Mark Pagel: Human evolution's creative drive

A 2013 interview with Mark:

Joe Henrich: The Secret of Our Success

Here's a 4 minute promotional video for Joe Henrich's recent book on cultural evolution, "The Secret of Our Success":

Cultural recapitulation theory

Recapitulation theory refers to the idea that organism development recapitulates evolutionary history. As Ernst Haeckel's put it, "ontogeny recapitulates phylogeny". Most biologists would describe Haeckel's ideas as being widely discredited. The story of Haeckel doctoring his embryo illustrations to support recapitulation theory has been widely retold.

Recapitulation theory encapsulates a rather simple truth - that development often proceeds by strapping on extra developmental phases. When this happens, ontogeny does indeed recapitulate phylogeny.

The brain makes a simple example. Brains are divided into layers, and over evolutionary time, more layers have been added.The human neocortex, for example consists of six layers. During development the neural layers are formed progressively. Migrating neurons climb up a scaffolding made of radial glial cells and bypass previous layers of neurons in the cerebral cortex, creating a new layer on top of their predecessors. This mirrors development over evolutionary time - where ancestors had fewer layers of neurons.

A simple, pure example of cultural recapitulation theory can be found in knot theory. Knots are often formed by tying knows on top of other knots. The simpler knots come first historically as well as during knot construction. A reef knot is a simple example of one knot being tied on top of another knot in order to strengthen it.

The concept of "cultural recapitulation" is often used in another way. Some say that the way that individual learning mirrors historical discovery is a case of cultural recapitulation. For example, the order in which scientific concepts are taught to children might mirror the order in which they are discovered. This is certainly recapitulation and it does involve culture, but the analogy with Ernst Haeckel's idea is weaker than with the knot example I gave. The reason is that the development involved is the development of a young animal - a memetic host rather than a memetic product. The corresponding biological analogy would be if the way in which organisms were infected with pathogens reflect the sequence in which those pathogens evolved. If is easy to imagine reasons why that might be true - for example new pathogens might be less expert at spreading to new hosts. However, this seems a bit different to classical recapitulation theory - since that does not normally involve symbiosis.

Will cultural recapitulation theory suffer the same fate as its organic counterpart? It is, perhaps too early to tell. However, maybe cultural recapitulation theory will help to revitalize recapitulation theory in the organic domain. It is a bit of a shame that recapitulation theory is so widely labelled as a dud idea. Perhaps cultural examples will help to illuminate the truth at the core of the idea.

Towards a Science of Culture within a Darwinian Evolutionary Framework

There is a series of videos dating from June 2015 with this title:

• Alex Mesoudi;
• Eva Jablonka;
• Arnon Lotem;
• Amotz Zahavi;
• Arie Altman;

Alex goes first, the other scientists reply and respond and then Alex responds at the end. There's also a playlist.

The continuing rise of the "meme" meme

In 2011, I declared 2011 to be the year of the meme - showing graphs of the "meme" meme over time as evidence.

Later, in my 2011 book on memetics I published a graph showing the explosive growth of the "meme" meme over time.

Rounding off 2015 seems like an appropriate moment to revisit these graphs. Here are up-to-date versions:

History of "Meme" searches (with news information)

History of "Memes" searches (with news information)

The spectacular growth of the "meme" meme has continued. The term "meme" has long eclipsed the term "gene" on the internet - a sign of the coming memetic takeover. The popularity of the term "meme" bodes well for the future of memetics, I think.

The virtues of intelligent design

Intelligent design creationism is famously opposed by evolutionists. However, few criticize the idea of intelligent design by humans. I think it is normally taken for grated that engineers have brains and so can intelligently design things.

Enter Matt Ridley. Matt characterizes intelligent design by humans as a form of creationism, and recently wrote a whole book, The Evolution of Everything, documenting its failures. Economies, religions, politics, companies and governments are all places where Matt sees this "creationism" - and its poor performance. I don't remember a single positive comment about intelligent design in the whole book.

As an antidote, I feel inclined to offer a brief summary of why intelligent design by humans is a useful tool. This didn't make it into my review - but I'm putting it here instead.

One of the tools of intelligent design is virtual prototyping. This involves constructing models in a virtual world and evaluating them there. This results in a rapid build-test cycle, low construction costs, and failures which are inexpensive.

A common construction technique among engineers is known as "rapid prototyping". This typically involves building and testing small models before constructing the final object. The virtual prototyping that takes place in the minds of intelligent agents is very similar to this "rapid prototyping" - and it has many of the same benefits associated with it.

Intelligent design is a form of evolution in which mutation and merging operations take place within a single mind. This rich environment permits a wider range of mutation and merging operations. The recombination operations include interpolation and extrapolation. This, ultimately, results in enhanced evolutionary dynamics: faster evolution and better ability to avoid getting stuck on local optima.

Intelligent design by humans does have some problems and limitations. In particular, human minds are small, have little storage. They are irrational and difficult to program. The virtual worlds they simulate are sometimes unrealistic and sometimes delusional.

However, rather than lamenting these problems, we can work on them. We can work on building bigger, better, faster minds, with access to more memory, and greater skills at performing inductive inference. Rather than relinquishing intelligent design as Ridley recommends we can improve it - using machine intelligence.

My review of The Evolution of Everything is up

My review of The Evolution of Everything is up. It is titled: "A demonization of intelligent design". Check it out.

Rather to my surprise, I found quite a bit to disagree with in Matt's book. In my humble opinion, the basic problem is that Matt didn't take on the ideas described in Keeping Darwin in Mind. This leads him to regard intelligent design by human designers as a form of creationism - making it a foe to be vanquished. I don't think that this is a very well-balanced perspective.

I have long thought that the idea of incorporating intelligent design into Darwinism might cause some people to choke. So far, to the best of my knowledge, only Matt Ridley and Daniel Dennett seem to have got into problems in this area. Ridley seems to be having more problems than Dennett did.

If you liked this one, feel free to check out my other book reviews.

The teaching first hypothesis

Most accounts of the origin of human cultural evolution focus on imitation or social learning. However there's another possibility - that the most relevant changes were in teaching ability - or inclination to teach.

The scenario I favor relating to the origin of social learning in humans involves walking. This scenario is described in my essay walking made us human. Walking is a socially-transmitted trait. Learning it promptly is extremely important for modern humans. Walking is also widely taught to offspring by their parents. This observation suggests another scenario for the early cultural evolution of humans - in which changes in teaching ability are more significant than changes in learning ability.

Teaching ability is easier to change via cultural evolution than infant learning ability is. It is probably easier to change via DNA gene evolution too. Since the trait looks as though it is probably easier to modify, there's at least a fair chance that the main difference between the early walkers and the non-walkers was that the walkers put more effort into teaching their offspring.

Teaching is not involved in all types of cultural transmission. However it is involved in transmission of walking. Acceptance of the scenario described in Walking made us human makes this "teaching first" hypothesis more likely.

The focus on learning seems fairly ubiquitous among students of cultural evolution to me. Susan Blackmore in The Meme Machine promoted the importance of imitation. Lee Alan Dugatkin reviewed Susan's book and then went on to write The Imitation Factor. While both books are excellent, if the teaching first hypothesis is correct then an emphasis on imitation may be misplaced.

Can we test the idea? The detailed history is probably lost in he mists of time. However, we can probably test the idea that teaching ability is easier for cultural and genetic evolution to produce. If so, the teaching first hypothesis becomes favored by Occam's razor - conditional on the ideas described in walking made us human.

More meme denialism

There are still a lot of people who are totally confused about cultural evolution. Whether due to ignorance, stupidity, bad teaching, or whatever, there are still lots of people who just don't get it. They are still on the wrong side of the meme paradigm shift.

We can say these people lack meme literacy. Or we can describe them as being meme challenged. However, sometimes, a bit more of a verbal kick in the ass seems desirable. If people are particularly ignorant of the literature, seem to think they are entitled to spout nonsense on the topic, and fail to update on evidence, the term 'meme denialism' may be appropriate.

