Unlike ethnocentrism, which judges the culture, racism condemns the people. As such, it is immoral, and has led to many unfortunate episodes in human history, such as the Holocaust and apartheid in South Africa, and has often been used as an excuse to deny groups basic human and civil rights. Racism can be based on religion, language, or ethnic group. It is, however, wrong under any circumstances. Culture changes in two broad ways.
People find or adapt new methods of doing the same thing.
This is cultural change. People find new reasons to do things, or completely new things to do. For example, when a new religion is introduced to an area, there will new religious practices to be undertaken. When the Romans conquered an area, they always abolished human sacrifice. Christianity once required its members to abstain from meat every Friday.