Evolution & Emergence
Evolution and emergence are not the same thing. Evolution is the process of change within a particular level. Emergence is the creation of a new level of organization through the coming into existence of one or more self-sustaining systems, or agents. These agents often co-exist in populations of other agents which are more or less similar to one another, for instance a species, a tribe, or an ecology of organisms from a variety of species.
From The Chaos Point. Reproduced with permission from the author.
When we talk of evolution we are usually talking about it in the Darwinian sense: natural selection on a population of agents from the same “species”. In this sense, we think of the population or species itself as being the thing that evolves; after all, the individual agents are born and die, but don’t adapt over their own lifetime in the way the species does. But this is a somewhat arbitrary distinction, for surely individual agents can and do “evolve” in that that they change over time. A most striking example of agent evolution is of course the development of an embryo into a mature adult. The mechanisms of change in evolutionary processes are varied, but when we talk of Darwinian evolution we are focusing on a particular dynamic of selection, heredity and mutation.
When we identify a species, we are in fact acknowledging emergence. The organisms (i.e. agents) simply exist: they each have a unique phenotype (i.e. body) and unique genotype (thanks to mutation and sexual reproduction).* Different “species” then become agents at a higher level of organization. We can talk about them as having agent-like properties such as stability and self-repair (more on this in a later post). A species evolves (as an agent) over the course of reproductive generations of its constituent parts, the organisms.
Other examples of the emergence of agents at a higher level include: multi-cellular organisms, culture, ice, separation of genotype/phenotype, emotion, protons, self, computers, and just about every “type” of thing you can think of. This is a strong, broad claim that is the subtext of this entire blog. If you are not convinced, reserve judgment and continue reading with an open mind.
* Even when we talk of single celled organisms and say one is an exact clone of another, the reality is that there are many point mutations which make their DNA non-identical. We observe that between certain sub-populations the agents interact in such a way that causes reproduction and the creation of more, similar agents. The species boundary is fuzzy though, as evidenced by the existence of some inter-species mating and also the phenomenon of genetic drift. The concept of same or different “species” is just a model. But it is a good model because it has descriptive and prescriptive power.
POSTSCRIPT: An excellent summary of emergence can be found at Wikipedia (which, BTW, is itself an emergent agent).