Major Evolutionary Transitions in Individuality

* Article: Major evolutionary transitions in individuality. Stuart A. West, Roberta M. Fisher, Andy Gardner, and E. Toby Kiers. PNAS August 18, 2015 112 (33) 10112-10119; doi

URL = https://www.pnas.org/content/112/33/10112

Abstract

"The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven’t taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict."