Life is order out of chaos. Life is cold becoming warmth. So alien life was seen as scientifically unlikely. But then came a new hypothesis that says no, actually, as heat is added to groups of atoms those atoms organise to receive that energy.

Capra and Luisi (2014) provide a good entry point into complexity science; see especially Chapter 8, which discusses the self-organization of a wide range of complex systems, including molecules, cells, individual living things, and social organization in various species.