Answer:
Mountain ranges were a great physical barrier for early human tribal groups. These were often very hard to cross, or simply unpassable.
These ranges isolated different human groups from each other, leading to the formation of very different cultural identities.
For example, the cultures that would develop north of the Himalayas, in the TIbet, are very different from the cultures that developed south of the Himalayas, in the Indus and Ganges river valleys.
We can find examples like these all over the world. In fact, mountains are still a physical barrier, and are harder to settle than lowlands, even if we have a lot of technology that early human tribal groups did not have.
