AD), in my opinion this shows that those who lived in harsh location like Somalia has less genetic diversity, and if Somalia was more inhabitable like ethiopian highlands, we would have been more diverse genetically and linguistically. Somaliweyne is large area, and having one single dominant group speaking almost the same langauge is very much unusual without ethnic cleansing or colonialism.
There was this map for which population is the closest to Savanna Pastoral Neolithic (samples dated from 1400 BC - 340 AD), in my opinion this shows that those who lived in harsh location like Somalia has less genetic diversity, and if Somalia was more inhabitable like ethiopian highlands, we would have been more diverse genetically and linguistically. Somaliweyne is large area, and having one single dominant group speaking almost the same langauge is very much unusual without ethnic cleansing or colonialism.
