Some background for evolution-related posts — rf, march 2014
Broad Sense Evolution / Universal Darwinism / Generalized Evolutionary Theory
Evolution is not just part of biology. It happens whenever there is a carrier of information, sources of variation, and mechanisms of selection.
The study of evolution has become an integral part of biological science. But basic concepts of evolution have also been applied to other fields: we can speak of cultural evolution, with memes taking the place of genes as units of inheritance; of evolutionary psychology, recognizing the many effects that our evolutionary history has had on our thought processes; and of evolution-based computer simulations in software development, mathematics, economics, and many other fields.
All of these different kinds of evolution involve a particular kind of cause and effect. At the most basic level, all types of evolution are made up of three elements:
• Continuity / inheritance: a carrier of information that can replicate, allowing the information to reproduce, increase and continue through time.
• Variation / diversification: factors that cause some of the information to change, creating variants.
• Selection / environment: ways in which some of those variants are selected to continue reproducing, while others are selected to not continue.
In biological evolution, the primary carrier of information is genes made of nucleic acids like DNA, gene variation involves various mutations and recombinations, and genes increase in frequency when individuals that carry them have more descendants. In cultural evolution, the primary carrier is memes that make up traditions such as language and art, variation can be introduced by communication and other experiences, and what continues is mostly selected by use and disuse.
The environment is a key part of evolution by natural selection: it is the thing that selects; the ultimate cause of differential reproduction. Although selection for some characteristics can be related to particular environmental conditions, the total environment that selects includes everything that might influence reproduction. For genes, it includes the living and non-living external factors that the carrier organism encounters (temperature, food, predators, etc), as well as the physiological and psychological environments inside each individual (how gene products interact with each other). For human genetic evolution, it also includes the cultural environment: language, traditions, habits and other behaviors that a person must deal with. And all these aspects of culture are evolving together under the influence of other cultural elements, as well as the physical and biological environments. Genes and memes co-evolve together in a vast dance of universal contingency.
If environmental conditions stay the same, then the same characteristics will always be selected for, and subsequent generations will become progressively better adapted to those conditions. But if the environment changes, then different characteristics will be select for, and evolution will take a different course. Since changing environments are the norm, the genetic map and the environmental territory are often out of sync.
The idea of evolving thoughts was mentioned by Jacques Monod in his classic book about evolution, Chance and Necessity (1970): “Ideas have retained some of the properties of organisms. Like them, they tend to perpetuate their structure and to breed; they too can fuse, recombine, segregate their content; indeed, they too can evolve, and in this evolution selection must certainly play an important role”
In The Selfish Gene (1976), Richard Dawkins coined the word “meme” for a related concept: “Examples of memes are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation.”
More about generalized evolutionary theory / Universal Darwinism:
Susan Blackmore discussed the evolutionary algorithm (and proposed “temes” – technological replicators) in a 2010 New York Times blog titled The Third Replicator. Some good references and comments are included.
A number of good introductions to evolution are available online, such as an illustrated slide show from from UC Berkeley (evolution.berkeley.edu/evosite/evo101/), and more detailed descriptions, such as at Wikipedia (en.wikipedia.org/wiki/Introduction_to_evolution, en.wikipedia.org/wiki/Evolution_%28disambiguation%29).
In Emptiness and Brightness (2013), Don Cupitt proposed “universal contingency” as a basic part of the world view of the evolving religion of our New Axial Age. It’s a more cogent and descriptive term for a basic meaning of the traditional Buddhist concept of “dependent origination”, and Thich Nhat Hanh’s more poetic “interbeing”.