Abstract
BACKGROUND: For many years, scientists have accepted Darwin's conclusion that "Survival of the Fittest" involves successful competition with other organisms for life-endowing molecules and conditions. SUMMARY: Newly discovered "partial" organisms with minimal genomes that require symbiotic or parasitic relationships for growth and reproduction suggest that cooperation in addition to competition was and still is a primary driving force for survival. These two phenomena are not mutually exclusive, and both can confer a competitive advantage for survival. In fact, cooperation may have been more important in the early evolution of life on earth before autonomous organisms developed, becoming large genome organisms. KEY MESSAGES: This suggestion has tremendous consequences with respect to our conception of the early evolution of life on earth as well as the appearance of intercellular interactions, multicellularity and the nature of interactions between humans and their societies (e.g., social Darwinism).