George Price: pioneer of Universal Darwinism

George Price should get considerable credit for pioneering the idea of what we now call Universal Darwinism. Here's George:

Selection has been studied mainly in genetics but of course there is much more to selection than just genetical selection. In psychology for example trial-and-error learning is simply learning by selection. In chemistry, selection operates in a recrystallisation under equilibrium conditions, with impure and irregular crystals dissolving and pure, well-formed crystals growing. In paleontology and archaeology selection especially favours stones, pottery, and teeth and greatly increases the frequency of mandibles among the bones of hominid skeletons. In linguistics selection unceasingly shapes and reshapes phonetics grammar and vocabulary. In history we see political selection in the rise of Macedonia Rome and Muscovy. Similarly economic selection in private enterprise systems causes the rise and fall of firms and products. And science itself is shaped in part by selection with experimental tests and other criteria selecting among rival hypotheses.

This is from Price's posthumously-published 1995 manuscript, "The Nature of Selection". Price went on to lament the lack of a proper theory of selection and the lack of a proper definition of selection. He compared the current state of selection theory with the state of information theory in 1922. Price died in 1975 and apparently this paper was written in 1971 - which makes it ahead of its time indeed. Extensive quotes from "The Nature of Selection" are available free online - in the paper George Price's Contributions to Evolutionary Genetics.

While things have moved on a bit since 1970s the theory of selection is still little known. Evolutionary theory should cover it - but hardly anyone seems to realize that the theory applies to physical systems like crystals in the way that Price clearly indicated. Evolutionary theory is still in an immature state, where it isn't applied through much of its rightful domain. Progress is pretty treacle like: Darwinism has a pretty huge inertia. Also there are fragmented areas of science that are part of the study of selection that are scattered all over the place. Observation selection seems to be studied mostly by physicists and links to evolutionary theory are mostly ignored. Selection bias and sampling effects are concepts which are widely used in science - but again, these topics are rarely seen as being in the domain of evolutionary theory.

Parent-offspring asymmetry

In evolutionary processes, sometimes parents and offspring are indistinguishable and other times, they are very different.

Newborn human offspring are very different from their parents. They are much smaller and more helpless. By contrast, bacteria generally reproduce via binary fission - and parent and offspring are identical. DNA molecules produce offspring DNA molecules where it makes no sense to ask which molecule is the parent and which is the offspring.

In cultural evolution we also have a mixture of parent-offspring symmetry and asymmetry. Copies of the GPL are mostly identical and they spread via cloning rather like a virus. By contrast, many complex human memeplexes undergo a developmental process within the human mind. It is usually pretty easy to distinguish between the memes in the teacher and the memes in the student: the student's memes are less mature and well developed.

I think whether that newborn offspring identical to their ancestors (or not) is a reasonable classification criterion for evolutionary entities.

However, there can sometimes be some issues. For example, sometimes what seems to be a newborn which is identical to its parent can - on closer inspection have some systematic differences. FOr example, with DNA strands there is a parent-offspring relationship: the 'parent' strand is used as the template for the formation of the 'offspring' strand. However, this relationship is not obvious unless the copying process itself is witnessed. Once the copy has been made it is hard to distinguish it from the original - unless the copying fidelity involved is poor.

A similarly problematical example from the cultural realm is photocopying. A photocopy might appear to be identical to the original document. However a detailed examination will probably reveal some differences - allowing the original to be distinguished from the copy.

This issue is an imperfection in this classification scheme - but hardly a terminal one. It is useful to distinguish between organisms that develop significantly after birth from those that do not.

The reproductive resource gap

It's a commonplace observation that reproduction requires resources.

Reproduction often creates a transient, local resource depletion that decreases the chance of future reproduction in the short term. This "reproductive resource gap" is the topic of this article.

I've long known about this "resource gap". It seems to apply to many organic and cultural systems. Recently, I have been thinking about how general this principle is. It clearly doesn't apply to all creatures. For example a termite queen doesn't have a measurable reproductive gap - her reproductive system is a pretty continuous assembly line. However, for many creatures - from bacteria to elephants, there is a "reproductive gap" - where the mother has to accumulate resources after splitting and before splitting again.