I think the term should be reserved for the worst offenders. So, I'm thinking that Steven Pinker and Massimo Pigliucci are in denial about memes, while Peter Richerson and Rob Boyd are more in the 'minor misunderstandings' zone.

When Helena Cronin says:

There's culture; there's history; there's change; there's progress; there's technological innovation; there's growth of knowledge; there's social learning; and there's lots more. But there's no cultural evolution.

That's a nice example of what I'm talking about: complete denial of the whole field of study.

Another example comes from John Gray, writing:

There is no general theory of evolution.

Another case is Jonathan Marks (2000):

Now unlike genes, memes have the decided disadvantage of not actually existing.

This is what meme denialism looks like.

Update: I previously wrote about meme denialism here.

Matt Ridley: How New Ideas Emerge

The blurb says: "Streamed live on Dec 3, 2015". You may want to fast-forwards to get to Matt's talk.

One notable moment is where Matt receives an audience question about whether his ideas are falsifiable at around 1:20:00. Note that the YouTube user involved edited and re-uploaded the video after I watched it - so you may find that the relevant section of the Q&A session has been moved or is missing.

Matt was also interviewed recently by CNBC's Rick Santelli here.

Matt answers questions about The Evolution of the USA here.

Creative destruction

It is easier to destroy than it is to create. If similar efforts expended on creation and destruction, the destructive change is often are bigger - sometimes much bigger. So: those who seek leverage should seriously consider destruction as an option.

I've written about the possibility of positive destruction - in my 2010 positive destruction article.

In the context of cultural evolution, creative destruction typically involves destroying memes, preferably bad memes.

This is partly the job of promoters of skepticism and rationality. As an example, both Dawkins and Dennett have had a go at sabotaging religious memes. I have often expressed puzzlement at this behaviour - since religious though has been widely discredited by scientists. Scientists attacking Abrahamic religions in modern times look a bit strange - since those religions have not been scientifically credible for a long time now. Scientifically, they are a dead issue. However, maybe, by taking advantage of the power of destruction, they are still doing some good.

I identified some other bad causes in my 2010 'bad causes' video. However, I didn't really link my conclusions up with those of the positive destruction essay. Top of my list at the time was climate change. Reviewing the topic five years later, climate change is still my number one bad cause. I don't think I have ever seen so many resources and time frittered away on such a worthless and ineffectual cause. Experts on cause prioritization seem to fairly uniformly agree that climate change is not a high priority. How then to explain the wasted billions?

One of the most obvious explanations is that fear sells. Global warming alarmists are fear-mongering. I also think that virtue signaling explains a lot about the irrational global warming hysteria. The cause offers people a chance to save the world - a well-known superstimulus to do-gooders. Trying to save the world shows that you care a lot.

Maybe global warming alarmism has enough detractors for it to no longer be low hanging fruit for critics. However it is still pretty fat - and fat targets are often attractive.

If so, the efforts of Matt Ridley and Bjorn Lomborg (among others) may prove to have been especially welcome.

I am especially disappointed with the role that many scientists have played in the fiasco. Like Matt Ridley, I see the climate wars especially indicative of scientific funding bias. Ridley explains the problem in What the climate wars did to science. Scientists should be the first to speak up in a situation like this. A few scientists have done this = but overall, this is not what we have seen. It is a big embarrassment to those who want to proudly call themselves scientists.

Nemes

There are only twenty six letters in the English alphabet. There are also many more types of copied entity than are dreamed of in dual inheritance theory. It follows that those who would continue with terminology along the lines of genes and memes should choose their letters carefully.

I've previously - rather half-heartedly - proposed that we use lemes for learned entities. 'Lemes' cover individual and social learning (by contrast to memes which are normally defined in such a way that they are confined to social learning.

Another proposal which covers similar ground is 'nemes'. The 'n' is short for 'nervous' or 'neural'.

Paul Gilchrist proposed the term 'neme' in 2014 here and here.

A good thing about 'neme' is that it is potentially more inclusive. Not all copying within brains is learning. For example, some is forecasting based on existing models. 'Neme' could plausibly be used as an umbrella term that covers all within-brain copying.

A bad thing about 'neme' is that it is rather closely associated with wetware. Computers also have individual and social learning. However, it seems like quite a stretch to apply the terms 'nervous' or 'neural' to computers.

Another problem is that Paul Gilchrist and I don't seem to agree on what the term should mean. I would want to expand the term to cover copying inside computers and copying of high level structures inside brains - such as ideas. By contrast, Paul says:

I use the term neme to apply to the nerve impulse that is the fundamental element in the operation of the nervous system.

I see where Paul is coming from - but then we need more names to cover all that other stuff that goes on inside brains. We do have 26 letters - but we should use them sparingly and make sure that we don't squander them.

Overall, I quite like the 'neme' term. The surrounding definitional debates show that it needs some more work, though.

Evolutionary frameworks

Some say evolution is a theory, others say it is a fact. I tend to regard evolution as a framework. It is OK to regard evolution as a theory - but as theories go, evolution has a lot of holes in it. On its own, evolutionary theory doesn't make all that many predictions. It is largely reliant on other theories to help it to make useful predictions.

It's possible to make a map of the holes in evolutionary theory - to see where other theories can be attached in order to provide support. That's the main function of this post.

The biggest hole in vanilla evolutionary theory is that it generally lacks a predictive theory explaining which creatures are fitter. For birds, the additional theories of aerodynamics are required; for bats, a theory of echolocation is needed - and so on. These other theories are more closely associated with developmental biology than they are with evolutionary theory. In general, additional theories that map from genomes to expected fitnesses are required.

Evolutionary theory includes or interfaces to genetics. Genetics also has some holes - or at least permits other modular theories to be attached to it. Genetics needs theories of mutation, merging and error correction. There are various types of mutation: point mutations, frameshift mutations, insertions, deletions and so on; mutational theories describe what can happen, when it can happen and how likely it is to happen. "Merging" theories cover recombination, symbiosis and rarer cases where genomes fuse or assimilate each other. A full theory theory must deal with mate selection - and the choice of symbiotic partners - since these factors determine which genomes merge. Error correction theories affect both mutation and merging. Genome modifications are post-processed by error detection and correction processes. These bias the results of these processes. Some modifications are permitted, others are rejected, and others are modified further. Error correction results in an adaptive bias to mutations - since the most deleterious mutations are selected against the most strongly by these mechanisms.

Some of the more vocal proponents of the basic idea in this post - that evolutionary theory contains holes - are Geoffrey Hodgson and Thorbjørn Knudsen. For example, in the paper: Why we need a generalized Darwinism, and why generalized Darwinism is not enough, these authors explain how evolutionary theories do not stand alone and depend on other bodies of knowledge. I agree with their perspective on this issue.

Hodgson's habits and routines

In 2003, Geoffrey Hodgson proposed that we use the terms "habit" and "routine" as replacements for the term "meme". As with most other meme synonyms, this suggestion doesn't seem to have been very popular. Retrospectively, it appears to me that this proposal has critical technical limitations that put it out of the running.

Hodgson says that "habits" represent individual transmission while "routines" represent group-level transmission. The dictionary seems to think that individuals can have routines as well, muddying this proposed distinction. Hodgson defends the idea that these entities can act as units of cultural transmission. What he fails to defend is the idea that all cultural transmission is mediated by habits or routines. This claim seems straightforwardly incorrect. For example, the Bible is a bunch of memes, but it isn't a bunch of habits. Habits are associated with individuals, but no individual counts the bible as being among their habits. Nor is the bible a bunch of routines.

This makes Hodgson's proposal incomplete basis of a theory of cultural evolution. If adopting his terminology, we would need one theory for the evolution of habits and routines, and another theory for the evolution of other aspects of culture. Or we would need to redefine these terms and give them counter-intuitive technical meanings. Can we patch up Hodgson's proposal by finding another term (apart from 'habits' and 'routines') to represent other inherited aspects of culture? Maybe - but it looks like a dustbin category to me.

