Proliferation with Variation and Motility: a First Principle in Biology

Abstract

What properties have been bestowed by the Last Universal Common Ancestor (LUCA) on its descendants? We concluded that LUCA was a minimal autonomous agent, i.e., it was the organism that originated the notion of “common descent” and expressed the same default state of the diverse living organisms that biologists study today. Namely, LUCA proliferated constitutively, generating variation and movement. The organism's ability to proliferate enabled natural selection to occur amid a constantly varying environment. All along, the historical record shows, however, that most biologists have implicitly interpreted data collected on the development of multicellular organisms under the opposite premise, namely, that quiescence was the default state of their cells. Based on both empirical evidence and theoretical considerations, we argue that adopting proliferation with variation and motility as the default state for all cells is consistent with evolutionary theory. In addition, adopting this fundamental first principle opens new productive vistas into normal and pathological developmental processes in multicellular organisms and in their interactions with the environment.