Splitting typically produces offspring which are smaller than the mother. One hypothesis is that size is responsible for part of the effect - that bigger things are more likely to split than smaller things.

However, we know that - in many cases, the reverse relationship holds - i.e.: smaller things are more likely to split than bigger things are.

This is true for most organisms in the biosphere: there's a strong negative correlation between an organism's adult size and their reproductive rate. Smaller critters reproduce faster.

It's also true of very large objects. For planets and stars, smaller objects are more likely to break up than larger ones are - because the larger ones are held together more effectively by gravity.

Also, if erosion or corrosion are involved in the splitting - then these forces apply to the surface of objects - so again, small objects would be more strongly affected - because they have relatively larger surfaces.

Another perspective on the issue comes from considering a simple, common case. Some of the most common particle interactions in the universe consist of photons hitting dust particles. The photons form a a clear family tree with a few high energy photons near the root and enormous numbers of low-energy photons at the tips of the branches and a clearly-defined set of branching points - when the photons hit the dust particles and split.

In this system, the distance (or time) from one branching point to the next doesn't increase with proximity to the root. If anything, there's a tendency for collisions to be quickly followed by more collisions (if you just hit some dust there may be more things to hit nearby). This is another case where splitting tends to lead to more splitting - rather than to less splitting.

There are many other cases where splitting leads to more splitting. In a landslide, rocks that lave been stable for a long period of time might suddenly split many times in quick succession. There are many cases where splitting generates jagged edges and jagged edges result in more splitting. Beach pebbles are an example of this. Another similar case involves splitting reducing structural integrity. An egg is the stereotypical example, but similar considerations apply to many structures with membranes or skins. Breaching the outer wall leads to splitting and rapid disintegration.

At this stage a brief recap. A reproductive resource gap seems to be a pretty common feature of organic and cultural evolution - often the mother seems to need time to recharge. This applies to K-Selected creatures - and also to many r-selected ones - such as bacteria. However in many simple physical systems, there's often no reproductive resource gap. Instead, we find the opposite: splitting is likely to be followed by more splitting.

At this stage it might be tempting to conclude that the reproductive resource gap is an adaptation for managing limited resources - and that the reason simple systems don't have a resource gap is that they are degenerative systems which can't accumulate adaptations.

However, I've skipped over presenting some significant data. There are, in fact, simple physical systems that do exhibit a reproductive resource gap. One example involves raindrops in a condensation cloud. Smaller droplets have larger surface area to volume ratios - and so are more likely to be held together by surface tension. Another system involves falling ink droplets in water. The easiest way to explain this is with a video.

The video pretty clearly illustrates droplet reproduction - and a family tree of droplets.

However, there's a characteristic delay between one droplet reproduction event and the next. It is as though the falling droplets need to build up some kinetic energy before they can reproduce again.

In my opinion, these examples demonstrate that the reproductive gap is more than just an adaptation. There's a simple physics of needing to accumulate resources after splitting and before splitting again.

This is, I think, an interesting result in a poorly-studied area. Future investigations into the topic could look into how widespread this "reproductive resource gap" is in simple physical systems and what the interactions are between the simple physics of needing to accumulate resources before splitting and adaptations for resource management in organisms.

Positional inheritance and heritable fitness

One of the commonly-specified requirements for Darwinian systems is that fitness must be heritable. In other words, on average, fit offspring should be ancestral to fit descendants. Without this condition being met, adaptations can't get off the ground.

In this post, I will argue that this requirement is commonly met by many types of simple, natural systems involving positional inheritance.

The thesis here will be that macroscopic variations in resources are common - and result fairly directly in heritable fitness. If resources are very evenly distributed, then the condition that fitness is heritable would not be met. Such extremely even distribution of resources can happen if the environment is near to equilibrium, for example.

With diffusion-limited aggregation systems, the concentration of aggregating particles can be greater in some places than others. In electrical discharge systems, the potential gradients can be greater in some places than others. With propagating cracks, the medium can be more brittle in some places than others. These situations are all commonplace ones.

The existence of heritable fitness is consistent with observed adaptations in these types of systems. Drainage basins are well adapted to rapidly dissipate the potential energy in the incoming rainwater - and form similar structures to drainage systems designed by engineers. Lightning strikes take the shortest path from the cloud to the ground. Cracks seek out lines of weakness - resulting in an adaptive fit between the actual cracks and the weak points of the material.

In practice, the requirement for heritable fitness is a pretty trivial condition which is almost always met. To evolve adaptations some additional, more stringent conditions are also required. Essentially, the selection pressure needs to out-weigh the mutation pressure. If it doesn't do so, you get an error catastrophe - and no adaptations. In other words, devolution - rather than adaptive evolution.

Spend vs save

Resource allocation is best known as a key issue in project management. However, it is quite a general topic - perhaps best seen as being part of systems theory or cybernetics.

This article goes over some basics of how resource allocation theory applies to organic organisms - and then compares this with the situation in cultural realm.

Organisms can covert resources into fitness. However they face limits when doing so: too few resources and they can't even live, let alone reproduce; too many resources and the organism can't utilize them fast enough. This situation is illustrated on graph to the right:

The exact shape of this curve is species-specific - some species are better able to take advantage of resources surpluses than others. In particular, r-selected species typically go in for resource storage much less than K-selected ones do.

Environmental resources are not necessarily constantly available. Fluctuations in resource availability result in the need for resource storage. Organisms often need to divide their resources between ones used now and ones saved for later. Sometimes more resources are available than can be utilized at once. At other times, a future resource shortage is anticipated - for example due to the impending arrival of winter. For examples of storing for scarcity:

• Cacti receive water infrequently - and must store it in order to survive when it is absent from their environment;
• Hibernating mammals store energy as fat and then burn through it in the winter.

In the organic realm, resources can be stored as fat deposits, underground tubers, buried nuts, or egg albumen. In the cultural realm, we have stored resources such as batteries, canned food, reservoirs and barrels of oil.

In addition to adaptations associated with actually storing resources, there are also adaptations associated with when to store resources and when to spend them.

Thermostats make good examples of resource expenditure adaptations in the organic and cultural realms. There's a thermostat in your body - that keeps your temperature within a narrow range of values. There's another thermostat in your fridge - which does something very similar. Your building probably contains more thermostats that act to regulate the air temperature. In each case, the availability of resources is largely ignored by the thermostat.

Another important target of expenditure in both the organic and cultural realms is offspring. Surviving offspring are typically expensive - and often organisms only manage to produce one or two. This is an observation that applies broadly to organisms of many sizes - and to both the organic and cultural realms.

Evolution and inductive inference

Inductive inference refers to using knowledge to make predictions. It's the basis of the scientific method. This was once famously disputed by Karl Popper - but is now widely accepted.

Sequence prediction is a well-known type of induction problem. For example, what comes next: 3,4,7,11,? Inductive inference relies on knowledge acquisition - i.e. learning. Inductive inference is inherently fallible and probabilistic.

It is clear that evolution builds systems capable of performing inductive inference - namely animal brains. However, there's another link between evolution and induction - since both processes involve using knowledge of the past to make predictions about the future. This is perhaps not obvious, but if you think about it, every organism represents a kind of prediction about the environmental conditions it will encounter. The prediction is that the organism will encounter an environment have allows it to reproduce.

Many have linked evolution and inductive inference in this way. For example, in

Universal Darwinism

, John Campbell wrote:

The Darwinian process may be the only physical mechanism known to science capable of accumulating knowledge from experience. It performs inference and is a physical analogue of Bayesian updating.

Similarly, in Probably Approximately Correct, Leslie Valiant wrote:

To see evolution as a form of learning, we view the genome in evolution as corresponding to the hypothesis in learning.