The other issue with Hodgson's proposal is that "habits" and "routines" are not necessarily socially transmitted. We already have terms for mental content that isn't necessarily socially transmitted: 'ideas' and 'concepts'. Part of the reason that term 'meme' found its niche is that it expressed a different idea from the terms 'idea' and 'concept'. If 'meme' had been another synonym for 'idea' and 'concept', it would have failed.

I think Hodgson's proposal is now dead. This post is a post-mortem that attempts to explain where it went wrong.

Darwin meets Turing

A cryptic title - but this post is about applying models of universal computation to universal Darwinism.

Most versions of universal Darwinism agree that evolutionary theory applies to brains and thinking. This idea was pioneered by B. F. Skinner and D. T. Campbell and promoted by W. H. Calvin, G. Cziko and G. Eldeman among others. Evolutionary theory explains all goodness of fit and all knowledge gain.

If evolution explains the operation of brains, it ought also to explain the operation of computers - since both are general purpose input-transformation-output learning systems. We have some nice, simple models of computation. Can universal computation illuminate Universal Darwinism? In this post we will find out.

We will use the NAND gate + interconnect model of parallel computation and see how it relates to evolutionary models. Copying is a primitive operation in Darwinism: in NAND land it corresponds to signal branching. Selection is another primitive operation in Darwinism: in NAND land, it corresponds to signal termination. That just leaves the NAND gate itself. The NAND gate takes two inputs and produces one output. There are two ways of looking at the NAND operation from a Darwinian perspective. One is as a conditional selection operation. A NAND gate obliterates or inverts one of its inputs depending on the value of the other one. The other way is as a merging or joining operation between two signals. That completes the relationship between these two models.

What did we learn from this exercise? Merging or joining operations turned out to be fundamental. Mutation was not fundamental. It turns out that you can model mutations using copying, selection and merging - if necessary.

Intuitively, the products of evolution include brains - so it is not surprising that some models of evolution are capable of computing partial recursive functions.

However, a universal model has some negative aspects. There's a sense in which universal models are capable of producing any output - and notoriously, models which predict everything are not very useful. We can take some consolation in the idea that there can be all kinds of differences between different universal systems - they differ in speed, degree of parallelism, memory to compute ratio, relative component costs, brittleness, support for synchronous operation - and so on.

One thing I learned from building this model is that my usual reply to critics who allege some Darwinian models lack predictive power is not completely satisfactory. I usually say that constraining the scope of the mutation operator is enough to limit the resulting predictions. However, if there's a recombination operator, that can also lead to universality - and produce a model that is compatible with a lot of observations. It looks as though mutation and recombination both need limiting.

This post presents a model on the level of the bit. Another way of building evolutionary models of computational processes is to rise above the level of the bit. Conventionally, most mutation and recombination takes place between genes - rather than bits - and genes are conventionally quite a bit bigger than bits. This path produces a range of interesting models which have already been well explored in some detail by genetic algorithm and genetic programming enthusiasts.

Future fertility

I think that most models of the demographic transition have human fertility continuing to fall globally - for some time to come. Recently I read a prediction - posted by Jason Collins - that fertility would rise. Here is Jason's post linking to his article: Fertility is going to go up.

I am pretty sceptical. At one point Jason confesses that he might be wrong, writing:

I’m the first to admit we could be wrong in the prediction of a fertility increase. What other shocks are still to come? Will the continually changing environment drown out the underlying evolutionary dynamics? Our instinct is that most of the shocks that can affect fertility have played out in the developed world – increased incomes, effective contraception, female choice and so on. But what further shocks could reduce fertility?

Here's my attempt at a list of the big fertility-reducing factors that currently still lie largely in the future:

• More engaging games;
• More engaging pornography;
• Sex with robots;
• Economic competition with machines;
• Chemically-induced orgasms;

Basically, memes have run rings around genes, reducing human fertility. IMO, this process shows no sign of stopping - or even slowing down. The argument that parasites rarely kill their hosts doesn't help much here - parasites can kill their hosts if they have multiple host types and aren't dependent on one particular host type. That will be the situation with intelligent machines - memes won't be dependent on human hosts any more - so they won't be forced to keep them around.

Overall, based on our current understanding of cultural evolution, it seems quite reasonable to model future human fertility as falling to zero. Fertility is going to go down. Jason's argument for the opposite conclusion seems to be based on DNA evolution. However, this is slow - by comparison with cultural evolution. You have to model cultural evolution to have much hope of predicting future changes.

Genotype, phenotype - what's the problem?

Part of the muddle still surrounding cultural evolution involves the issue of how to make the genotype/phenotype distinction in the cultural realm.

In the organic realm, this distinction is foundational in genetics, dividing an organism's heritable information from its products. The distinction defines the domain of genetics.

Various authors have written on this issue - including Peter Turchin, Susan Blackmore, Bill Benzoin, Alberto Acerbi and Alex Mesoudi.

Here's what it says about the genotype–phenotype split on Wikipedia:

The genotype–phenotype distinction is drawn in genetics. "Genotype" is an organism's full hereditary information. "Phenotype" is an organism's actual observed properties, such as morphology, development, or behavior. This distinction is fundamental in the study of inheritance of traits and their evolution.

Wikipedia has it right. To me, this seems simple, clear and applies equally well to both the organic and cultural realms. I've been applying this distinction consistently from the beginning - and it works well in cultural evolution.

I can't help but see the position of others on this topic as being muddled and confused. This post raises the question of why this confusion exists. For me, this seems like cultural evolution 101. The genotype/phenotype distinction is a basic issue that people ought to be able to grasp fairly easily. Yet it doesn't seem to be the case. Why are so many researchers in such a muddle?

Perhaps one of the better resources on this issue is Peter Turchin's posts on the topic. They are a bit of a brain dump and illustrate his thought processes at work. However, it does seem to me that most of these authors don't seem to have considered the issue very carefully. For one thing, many of them don't seem to understand why the distinction is important, and apparently think they can get along OK without it. I think this probably indicates a weak background in evolutionary thinking.

Perhaps one problem is that academics often try to get by without the concepts of cultural organisms or cultural creatures. They try to shoehorn everything into the host's genotype and phenotype. If that's the cause of the problem, this issue is just another nail in the coffin of the extended genotype and the host-centric approach to cultural evolution.

• Turchin: What’s Cultural Genotype?
• Turchin: More on Cultural Genotypes
• Acerbi & Mesoudi: If we are all cultural Darwinians what’s the fuss about? Clarifying recent disagreements in the field of cultural evolution
• Blackmore: The meme machine -Error on BB import

Observation selection effects misunderstood

I argue in my observation of the observable video that observation selection effects are part of evolutionary theory - and are simply the result of applying selection theory to observers. I notice that not everyone seems to be on the same page as me about this. Both John Campbell and Matt Ridley have recently ridiculed anthropic reasoning. In chapter one of The Evolution Of Everything, Matt Ridley compares the anthropic principle to a 'skyhook' and writes:

anybody outside a small clique of astronomers who had spent too long with their telescopes, the idea of the anthropic principle was either banal or balmy, depending on how seriously you take it. It so obviously confuses cause and effect. Life is adapted to the laws of physics, not visa versa.

John Campbell doesn't like observation selection effects either. Here are my comments on his treatment in Darwin does Physics, from my book review of it:

I agreed with John in most places - but there were a few areas of disagreement. One was the treatment of observation selection effects. I regard these as a key area where the usefulness of selection is already appreciated by physicists. "Observation of the observable" neatly generalizes Spencer's "Survival of the fittest". However, John's perspective is very different. He says that the anthropic principle is anthropocentric and criticises observation selection as being tautological and unscientific. It is true that the term "anthropic" has an anthropocentric name. However, I think that it is best to ignore the use of this stupid terminology and focus on observation selection effects. These are not tautological or unscientific. Indeed, they help support the case for the applicability of Darwinism to physics - since these selection effects are already well recognised by physicists as a source of 'goodness of fit' between physical law and humans. John has no coverage of this in his book - it seems like a fairly major omission to me.

Both Ridley and Campbell quote from the puddle parable of Douglas Adams to support their ideas. Douglas wrote:

Imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!

