Significance of seven steps in Golu

My name is Sailaja .s and my mother tongue is telugu. we have tradition of decorating dolls during sankranthi festival.although i am a telugu person i have always been a tamilian socially. my mothers close friends and neighbours were tamilians and so are mine.

Actually the point is when we arrange dolls for golu is there a particular way for arranging them? somewhere i read that the seven steps indicate the seven stages of evolution .so we begin with water life i.e.fishes, tortoises,then plants,animals, passing on to human settlements i.e. huts, marriage,etc.the shopkeeper indicates commercial life . the 5th step should have small gods(?! ) and the top most for perimal or pillayar or both. The park ,stadium, playground etc are side additions.

I have visited many homes during golu (ofcourse by invitation) to see their decoration and also for the yummy sundal prasadam.even some uploaded pictures of golu also ihave seen.not everyone seems to follow the same style . talent apart afterall it is a tradition tobe followed. dont u think so.

Can anyone tell me about the seven steps story? maybe some senior members can enlighten me on this.