Multilateral Evolutionary Transitions in Individuality (ETIs)

Abstract

Evolutionary transitions in individuality (ETls) occur when a group of individual units become integrated such that the level natural selection acts on shifts to the group as a single entity. Egalitarian transition: Group is formed by distinct units that come together to form a new higher level organism. Fraternal transition: Group is formed by similar units that combine to form a new higher level organism. These two transitions are not mutually exclusive and can co-occur in some cases, creating the need to define a new category: multilateral transitions. We applied a consolidated list of individuality criteria to two proposed multilateral transitions, Ulva and corals, to determine if they represent an ETI.