The term symbiosis was defined by the German mycologist Anton De Bary (1879) as meaning the "living together" of "dissimilar" or "differently named" organisms

Today, in most current biological literature, it is taken to mean "mutualistic biotrophic associations" (biotrophy: one partner requires a nutrient that is a metabolic product of the other partner.) For example, lichens consist of algal and fungal components in nearly equal mass in symbiosis. 

See Lynn Margulis' Serial Endosymbiosis theory in prokaryote / eukaryote

Kisho Kurokawa, a Japanese architect who was a leader of the Metabolist Group, proposes the philosophy of symbiosis as a philosophy for the twenty-first century, the "age of life," in which "it is the very plurality of life that possesses a superior value," and when "a richly creative, schizophrenic personality reigns supreme." For Kurokawa, "In the coming age, the machine-age ideal of universality will be exchanged for a symbiosis of different cultures." (p.25) Kurokawa advocates a hybrid intercultural architecture through the symbiosis of of tradition, environment, and advanced technology. This vision of heterogeneity and assemblage allows for a tension between the part and the whole. (cf local / global)