Tuesday, 29 November 2016

The evolution of observers and observations

Here's a draft of a book chapter I have written on the topic of observer and observation evolution.


One of the places where mainstream physics has come closest to embracing Darwinism involves the role of observers. Physicists identified the role selection of observers plays, and identified it as the cause of goodness of fit between man and his environment - in the form of life-friendly physical laws and a stable planetary home.


Historically, the evolution of observers was first studied by a physicist called Brandon Carter in the 1970s. One of the ideas he came up was was that physical constants having values that made the universe habitable was not due to chance or an intelligent designer. It was no accident that we observed a universe with life-friendly physical laws, since it could not be otherwise: any observers in universes with physical laws that were not life friendly would rapidly perish. This idea was christened "the anthropic principle" and it was contrasted with the Copernican principle - which states that we are not in a special place in the universe. According to the anthropic principle we are in a very unusual place in the universe - one suitable for the evolution of humans over billions of years.

The result of the need for life-friendly physical laws is an adaptive fit between the universe and living systems inside it. The physicists didn't describe what they had discovered as an "adaptive" fit. Instead they said that the universe was 'fine tuned' for life. Most of the physicists involved didn't seem to link these ideas to evolutionary theory. Instead they seemed to consider it to be an entirely new area of science which they had discovered, one that could explain the appearance of design without invoking a designer. They did, however use the terminology of 'selection' to describe their findings - mirroring the terminology used in evolutionary theory. Retrospectively, it seems obvious that they were just applying Darwin's discovery to human observers.

Observation selection

A subsequent development was the discovery that a similar idea could be applied to observations, as well as to observers. Observations may be filtered in a number of ways - both before and after arriving at the senses. For example, publication bias filters information before it reaches an observer. An observer's expectations and preconceptions might then go on to filter information further before it reaches consciousness.

Observation of the observable

From one perspective, observation selection is one type of selection in the nervous system among many. Filters also control whether information is stored, when it is retrieved, and when it is forgotten. Still more filters are applied to ideas, action plans and motor outputs. However, if you look at the situation another way, observations seem to be fundamental - since all knowledge gains are made through observation. Observations are the basis of everything an organism knows. Everything else consists of inferences derived from observations. This gives observations a primary status. For example, if a fruit fly in an scientists's experiment dies, that's a case of natural selection. However the scientist doesn't learn about it until an observation is made. We can say that survival of the fittest is a special case of observation of the observable. This results in a reformulation of evolutionary theory puts observers at the heart of the theory. This broadly mirrors the changes in physics that happened at the turn of the last century, when it was discovered that observers played a surprisingly central role in physics.

Observation reproduction

Selection is only part of Darwinism. That many observers reproduce is perhaps too obvious to mention. However, observation reproduction merits a few comments. Behavioral reproduction is ubiquitous in human cultural transmission. It is widely agreed that humans often copy the behavior of other humans via behavioral imitation. However, behavior is only one side of behavioral imitation. To be copied, behaviors have to also be observed. Observations reproduce during this process just as behaviors do. To give an example of an observation that catalyzes its own reproduction consider the observation of yourself, snorting cocaine. Such an observation is often followed by more similar observations. This is a simple case of observation reproduction.

Beyond survival and reproduction

Observation selection illustrates how Darwinian dynamics can involve more than survival and reproduction. Observation selection also filters out things that are hidden from the observer. This allows evolutionary theory to be applied to cases where the observation of entities is based on their visibility - rather than because they and their ancestors survived and reproduce. Survival and reproduction are important determinants of what we observe, but they are not the only factors involved.


The idea that the visible universe is the product of selection effects suggests that the visible universe is part of a multiverse. It which case it would be helpful to know the size of the multiverse - and which parameters are free to vary in it. Alas we can only observe our small corner of the multiverse. This leads to a difficult inductive inference problem with very little data to go on. The concept of a "reference class" is sometimes used to denote the set of objects being selected from. When dealing with other possible worlds it isn't always clear what the set of worlds being selected from consists of - since we only see one world.

Brandon Carter's Ultra-Darwinism

One of the physicists who did recognize links to Darwinism was the originator the idea in the first place: Brandon Carter. He wrote in 1992 that: "anthropic selection should be considered as an adjunct to ordinary natural selection". He proposed that the union of anthropic selection and natural selection be called 'Ultra Darwinism'. That's pretty much the same thing that I am saying - except that Brandon used a different name. However, I would emphasize that the topic is mostly just applying basic Darwinian principles to observers and observations. There are a few other topics involved too - for example, the maximum entropy principle is used to handle ignorance. However, this is mostly ordinary Darwinism applied to observers and observations.


The term "anthropic" turns out to be rather unfortunate. The "anthro-" prefix means: "man", but the basic idea can easily be generalized to cover animals, plants and machines. The human-based version of the idea seems anthropocentric to the point of being unscientific.


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