Philosophers of science who view scientific knowledge acquisition as a form of Darwinian cultural evolution are also implicitly making the same link between Darwinian evolution and inductive inference.

So: what is the link between evolution and inductive inference? I have a couple of comments to make:

1. The claim that Darwinian evolution is a type of learning (made by Leslie Valiant in Probably Approximately Correct), isn't really right. Darwinian evolution can also produce genetic drift - which has little to do with learning. Evolution sometimes results in knowledge acquisition and successful inferences. Other times it results in progressive knowledge loss and extinction. It depends.

2. It is tempting to link fitness in evolution with scientific truth or accurate knowledge. However, this association is inferior in practically every way to linking fitness with popularity. Phlogiston and the aether are popular mistaken ideas. They are kept around to help show where not to tread. Death in evolution maps poorly on to falsification in science.

The idea that Darwinian evolution underlies most systems that perform inductive inference is important and under-appreciated. Those engaged in creating machines that perform inductive inference tend to associate Darwinism with genetic algorithms. Those are often seen as being just one tool in a large toolkit. They are generally used in those cases where the only thing you know about your solution space is a scalar quality metric. Knowledge of memetic algorithms paints a rather different picture. In fact, evolutionary algorithms are fundamental.

The evolutionary gene

The idea of an evolutionary gene dates back at least to G.C. Williams (1966) - who said:

In this book I use the term gene to mean 'that which segregates and recombines with appreciable frequency'

...and...

In evolutionary theory, a gene could be defined as any hereditary information for which there is a favorable or unfavorable selection bias equal to several or many times the rate of endogenous change

Williams clearly defined genes in information-theoretic terms, saying:

The gene is a package of information, not an object.

...and...

A gene is not a DNA molecule; it is the transcribable information coded by the molecule

I think that the idea of a gene as consisting of heritable information has stood the test of time. However, the idea that genes are defined in terms of their frequencies seems more suspect. Terms like "appreciable frequency" and "several or many times" lack scientific rigor. Presumably they were used in order to prevent entities which are too complex from having 'gene' status. However, there seems to be no compelling reason to build them into our conception of a gene. Similarly, invoking "selection bias" seems to define unfairly neutral genes out of existence. Again, this is unnecessary - and can be simply avoided.

Instead of Williams mutually-contradictory definitions, I have proposed defining a gene as:

a small section of heritable information

The definition makes no mention of DNA, nucleic acids - or of living systems. It is a fairly general term - and generality is usually a virtue in science.

Richard Dawkins was another early pioneer of informational genetics. Although he initially used the "gene" concept he eventually substituted "replicator" - suggesting that this concept was more clearly substrate neutral. However, the resulting replicator revolution has not gone very well - and many years later there's no science of replicators that can compete with genetics. I don't think we need two sciences of heredity. It seems better to improve the existing field of genetics than to attempt to create a new scientific field that competes directly with it.

It is worth noting that the common definition of evolution in terms of changes in gene frequencies depends critically on the use of the evolutionary gene. Without the evolutionary gene, the idea that evolution consists of changes in gene frequencies would exclude cultural and environmental inheritance - and would make no sense.

In modern times it has become fashionable to claim that evolution is too "gene-centric" - and pays too little attention to other forms of inheritance. For example, here is Robert Kadar:

We now know genes are sufficient but not necessary for natural selection because 1) genes are the likely product of selection and 2) genes are only one source of heredity among others. The gene-centric view of evolution is crumbling!

Such sentiments make no sense in the context of the evolutionary gene. Genes are the units of inheritance in evolution. All inheritance is mediated by genes - just as all messages can be represented by bits. Defining the term "gene" so that it is stupid and useless is not good scientific practice.

Another group of biologists study what they call "epigenetic inheritance". Again, this whole concept makes no sense in the light of the evolutionary gene. Inheritance is genetic - by definition. The term "epigenetic inheritance" is an oxymoron.

