I have a country, inspired by Edo era where for 2000 years the people lived in a hierarchical society arranged in below classes:
1 Aristocracy - Ruling class, negligible part of population
2 Warrior class - ~8% of the population, they either
- Work in military / law enforcement
- Work privately as guards, cowboys or merchants, but serve as reserve they must train and be ready to join the standing army if there's war with the neighbors or rebellion.
3 Artisan - ~8% of the population. They live in the cities, not allowed to travel outside of it without permission of the local lord. Make and sell their wares in their shops and local market. Licensed entertainers and skilled professionals are also in this class.
4 Farmers - Bulk of the population. Must stay in the villages to work the land, not allowed to travel outside of their lord's land. Sometimes forcibly conscripted into army if aristocracy needs a lot of manpower quickly.
5 Outcasts - ~2% People doing tainted job. Sanitation workers, undertakers, prostitutes, vagrants, criminals.
Most of the time children inherit the class from their parents, but classes are ready to get rid of their worst members, and are grudgingly ready to accept from other classes if the newcomers are extremely talented. Marriages between classes are not banned though spouses with equal class and equal profession are preferred. In short some social mobility exists, both downward: incompetent aristocrat, coward warrior, untalented artisan, lazy farmer, and upward: lords needs farmers so outcasts are granted land, rich farmer pays for apprenticeship for their talented kid, ...
Is this enough selective pressure to make classes & professions to look different between each other after 100 generations (2000 / 20), similarly to differences between different breeds of dogs or horses?