HISTORY LESSON!
The Devadasi Tradition is one of the most notorious parts of Indian history. Devadasis were women who were "married to God." They were the temple and royal dancers that survived under the patronage of kings and noblemen in medieval India. However, patronage tended to be a very kind word. In order to take care of themselves, the devadasis often had to resort to prostitution.
The Devadasis were the original performers of Bharatanatyam, Kuchipudi, and the like. In those times, dance education had a looser structure. Thus style evolved with the person. In the view of one of my interviewees, the devadasis' style evolved with need. Dance was there livelihood - how does one make the dance enticing and earn a living (and more patrons)? This does not refer solely to prostitution, but to entertainment as a whole. Style evolved with necessity.