• Robert Park provided the general framework for the ecological theory of the city. Park began his career as a journalist reporting on urban affairs varying from corruption, the issue of immigrant communities, crime etc. But his persistent interest in the grand questions made him come back to the university. He studied philosophy at Harvard and social thought with Simmel in Berlin and obtained his Ph.D. from Heidelberg. From 1913 onwards he began teaching at Chicago University.
  
  
• Before further discussing the ecological school let us look at the concept of ecology as it is used in biological sciences. It could be said that:

Ecology refers to the study of interrelationship of organisms and their environment as well as the totality or patterns of relations between organisms and their environment.

The Chicago sociologists used this concept in analyzing the city.

• During this period animal ecologists were coming up with results that pointed out how rat behaviour differed as the density changed. More density showed more infant neglect, violent behaviour etc. The argument that human ecologists took up was physical conditions have impact on human behaviour. And human beings adapted themselves in different way than animals.