Just look at the beginning of life and thats the answer, single cell bacteria formed primitive physiology and the egg is only a method to reproduce.

It is a very shallow question in scientific terms, before there are male & female, the physiology change sex to reproduce, the process has been refined by generations and the state of evolution to date is categorized into Mammal, Reptile, Amphibian...

If you continue to ask this question, it means you have no knowledge of evolution, go tell people to stop insulting themselves.

This post has been edited by 3dassets: Aug 10 2010, 02:32 PM