@Reformed J This is a further elaboration on our discussion and I made a thread because I think such extensive posts deserve it.
Here is the link for people who want background context.
If we reframed the question to where today's definitions of Somali identity stem from, it is doubtful it would go beyond the early medieval period. The definition of our historical identity recollection is considerably tied to Islam to the point where it would be impossible to define without it as it would construct away massive impactful process realities that resulted in who we are today. Drawing perspective from ethnographic conceptualization, a person who divorces themselves from that history and doesn't identify with the Islamic ways, our contextual baseline of who we are and our civilization down to giving explanations for views and actions on a personal level, will struggle with their identity since it is, by definition, ethnoreligious-like. The concrete answer to this question cannot wholly go beyond Islam, as it makes up about 2/3 of the definition.
A timeline breakdown goes like this: ~2700 years before the present is the nascent stage of early Somalis, then several punctuated steps of historical, cultural, state, and economic proportions, with the latest ground definition being somewhere in the medieval age --, still I would say 2700 years ago is the original spring of ethnogenesis that gives the context of a set group that later would change. The economic existence was entirely mature many centuries before Islam came. Adal, for example, was a late height of what Somalis had fashioned for economic infrastructure since antiquity, already running a distinct economic sphere and more expansive and coherent in its impact on the region, I might add, compared to the Axumite and their later Habash descendants who I have to emphasize was a totally separate entity. The cultural and traditional aspects were kept, in large parts, especially the agropastoral-trading synergy existing as a coherent economic system. When you examine the characteristics through the backdrop of all the knowledge we have, the continuity is salient, with changes being very complimentary developments rather than abrupt paradigm shits.
I have already proven that through genetic research, Somalis considered themselves of the same people group by how they had high gene flow among themselves but excluded all Ethiopian groups. You can never reconcile this with the notion that those many clans considered themselves as different ethnic groups; otherwise, you would have a difficult (impossible and irrational) time explaining how other Ethiopian ethnic groups are entirely out-group. Such asymmetry is, by definition, the highest-marked definition of an in-group. Our genetic history makes no sense if our ancient ancestors did not consider themselves the same -- where clan identity functions as a separate dual identity of more immediate kin rather than conflicting with the identity of a concept of broader peoplehood or as a lesser form, "race" or tribe. You could be a hardcore clan-ist but be genetically homogenous with a rival clan because of a deep, constant history of mixing, coupled with where the ultimate origin is the same in terms of deep lineage. If every clan was a separate ethnic group, you would see genetic structuralization that reflects this and much wider diversity, with more pronounced regional population assortment results.
Here is a previous post going into different things, undeniably, substantiating the topic:
Heck, the TVD matter thegoodshepherd brought up proves this even further.
Internal TVD (the red is Somali while the rest are other Ethiopian groups):
View attachment 317454
External TVD:
View attachment 317455
"External" really highlights this tremendously. It says that those Ethiopian Cushitic and Semitic-speaking groups have a genetic variation that does not need outside sources to explain their within-group differentials, while Somalis differ tremendously with that. Somalis are not a variation of Ethiopian diversity, existing on their own distinct cluster of population history. You can see on Fst and TVD how relational value in genetic diversity has its own closed-off population history dimension. So when people come and say that Somali is not an ethnicity or it is a recent invention, or even claim the group that we refer to as Somalis today are only close because of late homogenization, these people lack any meaningful insight on the matter to pathetic proportions. They talk without actually providing anything but their senseless irrationality. Every genetic study underscores my exact point. This late invention of Somali as peoplehood argumentation is unequivocally false nonsense.
These deviants that regurgitate unproven opinions that never engage with the actual research will claim all kinds of crap, speaking against the reality of research itself -- these are frauds.