Afghanistan is made of two major linguistic groups: Pashto-speaking Patthan Afghans (who, I would suppose, are part of the Patthan tribes across the border in Pakistan) and Farsi/Dari-speaking, um, Dari Afghans (is there a more accurate designation for these Afghans?).
How different are these two groups ethnically? Are they completely separate without common ancestry? Did they originate in separate areas? Is one more indigenous to the land than the other? What other races (for example, maybe Aryan, Mongol, Greek) make up the Patthans and the Dari?
“Pathan” is just a Hindi corruption of Pakhtun or Pushtun - the population is indeed split between Afghanistan and Pakistan.
Dari speaking Afghans are for the most part Tajiks ( who are split between Afghanistan, Tajikistan, and Uzbekistan ) and Hazaras ( a name which is identified with what at one time was a Mongol sept/tribe/clan that entered with Chingisids ).
There are also Uzbek ( a name probably taken from the Golden Horde Khan Ozbeg and at one time led by Chingisid princes of the Jochid>Shaybanid line ) and Turkmen Turks and Turco-Mongolian Aimak ( another group probably stretching back to the first Chingisid eruption ), which in toto probably add up to at least another 15% of the population.
What’s indigenous? Both Tajiks and Pushtuns probably represent long-established Indo-Iranian lineages, but Afghanistan is one of the crossroads of the ancient world. Everybody and their cousin has come through that area, including Greeks, Turks/Turco-Mongols, Arabs and Iranian peoples of various stripes over the millenia. Seperating out from one another is pretty difficult - they’ve all cheerfully ( or not ) intermixed over time.
In terms of historical names, the Uzbeks are the youngest, but even they go back several centuries at this point ( and many of the people who became “Uzbeks” were probably long resident before that name became common currency anyway ).
I might add ( since I was just reading about in Richard Frye’s The Golden Age of Persia ) that the word Tajik apparently is derived from the term Tacik, itself derived from the name of an Arab tribe, the Tayyi. It was a Sogdian Persian term for the Arabs, that later was used to refer to all Muslims, particularly Iranian converts in the east. Gradually it became the name for the settled Muslim population in the east, by then essentially all Iranian as the Arab elements were absorbed.
) that the word Tajik apparently is derived from the term Tacik, itself derived from the name of an Arab tribe, the Tayyi. It was a Sogdian Persian term for the Arabs, that later was used to refer to all Muslims, particularly Iranian converts in the east. Gradually it became the name for the settled Muslim population in the east, by then essentially all Iranian as the Arab elements were absorbed.