"At what point a complex organic macro-structure becomes 'alive' ?"

"At what point a complex organic macro-structure becomes 'alive' ?"
Links:
[1] http://edge.org/annual-question/what-questions-are-you-asking-yourself
[2] http://edge.org/inthenews/what-questions-are-you-asking-yourself
[3] http://edge.org/contributors/what-questions-are-you-asking-yourself
[4] http://edge.org/responses/what-questions-are-you-asking-yourself
[5] http://edge.org/print/response-detail/11097
[6] http://edge.org/memberbio/marcelo_gleiser