Emergence: Encyclopedia II - Emergence - Emergent structures in nature

Emergence - Emergent structures in nature

Emergent structures are patterns not created by a single event or rule. There is nothing that commands the system to form a pattern, but instead the interactions of each part to its immediate surroundings causes a complex process which leads to order. One might conclude that emergent structures are more than the sum of their parts because the emergent order will not arise if the various parts are simply coexisting; the interaction of these parts is central.

A biological example is an ant colony. The queen does not give direct orders and does not tell the ants what to do. Instead, each ant reacts to stimuli in the form of chemical scent from larvae, other ants, intruders, food and build up of waste, and leaves behind a chemical trail, which, in turn, provides a stimulus to other ants. Here each ant is an autonomous unit that reacts depending only on its local environment and the genetically encoded rules for its variety of ant. Despite the lack of centralized decision making, ant colonies exhibit complex behavior and have even been able to demonstrate the ability to solve geometric problems. For example, the ant colonies routinely find the maximum distance from all colony entrances to dispose of dead bodies.

Besides emergence in ant colonies, which is like other emergent structures in social insects mainly based on pheromones and chemical scents, emergence can be observed in swarms and flocks. Flocking is a well-known behavior in many animal species from swarming locusts to fish and birds. Emergent structures are a favorite strategy found in many animal groups: colonies of ants, piles of termites, swarms of bees, flocks of birds, herds of mammals, shoals/schools of fish, and packs of wolves.

Emergent structures can be found in many natural phenomena, from the physical to the biological domain. The spatial structure and shape of galaxies is an emergent property, which characterizes the large-scale distribution of energy and matter in the universe. Weather phenomena with a similar form such as hurricanes are emergent properties, too. Many speculate that consciousness and life itself are emergent properties of a network of many interacting neurons and complex molecules, respectively.

Life is a major source of complexity, and evolution is the major principle or driving force behind life. In this view, evolution is the main reason for the growth of complexity in the natural world. If we speak of the emergence of complex living beings and life-forms, we refer therefore to processes of sudden changes in evolution.

There is also a view that the beginning and development of evolution itself can be regarded as an emergent property of the laws of physics in our universe, or contrary to this the opposite view that the laws of phyiscs have like their constituents emerged during the course of time (in which case "evolution" and "emergence" would be the most fundamental principles in the universe).

Adapted from the Wikipedia article "Emergent structures in nature", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki