how can culture change and established culture affect the development of diffusion of material culture?

When a certain number of people start to make their own culture, gather number of people and start a new culture.

Now there are other ways to due to which culture changes, in which the first reason in intact, the other reason may be due to the natural disaster, migration from one region to other.

After changing the culture, it sure is very challenging to survive among others. Since there are limited amount of people in a certain culture than it is sure hard to handle the development.