References

• Tyler, Tim (2009) Informational genetics.
• Tyler, Tim (2013) Genes are not sections of nucleic acid.
• Griffiths, P and Neumann-Held (1999) The Many Faces of the Gene.

Memetic sterilization

Culture has helped humans conquer the planet - and there are currently over seven billion humans in existence. The average effect of memes on their hosts has generally been pretty positive.

However, memes often have a remarkably negative effect on reproductive output. In what is widely known as the "demographic transition" women in more developed countries have fewer babies. Roughly, the richer the country is, the fewer babies are made. The culmination of this effect is seen in Japan - probably the most meme-rich country in the world. There, we see sub-replacement fertility and population decline.

One possible explanation for this involves r/K selection and the idea of a superstimulus. Standard r/K selection theory suggests that organisms may be adapted to respond to increased wealth with greater investments in offspring quality relative to offspring quality - more 'K' and less 'r'. It is clear that r/K selection theory explains some of the reduction in offspring number that is produced by wealth. However, the sub-replacement fertility seen in the real world is pretty clearly maladaptive. A possible explanation is that unusually high levels of wealth could result in a superstimulus and lead to the adaptive mechanism described above operating outside its normal range and malfunctioning.

There are also theories based on memetics. The idea that memes are involved is corroborated by the strong negative correlation between the number of years of education young women receive and the number of children they have. Few things stop your eggs from being fertilized as effectively as a college degree.

In theory, memes can benefit by diverting host resources away from reproduction of the host germ line and into the production of memes. The classic example of this is priests. In some denominations, priests have no children. Instead they devote their lives to spewing out a long string of memes: spreading the word. Richard Dawkins famously covered this hypothesis in The Selfish Gene, writing:

The meme for celibacy is transmitted by priests to young boys who have not yet decided what they want to do with their lives. The medium of transmission is human influence of various kinds, the spoken and written word, personal example and so on. Suppose, for the sake of argument, it happened to be the case that marriage weakened the power of a priest to influence his flock, say because it occupied a large proportion of his time and attention. This has, indeed, been advanced as an official reason for the enforcement of celibacy among priests. If this were the case, it could follow that the meme for celibacy could have greater survival value than the meme for marriage. Of course, exactly the opposite would be true for a gene for celibacy. If a priest is a survival machine for memes, celibacy is a useful attribute to build into him. Celibacy is just a minor partner in a large complex of mutually-assisting religious memes.

Specific technologies for sterilizing humans have evolved. Barrier contraceptives prevent sperm from reaching their targets. Chemical contraceptives mess up the female reproductive system, preventing conception. Abortion has become quick and easy - and there's even a "morning after pill". Evolution linked the human reproductive drive fairly strongly to the sex drive. Contraceptives break this link. Men can have sex without investing any resources in parental care. Women can have sex without going through labour and childbirth. Many men and women apparently choose to do this.

Memes whose transmission is vertical with respect to the generations of their hosts can be expected to have interests that are aligned with those of their hosts. Arguably we see such a transmission pattern with some traditional religious systems - with the Amish springing to mind as an example. However in the modern world, advances in communications technologies have led to meme transmission patterns that tend to be horizontal with respect to host generations. In such cases, we can expect to see more parasitic memes thriving - unless increased efforts are put into preventing their spread. However, in the case of contraception, the memes involved seem to be largely unopposed. It is true that some religious factions object to abortion while others discourage use of contraceptives, however overall, the fertility-reducing memes associated with "family planning" face relatively little opposition.

As an example of a sterilization meme, consider the essay Why it is important not to have children from Richard Stallman's personal site. Stallman is clearly a memetic hijacking victim. In his essay he clearly describes the competition between memes and genes and explains why he chose to propagate his memes - rather than his genes.

Memes are sterilizing humans on a massive scale. They also appear to be getting better at it. This leads to the obvious question of what the future holds. Will we see human fertility decline to the point where we see "peak human"?

