Textbooks often say the Panthers were violent and anti-white. For example, the Teacher Curriculum Institute's "History Alive! The United States" reads, "Black Power groups formed that embraced militant strategies and the use of violence. Organizations such as the Black Panthers rejected all things white and talked of building a separate black nation." In reality, the Panthers believed in using violence only in self-defense. This passage also tries to separate the Panthers from "nonviolent" civil rights groups. The Panthers didn't begin out of thin air, however, but developed from their relationships with other civil rights organizations.
Summarize this passage into one sentence.

The constant presence of diseases or infectious agents within a given geographic area or population group. it may also refer to the usual prevalence of a given disease with such area or group. it includes holoendemic and hyperendemic diseases. a holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). a hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. so probably family history.