Douglas is arguing that reasoning from apparent design to the existence of a creator is not sensible. However this isn't an argument against the utility of observation selection effects! Campbell and Ridley both need to rethink their positions.

All inheritance is genetic inheritance

One of the dodgy memes perpetuated by some cultural evolution enthusiasts is that there is more to inheritance than genes. Boyd and Richerson say that human evolution progressed "not by genes alone". Lee Alan Dugatkin calls imitation "evolution beyond the gene". Jablonka and Lamb say that "Genetic" is only one of four dimensions of variation, the others being the "Epigenetic", "Behavioral" and "Symbolic" dimensions. Steven Rose says there is "life beyond the gene". David Sloane Wilson says:

core evolutionary theory needs to expand beyond genetics to include other inheritance systems, such as environmentally induced changes in gene expression (epigenetics), mechanisms of social learning found in many species, and the human capacity for symbolic thought that results in an almost unlimited variety of cognitive constructions, each motivating a suite of behaviors subject to selection (Jablonka & Lamb 2006; Penn et al. 2008).

Expand evolutionary theory without expanding genetics? It makes no sense to me: science needs an expanded genetics too. Expanding the domain of evolutionary theory without expanding the domain of genetics would be a very lop-sided approach.

Memetics pioneered the expansion of genetics to cultural evolution way back in the the 1980s. Efforts to establish a new science of 'replicators' to compete with genetics have gone nowhere - and don't make much sense. The latest attempt to establish a science of non-genetic inheritance - epigenetics - is an absolute joke. What a "dustbin" category that is. It is good for one thing - being an example of how not to do science. Waddington's excellent notion of epigenetics is in the process of being hijacked by foolish and ignorant scientific punks. What we need is a generalized gene and a generalized genetics. When generalizing evolution, scientists should not neglect to generalize genes and genetics! These concepts are absolutely needed for any sensible grounding of evolutionary theory on information theory. Genes should be the units of heredity and genetics should be the study of heredity.

Some say that genetic algorithms are not really "genetic". It is nonsense: genetic algorithms really are genetic. Take genes and genetics seriously, dammit. Don't confine them to the special theory of evolution - that's not where they belong.

Molecular biologists may have appropriated the term "gene" - but it isn't theirs to define. As Steven Pinker puts it:

Molecular biologists have appropriated the term "gene" to refer to stretches of DNA that code for a protein. Unfortunately, this sense differs from the one used in population genetics, behavioral genetics, and evolutionary theory, namely any information carrier that is transmissible across generations and has sustained effects on the phenotype.

If we don't expand genetics now, it will only need doing later. Cultural evolution's scientific lag in academia is large, but forward thinking individuals should still be able to see that the need to generalize genetics is now clear and obvious.

IMO, Boyd, Richerson, Dugatkin, Jablonka and Wilson are not doing scientific progress any favours by dragging their feet on this issue. Get with the program, folks. The 'beyond the gene' meme might look progressive to you - but it looks backwards to me. The best way forwards is to generalize genes and genetics when generalizing evolution. This is scientific evolution, rather than scientific revolution - and evolution is usually less painful and more likely.

Don't tell me that genes and genetics have more inertia and are harder to move. That much is now obvious. The point is that they need to move, and will have to move eventually. So, who is helping? ...and who is not? Which side of this issue are you on?

Matt Ridley: Cato institute 2015

This one is from November 11th (two days ago). Ridley speaks for the first half, with Ronald Bailey taking over after half an hour.

Matt mentions the "Special" and "General" theories of evolution a few minutes in.

Matt irritates me by repeats]ing an old and ignorant objection to memes by anthropologists. He says (21 minutes in):

You don't have to have particulate information which is what people used to think about cultural evolution that the problem was that you don't have something equivalent to a gene which is a sort of specific, hard object.

The main problem here is the idea that genes are "specific, hard objects". In informational genetics, genes are informational. They can exist in databases just as well as cells. My article: Genes are not sections of nucleic-acid goes into more detail.

I feel that the idea that our understanding of cultural evolution has progressed from the idea that culture consisted of "specific, hard objects" to a less "particulate" understanding is a fantasy view of the history of the field which misunderstands and then denigrates the meme enthusiasts.

Memetics is often reductionist - in that it splits cultural inheritance into "bits" of culture. This reductionism is highly productive: a foundational technique in science is splitting complex things into smaller pieces in order to analyse and understand them.

The evolution I would like to see is in people's understanding of genes. Either genes are units of inheritance, or else we need a whole new science of heredity to replace genetics. Keeping genes as units of inheritance is the more conservative and sensible path, I claim. The idea that genes and genetics are confined to the "special theory of evolution" is an awful one. Genetics could be - and should be - quite general. My next post will be all about that topic.

Narrow memetics

When I got involved with memetics I think that people had previously used the term "memetics" to refer to the study of memes. It was more-or-less a synonym for "cultural evolution".

One of the concrete proposals I made was that the split between genetics and evolutionary theory be extended to cultural evolution - with memetics mostly studying how memes mutate and recombine. Since most of the differences between organic and cultural realms lie in the area, there needs to be a bit of a split between memetics and genetics - whereas most of the other the areas of evolutionary theory apply to both domains.

I started promoting the idea that the split between evolution and genetics should be extended into the cultural domain seriously in 2013 - with articles like these:

• Cultural evolution vs memetics

• Memetics: ahead of its time

The idea was partly intended as a marketing move for memetics. Academia has largely opted for the term 'cultural evolution'. However, according to this terminological scheme, most of the actual differences between the dynamics of the organic and cultural realms lie in the genetics/memetics divide. Memetic mutations and recombination take place inside brains - rather than inside cells - and so there are expanded opportunities for more complex dynamics. Most of the alleged difference between the dynamics of the organic and cultural realms are either differences between memetics and genetics, fairly direct consequences of those differences, or are not really differences at all - once symbiology has been properly taken into account. Differences that turn out to be insignificant include Lamarckian inheritance, degree of reticulation, directed mutations and intelligent selection.

This narrative also helps to make sense of the delayed adoption of memetics. In the organic realm evolutionary theory was discovered in the 1800s, while genetics didn't really have its own departments until the 1930s. Assuming that the study of cultural evolution lags behind the study of evolution in the organic realm would predict that memetics will similarly lag behind the study of cultural evolution - an observation that seems to accord well with the facts.

Another thing I use this narrow version of memetics for is to disarm critics. For example, critics sometimes assert that memetics doesn't explain do a good job of predicting why some memes are fitter than other ones. I sometimes reply to this that this isn't the job of memetics - any more than it is the job of genetics to explain why some genes are fitter than other ones. Just as genetics studies mutation and recombination, so memetics should study cultural mutation and recombination. Explaining why one bird's wing works better than another one would be a job for an aeronautical expert - not a geneticist. Similarly a memeticist can reasonably respond that the reason why one bunch of aeroplane memes has won over another bunch of aeroplane memes isn't really part of their field of study. It should be added that some expanded versions of memetics do get into this topic. Applied memetics, population memetics and memetic engineering spring to mind as memetics-related areas that actually do make predictions concerning meme fitnesses.

Currently I think of the narrow version of memetics described in this post as being one of my innovations in the field. However expanding the meme/gene split into a memetics/genetics split seems like a rather obvious idea - and I might not be the first one to take it seriously. In which case my role will have been to popularize the idea.

I don't have much feedback about the merits of this 'narrow' version of memetics. Is it the future of memetics? Or is it a cut-down version of the original vision that just irritates other practitioners?

References

• Tyler, Tim (2013) Cultural evolution vs memetics
• Tyler, Tim (2013) Cultural evolution's scientific lag
• Tyler, Tim (2013) Memetics: ahead of its time

Sylvain Magne: information vs codes

This article is a brief commentary on Sylvain Magne's recent article "Objections to Daniel Dennett's informational meme".

Like Dennett, I endorse informational memes. However, Dennett has his own conception of 'information' which differs from that of Shannon. Dennett claims - rather curiously - that there's often no identifiable Shannon channel associated with much hereditary transmission. By contrast, I simply defer to Shannon/Weaver information theory when it comes to the definition of "information". If I want an observer-neutral concept, I simply specify a reference observer.

Sylvain's article rejects the memes-as-information position and proposes Sylvain replace it with memes-as-codes.

I didn't get on with Sylvain's article at all. I have a broader conception of "information" that the one in the paper, and a narrower conception of what constitutes a "code". The term "code" doesn't really have a strict technical definition - but for me a "code" is a collection of symbols - where a "symbol" is something that stands for something else. With the term "code" there's also a pretty strong implication of a symbol-to-symbol mapping. I don't like Sylvain's idea that 'code' is a synonym for 'pattern'. That conflicts too much with common usage. My objection to memes-as-codes is the same as the one Sylvain attributes to a Dennett email in his paper: not all culturally-transmitted phenomena consists of symbols. For example, a wheel is not composed of symbols.

As for my broader conception of "information" - in my defense, my use of the term is the standard one used in information theory used by scientists and engineers everywhere. This is absolutely applicable to heredity - no matter what Daniel Dennett and many other philosophers of biology seem to think.

I point out that academic students of cultural evolution also frequently define their cultural variants in terms of "information". Boyd and Richerson have been doing this pretty consistently since 1985, for example. In fact they even define 'culture' in terms of information. Here's what they said in 1985:

Culture is information capable of affecting individual's phenotypes which they acquire from other conspecifics by teaching or imitation

These days, we would not confine culture to conspecifics or cultural inheritance to teaching and imitation - but that's a rather different topic.

The information-theoretic perspective on heredity has deep roots in evolutionary biology. George Williams pioneered the idea in 1966. He wrote:

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 1966, page 25 - and later wrote:

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

- Williams 1992, page 11.

An informational memetics thus has strong roots in evolutionary biology and firm foundations in information theory - I claim.

Sylvain mostly critiques Daniel Dennett's conception of "information" - which he says is not clearly specified. That may be so - but I don't think that can be said of my conception of "information". I'm just using the bog-standard scientific and engineering meaning of the term - from Shannon and Weaver.

IMO, if there's a problem with memes-as-information, it is that it is very broad. Saying memes are "cultural" is a lot narrower and confines expectations much more. The idea of informational memes is a rather trivial concept - one which I mostly use to contrast with the position of Aunger - that memes are brain structures. That conception is too narrow to do the work required of it in a theory of cultural evolution.

Appendix

Here is Dennett distinguishing his concept of information from Shannon information (44 minutes in) - as I alluded to earlier in this post.

I'm not talking about bits when I'm talking about information, I'm talking about information in a more fundamental sense. Shannon information measured in bits is a recent and very important refinement a one concert with information but it's not the concept I'm talking about. I'm talking about the concept with information where when one chimpanzee learns how to tighten up crack nuts by watching his mother crack nuts there's information passed from mother to offspring and that is not in bits that is that is an informational transfer but has not accomplished in in any Shannon channel that is worth talking about.

This is a pretty embarrassing quotation from Dennett, IMO. Information which is not measured in bits - pah!

References

• Tyler, Tim (2008) Informational genetics
• Tyler, Tim (2015) What does it mean to say that memes consist of information?

An ensemble of evolutionary theories

Various folk have expressed concern that a generalized version of Darwinism that covers more phenomena would be weaker and would constrain expectations less - and would therefore be less useful.

John Maynard Smith once wrote:

The explanatory power of evolutionary theory rests largely on three assumptions: that mutation is non-adaptive, that acquired characters are not inherited, and that inheritance is Mendelian - that is, it is atomic, and we inherit the atoms, or genes, equally from our two parents, and from no one else. In the cultural analogy, none of these things is true. This must severely limit the ability of a theory of cultural inheritance to say what can happen and, more importantly, what cannot happen.

Recently, Alberto Acerbi has expressed a similar concern:

I am not convinced by the way-too-easy claims of “everything evolves!”, such as here, mainly because it seems to me that broad conceptions of evolution tend to have less explicative power

I've previously replied to Maynard Smith, writing:

Let's assume for a moment that his conclusion is true - and that it is harder to make predictions with cultural evolution than it is with biological evolution. So what? Theories of cultural evolution are not in competition with theories of biological evolution - they compete with other theories of cultural change that are less inspired by Darwinism.

Here I want to offer a different response - which is nonetheless still based on the idea that theories that cover different domains are not direct competitors.

Darwinism can be axiomatized. The axioms can be weakened and/or discarded, resulting in cut-down versions of Darwinism that apply under different circumstances. For example, conventionally, Darwinism requires copying. However without copying you can still have selection and goodness of fit - which are important components of Darwinism. Another common constraint involves what counts as a mutation. Random mutations constrain expectations a lot and result in easily falsifiable theories. However under some circumstances, such a constraint on mutation is not realistic. In cultural evolution, for example, it can be quite reasonable to model mental mutations as consisting of practically any change (short of recombination) that can happen inside an individual's mind. Mutations are still relatively small - but since they are the result of multiple generations of copying and selection within an individual's mind, they can be adaptive. Other Darwinian axioms can also be usefully weakened.

However, the resulting broad theories aren't in direct competition with the earlier narrow ones. They are applicable in different domains. As a result we have an ensemble of more-or-less Darwinian evolutionary theories - which are applicable under different circumstances. Having these extra theories in no way weakens the old, narrow versions of Darwinism from the textbooks. Those still work just as they did before. However the new, broader theories extend evolution into new realms, such as physics, chemistry, geology, astronomy and computer science.

Here's a diagram of the ensemble of evolutionary theories:

Theories vary along a one-dimension axis from 'specific' to 'general'. The more general theories are vaguer and constrain expectations less. However their corresponding advantage is that they are still applicable in application domains where narrower theories fail completely.

The expanded domain of evolutionary theory represented by universal Darwinism is like having a bunch of new tools in your toolbox. The complaints of John Maynard Smith and Alberto Acerbi are a bit like complaints that some of the new tools aren't as useful as one of the old tools was. That's OK - these are new tools that we didn't have before. You don't have to throw out any of your old tools in order to make room for the new ones. Instead, take delight in all the new things the bigger toolbox lets you do.

Of course this doesn't address the terminological debate about what deserves to be described as being 'evolutionary' or 'Darwinian'. However that's more of a 'small peanuts' debate, in my humble opinion. Universal Darwinism gives us a bunch of shiny new tools. We should try them out, see what they can do, and learn when best to use them.

Susan Blackmore: Humans as meme-machines

Susan Blackmore: Humans as meme-machines - Memes using us to fill planet from FutureStudies on Vimeo.

This video is from 2010.

My virtue signalling dilemma

I came up with the term 'virtue signalling' in 2011, and published about it here.

I made the term up after being irritated with Boyd and Richerson's term “heart on your sleeve hypothesis" from their "Solving the Puzzle of Human Cooperation" paper. It is often a bad idea to allow critics of a hypothesis to name it - and this was a case in point. Boyd and Richerson mentioned the signalling hypothesis mainly to criticize it while promoting their own rival ideas about group selection. By contrast, in my article, I promoted 'virtue signalling' to be the most significant cause of human cooperation after kin selection and reciprocity. A few other people have used the phrase before me - but never very seriously, it seems.

This article was written as part of my work on my 'Memes' book, which looked in more detail at culturally mediated cooperation than I had managed in my 2011 'Memetics' book.

Virtue signalling seems to be establishing itself as a popular term. However there's a foundational issue surrounding it which I haven't previously publicly addressed:

When I came up with the term I intended "virtue signalling" to refer to any kind of signalling self-worth - or denigrating of rivals. However, when I subsequently looked up the term 'virtue' in the dictionary I found that it had strong connotations of only referring to moral merit.

Clearly signalling of merit / worth / quality / value is a more general phenomena that just signalling moral goodness. I originally intended the term "virtue signalling" to refer to this more general idea. So, one of the examples I though of was a peacock signalling his 'virtue' to peahens. However, the dictionary suggests that the term 'virtue' means something more narrow: only moral merit.

One resolution would be to say that "virtue signalling" is a subset of "value signalling" - and that the latter includes Peacock signals, while the former does not.

The problem with this is that "value signalling" seems vague and ambiguous in other ways. It is already losing the popularity contest with "virtue signalling". I doubt whether this term has legs. Much the same goes for the other broader umbrella terms.

To deal with this, I'm inclined to double down on my original interpretation of the word 'virtue'. The dictionary does go on to offer some broader meanings of the term. Yes, describing a peacock's tail as a 'virtue' is a bit confusing, but I don't really see a significantly better solution. All signaling targets behaviour in the end - and what counts as 'moral' behaviour is pretty vague. So: we could also say that the peacock is signalling that having sex with it would be a 'good' thing to do.

Massimo's latest doubts

Massimo Pigliucci's latest doubts about cultural evolution can be found in the recent article: The Trouble with Cultural Evolution.

Alas, it's the same long-discredited nonsense as usual. Massimo doesn't know what he is talking about. I think at this stage one has to regard Massimo's writings as a case study in cognitive dissonance. How will Massimo continue to reconcile his doubts about Darwinian cultural evolution with the views of all the scientists who are now taking it seriously?

Massimo cites Lewontin's 1970 article "The Units of Selection. Explaining why he doesn't think the principles it lays down apply to cultural evolution. However, what he neglects to mention is that Lewontin stated himself that the principles did apply to cultural evolution in that very article. Here's what Lewontin said in 1970, on page 1:

It is important to note a certain generality in the principles. No particular mechanism of inheritance is specified, but only a correlation in fitness between parent and offspring. The population would evolve whether the correlation between parent and offspring arose from Mendelian, cytoplasmic, or cultural inheritance.

If you cite an article to support your position, and the author of the article disagrees with you in the same article, you should at least point that out.

Massimo's headache reminds me that one thing we haven't seen very much of so far is people publicly changing their mind on the topic. We clearly have a new generation of researchers who grew up with memes and understand the topic - but I've seen very few previous critics turn around and confess that they were mistaken. If scientists die before they change their minds on this topic, then we might be in for quite a lot more Darwinian revolution.

Update 2015-12-03: Massimo gloats over the reception of his paper here. It is all very well bending over backwards trying to find sympathetic interpretations of your opponents perspectives - but it is best not to bend over too far.

US president references internet meme

I don't know if it's the first time, but it's the first time I currently know about.

Dawkins reads the section on memes from his latest book

Here, Richard Dawkins reads the section about memes from his latest book, Brief Candle in the Dark: My Life in Science.

The book has around three pages on memes. The content focuses on the efforts of Susan Blackmore and Daniel Dennett to turn memetics into a proper scientific enterprise.

The function of ethics

From a biological perspective, ethical systems play several functional roles for their users.

In particular, ethics allows signalling virtue. Ethical systems are typically fairly other-oriented and they are frequently involved in manipulating the behavior of others. A shared ethical system can be a badge of group membership. A concern with ethics signals affluence: poor folk are more interested in means to obtain food and shelter.

These benefits are part of why humans are interested in ethics. However, from the perspective of memetics, these benefits aren't the real function of ethical systems - since they accrue to the human hosts involved. Since ethical systems are socially transmitted memeplexes it is reasonable to ask how their features benefit not their hosts, but themselves.

In memetics, the primary function of ethical systems is to spread. To do this, they need to be extensively publicly discussed. They also need to be taught to other individuals - the younger the better. This perspective probably helps to explain why there is so much public discussion about ethics. Not only do humans signal their virtuous nature to others by exhibiting their ethical systems, the ethical systems are themselves directly adapted to spread between hosts via teaching and instruction.

The signalling aspects of ethics play double-duty. On one hand, ethical signalling ethical content lets human hosts signal to other humans how virtuous they are - and how much spare time they have. The signalling of ethical content also directly helps ethical systems to spread.

2014 attack on cultural evolution by Jerry Coyne

I got around to reading one of Jerry Coyne's more recent critiques of cultural evolution:

If evolution really weren’t based on heritable and permanent changes in DNA sequence, that would be surprising, and at least a major change in perspective. The “revolution” proponents argue that this does happen in two ways.

First, there is cultural evolution: stuff is passed on not by genes, but by learning. This, of course, is nothing new: Dawkins wrote about memes—units of cultural inheritance—way back in 1976, drawing a parallel between genetic and cultural evolution. But that was a parallel, and one that I don’t find terribly enlightening. But cultural inheritance is of course important in some species, including all animals that teach their young. The authors give some examples:

In addition, extra-genetic inheritance includes socially transmitted behaviour in animals, such as nut cracking in chimpanzees or the migratory patterns of reef fishes.

So what’s new? Yes, we can model how this works, but learning it itself an evolved ability, and modeling social evolution will involve things beyond the purview of evolutionary theory. Cultural evolution is not genetic evolution, and hence not part of the SET, which rests on changes in genes. Cultural evolution is important, but it’s no more part of SET than is the “evolution” of changes in automobile style over the years.

First let's look at the idea that "modeling social evolution will involve things beyond the purview of evolutionary theory".

Surely modeling DNA evolution involves things beyond the purview of evolutionary theory. It involves modeling aerodynamics, photosynthesis, echolocation, turbulence, biochemistry, structural stability, osmosis - and all manner of other things.

The idea that modeling cultural evolution goes beyond evolutionary theory while modeling DNA evolution does not seems like simply a basic confusion about the explanatory role that evolutionary theory plays.

As for: "Cultural evolution is not genetic evolution, and hence not part of the SET [Standard Evolutionary Theory], which rests on changes in genes" - that goes to the definitions of 'genes' and 'genetics'. If you have 'genetics' as the study of heredity, and 'gene' as the unit of heredity - as I favor - then cultural evolution is indeed genetic evolution, and does indeed involve changes in genes.

This is an argument about terminology. However, even without the terminological debate, defining the domain of evolutionary theory in terms of DNA genes - as Coyne curiously proposes - doesn't make any sense. Ultimately, this idea will be ditched as being based on an outdated classification scheme. Our ancestors weren't based on DNA, or descendants won't be based on DNA, and many modern evolving systems are not based on DNA. A DNA-based classification scheme is simply an impoverished one. It is deeply unscientific to divide evolutionary theory into evolution based on DNA genes and other kinds of evolution.

Natural sorting

You may have heard about natural selection. There's also natural sorting.

Sorting is a process which involves creating order out of disorder by rearrangement.

Sorting is ubiquitous in nature. There are pecking orders, lek rankings and dominance hierarchies. Rocks sort themselves by size on beaches and gasses sort themselves by density in the atmosphere.

In computer science, filtering and sorting get similar space on bookshelves. Knuth's epic volume 3 of The Art of Computer Programming is devoted to Sorting and Searching. This equal billing seems fairly reasonable to me.

However, sorting is rarely mentioned by physicists, biologists or evolutionary theorists. In evolutionary theory in particular, filtering seems to get all the limelight - while sorting is largely ignored.

I think the neglect of sorting is probably a case of terminology influencing thought. Selection is regarded as a central concept in evolutionary theory - while sorting doesn't enjoy the same status.

Whatever the reason for its neglect, sorting is a pretty important phenomenon. Environmental gradients are common (e.g. depth and altitude). Often organisms get sorted along the gradients - with the most competent organisms getting the best niches. For humans proximity to city centers results in an important gradient. The poorest humans get sorted to the outskirts by property prices - while a lot of courtship of the most desirable mates takes place in central locations.

Sorting and filtering are often combined in biological systems. Sorting is fairly often followed by filtering. In some cases the filtering is performed by mates - who choose the best partners they can find. In other cases, filtering is done by predators. For example, when a cheetah chases gazelles, the prey naturally sort themselves from fastest to slowest. The cheetah then filters out the slowest one.

It is worth noting that sorting has other effects on evolutionary dynamics that aren't much to do with sorting being a prelude to filtering. Consider assortative mating, for example. That's not really sorting followed by filtering - the sort itself is what affects the evolutionary dynamics.