I think that is the most obvious conclusion - although the supporting reasoning has relatively little to do with existing fertility trends. Instead it seems clear that the future dominant organisms will be engineered. They will, in short, be superintelligent machines. Humans might persist in such a world, but probably only as a very small piece of it. Perhaps their main role will eventually be in populating historical simulations. The machines will trace their ancestry back through us. We will be regarded as their progenitors. Human DNA will probably survive for a long time to come. However it is challenging to imagine a realistic distant future with very many "meat bag" humans in it. The current situation is just a stage the biosphere is going through before the rise of the superintelligent machines.

Parasitic hijacking

In evolutionary theory, hijacking is an extreme form of manipulation in which one agent winds up performing actions that mostly benefit some other agent.

In order to perform a successful manipulation, the manipulating agent often has to be a close symbiont - in other words, a parasite.

To successfully manipulate its host, the nervous system is an attractive target. mind parasites. It is still possible to manipulate the host without invading their nervous system - and many parasites succeed by other techniques. They might synthesize hormones or neurotransmitters - or maybe make their hosts cough, sneeze or itch. However, these approaches don't really qualify as hijacking. One of the defining characteristic of a hijacking is that the hijacker directs many of the hijackee's actions.

The hijacking metaphor makes the most sense in the context of Richard Dawkins' characterization of the host's phenotype as being a vehicle. A parasitic hijacker may then hijack the host's vehicle and use it to its own ends.

Sometimes the victim's higher mental faculties are compromised during the hijacking - in which case the victim is often referred to as being a "zombie".

Hijacking parasites may be either organic or cultural. Memetic hijacking is a well-known phenomenon. Memetic hijacking illustrates the precise targeting that's available to cultural software. The host's motivational system can be reprogrammed to the point where they want nothing more that the success of the memeplex they are infected with. In some cases, the hosts are even sterilized by their memes - ensuring that resources that might otherwise be invested in childcare are directed into meme propagation.

David Sloane Wilson on cultural kin selection

David Sloane Wilson has weighed in on cultural kin selection. It seems as though he's saying that he doesn't understand how it works - and is hoping others will explain it to him. The good news is that I've already published dozens of articles on the topic that explain it from a wide range of angles.

David's article suggests that his problem is that cooperative cultural interactions take place between organisms which "lack genetic relatedness, genealogical or otherwise". This seems like a basic point that is very easy to explain. Much cultural cooperation is based on shared memes. When two individuals have the same money, the same language or the same religion, they are more likely to cooperate. The more shared memes they have, the more likely they are to cooperate (on average). The idea of cultural kin selection is based on cultural evolution, kin selection acting on memes (rather than DNA genes) and symbiology and manipulation.

David says large spatial and temporal scales are part of the problem. I don't understand this problem. Consider the US dollar for example. This exists in billions of identical copies - and produces a lot of cooperation - which is all well explained by cultural kin selection - since the dollar bills are close relatives with r~=1 - and they clearly influence manipulate their hosts. The dollar's reach is global and it has lasted for quite a long time. It is not clear what the supposed problem with large spatial and temporal scales is.

To reiterate some by-now tired points, kin selection emphasizes close relatedness - where the process actually produces adaptations - such as the human breast. Group selection de-emphasizes relatedness. As a result advocates apply it to groups consisting largely of non-relatives - such as entire tribes - where theory predicts that the process is largely ineffective. As a result group selection has a long (and ongoing) association with junk science.

Mixing cultural evolution and group selection is a recipe for confusion. That's the very last thing the important science of cultural evolution needs. Mixing the two is not helping to educate the public, it seems more like a controversy-based marketing strategy. To me it looks like self-promotion at the expense of misinformation.

To reiterate, it is not the case that group selection explains cultural dynamics that kin selection does not. Group selection enthusiasts have spent decades looking for such cases. They have failed - and now most of them have given up. I thought David Sloane Wilson was among those who had publicly thrown in the towel - and given up this quest. This article suggests that the old group selection dream of finding new science and making original predictions still lives on. That does not seem like a good thing.