It is possible to classify natural sorting into two main types based on the mechanism involved. Some types of sorting involve direct comparisons between neighbors. Others do not - and instead rely on different entities having different speeds or trajectories. Examples of sorts that do not involve direct comparisons between neighbors include the gazelle example above, electrophoresis and the ink diffusion spectrum phenomenon.

Sorting processes that involve neighbour copmparisons are dissipative: they create order and they need a power supply and generate heat. Sorting processes that don't compare the entities they are sorting tend to be more reversible. For example, a prism sorts light rays. However it isn't dissipative: the effect of a prism can be reversed by another prism. This observation suggests the names 'dissipative sort' and 'reversible sort' for the two categories of sorting processes.

Sorting is usually thought of as being a one dimensional phenomenon. However natural sorting also takes place in two and three dimensions. Here's a two-dimensional sort of ink pigments:

The dimensionality involved is not a defining characteristic of sorting processes.

It is sometimes possible to describe dissipative sorting operations in terms of selection. For example, when you shake your breakfast cereal, and the largest lumps rise to the top that process could be described as a series of many individual "selections" in which layers of the cereal act as porus sieves that allow small particles to fall through and select against large particles. This sort of re-description is possible for sorts that involve neighbor comparisons. It is usually less helpful to describe sorts that do not involve neighbor comparisons in terms of selection. Even where re-description in terms of selection is possible, describing sorting as a series of filtering operations is often long-winded and obtuse. It is usually best to simply describe sorting processes using the term "sorting".

One of the notable exceptions to the neglect of sorting by evolutionary theorists is John Wilkins. He has long been reframing natural selection in terms of sorting. I didn't get the idea from him, though I had long been aware of him framing evolution in terms of sorting. For an example of John's thinking on the topic see the "Evolution and Chance" talk.origins FAQ.

Memes and host lifespan

Cultural evolution has led to increased lifespans among many modern humans.

Symbiology has some basic models of how symbiotes affect host lifespan which seem likely to be applicable to cultural evolution. When a symbiont usually dies with its host, it can sometimes pay for it to divert resources from host reproduction into host maintenance processes. That makes the host live for longer and results in more opportunities for the symbiont to reproduce before it perishes with its host. Copies of individual memes do perish with their hosts - and this model is broadly consistent with the observed longer lifespans produced by cultural evolution to date.

However, there's an alternative scenario described by the same kind of model. If there's a lot of horizontal transmission of symbionts between hosts, the symbionts can sometimes profit by converting the hosts' resources into copies of their own heritable material as quickly as possible. This is the strategy employed by the Ebola virus, for example. Rather than increasing host lifespan, these types of parasite dramatically decrease it.

When does this latter scenario arise? The models are fairly specific about when this type of scenario is likely. It happens when the host density is high or when there's a lot of opportunities to spread between hosts.

The ability of memes to leap from host to host has dramatically increased over the last century. These days, mobile phones deliver memes pretty directly into peoples' brains in a near-constant stream. Horizontal meme transfer has increased dramatically in modern times - and it looks set to continue to rise. Our ability to pack humans together in huge cities has also continued to rise.

This raises some questions. What can be done to avoid going into an era in which memes shorten host lifespans - and rip through host resources like the Ebola virus does? Also, we have been seeing a lot of horizontal meme transmission for a while now. Yet if you look at the most meme-rich areas of the planet - such as Japan - host lifespans are excellent. Why are we not in an Ebola-like era already?

The most obvious answer is that memes that quickly kill their human hosts are selected against in various ways - by host immune systems, and by active suppression by groups of humans. People do get sucked into meme-spreading cults that rip through their resources Ebola-style - but education defends against this fate - and so do nearby friends and relatives.

An important reason for studying these dynamics is to see whether we can avoid problems. Will we see plagues of parasitic memes mirroring the 1918 flu epidemic? Will we see persistent draining influences - mirroring the effect of the HIV virus on lifespan in Africa? What about mixed bag pathogens? For example, smallpox helped Europeans to conquer native American tribes - while simultaneously killing many Europeans.

So far the influence of memes on lifespan seems consistent and positive. More memes are strongly correlated with longer lifespans. However I think it is too early to say whether this positive trend will continue without interruption. We should strive to understand these dynamics in order to help us to avoid problems in the future.

Susan Blackmore on machine ethics

Susan Blackmore weighed in recently on the topic of machine ethics - in article titled: It’s too late to give machines ethics – they’re already beyond our control.

While I generally think that students of cultural evolution ought to be well placed to contribute to prediction of the consequences of our actions in this area, I found several things to object to in Sue's analysis. On problem is the article's title. It strikes me as being defeatest. We ought to at least try.

Later in the article, Susan writes:

Replicators are selfish by nature. They get copied whenever and however they can, regardless of the consequences for us, for other species or for our planet. You cannot give human values to a massive system of evolving information based on machinery that is being expanded and improved every day. They do not care because they cannot care.

This seems like confused reasoning to me. We have examples of companies, governments and other organizations which have codified various human values. These are often in the form of 'laws' or 'rules'. If the argument is that memes and genes 'cannot care' because they are selfish replicators, then we have many examples of complex meme or gene products which do care - or behave as though they care.

Blackmore looks as though she is arguing from selfish memes to selfish organisms here. If so, that is a mistake parallel to the mistake that Richard Dawkins made in The Selfish Gene. Dawkins (1976) wrote:

I shall argue that a predominant quality to be expected in a successful gene is ruthless selfishness. This gene selfishness will usually give rise to selfishness in individual behavior. However, as we shall see, there are special circumstances in which a gene can achieve its own selfish goals best by fostering a limited form of altruism at the level of individual animals.

...and then...

Let us try to teach generosity and altruism, because we are born selfish.

He subsequently had to back-pedal, writing the following belated retraction (2006):

I do with hindsight notice lapses of my own on the very same subject. These are to be found especially in Chapter 1, epitomised by the sentence ‘Let us try to teach generosity and altruism because we are born selfish’. There is nothing wrong with teaching generosity and altruism, but ‘born selfish’ is misleading. In partial explanation, it was not until 1978 that I began to think clearly about the distinction between ‘vehicles’ (usually organisms) and the ‘replicators’ that ride inside them (in practice genes: the whole matter is explained in Chapter 13, which was added in the Second Edition). Please mentally delete that rogue sentence and others like it.

Selfish memes could result in selfish companies, governments and organizations - but it ain't necessarily so. Saying that such complex entities 'cannot care' seems like an unwarranted generalization to me. Maybe memes "cannot care" - but so what? It is memeplex products that we are mostly interested in when discussing machine intelligence. There's no good reason why they can't care.

Anyway, this topic is an important reason to study memetics. We need the best science has to offer to help us predict the consequences of our actions. The existing man-machine symbiosis probably won't last forever - there will probably be a merger or one side will assimilate the other. It looks as though we have enough power to be able to influence the outcome in a variety of ways - to the extent that technological determinism leaves some aspects of the outcome open. There's a lot at stake - and we should try our best to figure out what we should do.

Matt Ridley: Evolution of The Cloud

Matt Ridley: The Evolution of Everything

The book, "The Evolution of Everything: How New Ideas Emerge" by Matt Ridley is out later this month.

The book has its own domain: http://www.theevolutionofeverything.co.uk/ Here is the book on Google books and Amazon. Peter Forbes says it is Ridley's "magnum opus". High praise - since many of Ridley's other books are pretty good.

The book has a form of Universal Darwinism at its core. Ridley writes:

Indeed, to borrow a phrase from a theorist of innovation, Richard Webb, Darwinism is “the special theory of evolution”. But there is a general theory of evolution, too, and it applies to society, money, technology, language, law, culture, music, violence, history, education, politics, God, morality. The general theory says that things do not stay the same; they change gradually but inexorably; they show “path dependence”; they show descent with modification; they show selective persistence.

The special and general theories of evolution. I love it. What a great way to express the idea of Universal Darwinism. I don't like the term "Darwinism" being reserved for the "special" theory. Rather like Einstien, Darwin pioneered both the special and general theories of evolution; we should give him credit for that.

From the list of examples, it looks as though Ridley might be missing out on Darwinian Physics, though.

You may find that the first chapter is available free here. It's a philosophical/historical overview of bottom-up explanations.

Google Books has the first two chapters online here.

Reviews:

• Ronald Bailey: Good News Is Unplanned - How culture, economies, technology, and government evolve
• Michael Shermer: No Planning Necessary
• Peter Forbes: The Evolution of Everything: How New Ideas Emerge by Matt Ridley
• Alberto Acerbi: The evolution of what?? A bad book (and a bad review).
• John Gray: Does Darwin’s theory apply to everything, from the internet to leadership? The columnist and disgraced banker has written a bumptious, misguided book.

Symbiont kin selection

Cultural kin selection proposes that cooperation can arise due to shared memes - as well as due to shared DNA genes.

However, cultural kin selection can be thought of as a special case of symbiont kin selection - an idea that may apply to many types of close living organisms.

Colony life - as found in ants, bees and mole rats - leads to increased levels of transfer of symbionts between the organisms involved (often due to sheer close proximity). The mole rats eat each others feces - and so come to share the bacteria they need to digest their tubers. Ants frequently cultivate fungi - and their nests are heavily dominated by fungi digesting rotting wood. They have many other symbionts too - there are special bacteria that they use to suppress the growth of competing strains of fungi, for example.

As well as acting on the host genes, kin selection acts on the genes of the symbionts too. If the symbionts in different organisms are related, then - to the extent that these can manipulate the behaviour of their hosts in favour of cooperation - they will tend to do so.

Probably ant fungus is the most extreme example of this form of kin selection. Though distributed the fungus is closely related - more so than the ants themselves are. It forms something like a massive multi-cellular organism in each ant colony - a superorganism. It may benefit from that ants acting as a coordinated whole more than the ants themselves do. The ants snack on the fungus - so it probably has a variety of ways of manipulating ant behaviour - through taste, smell and direct chemical action.

Seen from the crude perspective of Hamilton's rule, shared symbiont genes may elevate relatedness further. For example, intra-colony relatedness in naked mole rats has been estimated to be 0.81 - but this relatedness figure is based on the host genes. As with other mammals, most of the genes involved are not mole rat nuclear DNA, but are genes in gut microorganisms. The bacterial cells outnumber those of their hosts by a factor of ten. What happens to that relatedness figure once "horizontal" sharing of bacteria is accounted for? It probably goes up: a lot of those bacteria will be asexual clones.

For an example relevant to humans but still involving DNA genes, consider yeasts - as found in bread, wine and beer. Many yeasts have become human-transmitted symbionts. The main way they spread their genes around in the world involves human social contact. If they can somehow make their human hosts socialize more with other humans, they are likely to directly benefit. Kombucha may be one of the best examples of a socially-transmitted yeast - since it often spreads directly through peer-to-peer contact. Are Kombucha enthusiasts more sociable than other humans? Probably. But are they more sociable as a result of being manipulated by the Kombucha? It is an interesting question that deserves further study.

Symbiont kin selection is a bit different from the symbiont hypothesis of social evolution - but it is fair to say that these ideas are related.

Symbiont kin selection should illuminate cultural kin selection, which can be accurately modelled as a special case of it involving cultural symbionts - rather than DNA-based ones.

Symbiont kin selection is a neglected idea in social evolution. Because of lack of study, it is not easy to assess its overall significance - but it could easily be a big deal. If you look at humans, a lot of their cooperation is based on shared memes - rather than shared genes. In the workplace, for example, shared memes are ubiquitous - and shared genes are rare. Even within family life, shared memes are ubiquitous. Cultural kin selection could easily explain more cooperation than genetic kin selection does. This example illustrates the potential power of symbiont kin selection - but maybe it is equally powerful in other eusocial creatures. More powerful, maybe - since they are further along in the road to colony life than we are. Symbiont kin selection could easily be stronger in them than it is in us.

The meaning of heredity

I generally use the term "heredity" to refer to the transmission of traits from one generation to the next.

However, I notice that some sources differ - confining the idea of "heredity" further. The Encyclopedia Britannica is explicitly DNA-gene centric:here:

heredity: the sum of all biological processes by which particular characteristics are transmitted from parents to their offspring. The concept of heredity encompasses two seemingly paradoxical observations about organisms: the constancy of a species from generation to generation and the variation among individuals within a species. Constancy and variation are actually two sides of the same coin, as becomes clear in the study of genetics. Both aspects of heredity can be explained by genes, the functional units of heritable material that are found within all living cells.

Reference.com confines the idea of heredity even more - to organisms that experience meiosis - with this:

heredity:the transmission of genetic characters from parents to offspring: it is dependent upon the segregation and recombination of genes during meiosis and fertilization and results in the genesis of a new individual similar to others of its kind but exhibiting certain variations resulting from the particular mix of genes and their interactions with the environment.

These sources are simply wrong. However, their mistake is widespread and leads to confusion about cultural evolution. For example, Larry Moran defines evolution using the term 'heredity' - saying: "Evolution is a process that results in heritable changes in a population spread over many generations." - and then goes on to argue that:

I've already alluded to one of the classic questions that a proper definition can answer — the increased height of Europeans over the past five centuries. Armed with a good definition of biological evolution we can focus on one of the key requirements; namely, heritable change. It turns out that the increase in height is due to a better diet and not to genetic changes. Therefore, this is not evolution according to the scientific definition.

This is a serious conceptual mistake. European diet has improved (largely) through memetic evolution. Memes are passed from one generation to the next in cultural evolution - and rather obviously this should meet any sensible scientific definition of evolution - as is attested to by the now-massive literature on cultural evolution. Yet Moran dismisses it - apparently due to his conception of the definition of the term 'heredity'. This seems like a spectacular mess to me.

Larry is not alone in this evolutionary denialism. Here's Mark Ridley on why cultural evolution doesn't qualify as being "evolution":

Changes that take place in human politics, economics, history, technology and even scientific theories are sometimes loosely described as evolutionary. In this sense "evolutionary" means mainly that there has been change over time - and perhaps not in a preordained direction. [...] human ideas and institutions can sometimes spit during their history - but their history does not have such a clear-cut branching tree-like structure as does the history of life. Change and splitting provide two of the main themes in evolutionary theory.

His complaint appears to be that cultural evolution is too reticulated - one of the most dopy objections to cultural evolution ever - once you consider how reticulated bacterial evolution is.

Anyway, these days, almost everyone agrees that cultural evolution is a type of evolution. The remaining debate in the area is mostly over whether cultural evolution is Darwinian. However we obviously have a mopping-up operation to do - as some folk don't even regard cultural evolution as being a type of evolution! That position seems indefensible to me.

In light of cultural evolution

There's a recent trollish article doing the rounds titled:

The Theory Of Evolution Does Not Apply To Modern Human Beings.

Basically it argues that humans don't behave as the theory of evolution dictates. For example, the more resources you give a human, the fewer children they have.

I think this article nicely illustrates the confusion associated with a lack of understanding of cultural evolution. Almost everything in the article makes me think: "yes: but only if you ignore cultural symbionts".

It's well-known that parasites can reduce host reproduction - and even drive hosts extinct. The demographic transition is driven by cultural symbionts that reduce host reproduction. This has been extensively modeled by cultural evolution enthusiasts. This isn't contrary to the theory of evolution - you just have to include the evolution of memes in order to understand it.

If you add resources to a human population the memes absorb the resource faster than the human hosts do - and more memes often means less host reproduction.

Something very similar happens in the organic realm - if you add sugar to a human population. A little sugar might help with reproduction - but beyond a certain point, fertility begins to decline. Instead of making more human genes, the sugar fuels the reproduction of gut microbes at the expense of the genes of the human host. The host's belly swells up to accommodate them all. Eventually the host is effectively sterilized.

This all illustrates the dictum: Nothing in human evolution makes sense - except in the light of cultural evolution.

References

• Boots, M. and Sasaki, A. (2002) Parasite-driven extinction in spatially explicit host-parasite systems.
• Hwang T.W., Kuang Y. (2003) Deterministic extinction effect of parasites on host populations.