Tim Tyler: Durham, Coevolution (review)

Transcript:

Hi. I'm Tim Tyler, and this is a review of this book:

Coevolution - Genes, Culture and Human Diversity - by William Durham

This is a book on how genetic and memetic systems coevolve. It was written in 1992. At the time of its publication, it was probably the best available book on the topic.

The book is pretty good. It covers topics such as the coevolution of agriculture memes, malaria resistance genes and lactose tolerance genes. In each case, the memes and the genes evolve together and influence each other - usually with the memes leading and the genes following. The author has a good grasp of both the theory and the anthropological literature on the topic. I was also pleased to see that the book endorses and uses the "meme" terminology from Richard Dawkins.

There aren't too many flaws in the book. However, the author reviews the work of previous authors in the area - and does a pretty good job of pointing out the flaws in their work. One of the few problems that I noticed was that the author seemed to lack a good understanding of evolution within individual minds. This led to a number of incorrect statements relating to alleged differenes between cultural and organic evolution. However, for the most part the author focused on areas where the effects of this problem were minimized.

One slight oddity about the book is its subject matter. Most of the previous academic books in the same general area had focused on gene-meme interactions. This book has the exact same focus. Retrospectively, it seems as though academics were attempting to master the more complex and difficult topic of gene-meme coevolution over deep time before they had properly pinned down a decent theory of how memes coevolve with their host's brains in the short term.

A few theories could account for this curious progression: perhaps academics like to work on hard problems; perhaps they like to show off; or perhaps they were copying each other. The term gene-culture coevolution was first used by academics without much sign of understanding of cultural evolution as a Darwinian system. The term stuck and subsequent authors continued to work in the same area. This led to a curious bias in the field, where short-term cultural evolution itself was practically ignored, and the focus was on how genes and culture interacted over deep time. The focus of this field was events in the distant past. By contrast, cultural evolution itself is powerfully relevant to modern times - and can easily be studied using natural experiments and laboratory experiments. What it would have been nice to have seen in, the 1990s, was theorists escaping from the rut that academia had got itself into, and exploring the relatively uncharted territory of how culture evolves. However, this book didn't to do that - and instead ploughed deeper into the existing furrow - of how cultural variation influences genetic evolution.

Another omission from the book is meme-meme coevolution. A modern theory of coevolution relating to humans would normally include memes, DNA genes and ideas copied within minds that are not socially-transmitted. By my count these three basic types of copied entity give rise to six possible kinds of coevolution between quite different types of structure. This book only considers the case of meme-gene coevolution. However, there's quite a bit more to coevolution than that.

Nonetheless, for 1992, this book seems quite advanced. A lot of effort evidently went into its production. The book is fairly clear and readable. It was a promising start - which makes the field's subsequent slow progress more puzzling. Perhaps not enough people bothered to read it.

Enjoy,

Daniel Dennett on HARDtalk

• HARDtalk - Professor Daniel Dennett Part 1
• HARDtalk - Professor Daniel Dennett Part 2

Daniel Dennett: Religion is like 'the common cold'

The interviewer tries to lead Daniel on a bit here.

This is an excerpt from the HardTalk interview.

Universal Darwinism - proposed book cover

After my forthcoming Memes book, I'm planning a Universal Darwinism book.

Today I designed a prototype cover. Here is the idea:

Astute observers might notice some similarities with the cover of my 2011 book on memetics.

Susan Blackmore - short videos about memes

Here is Susan Blackmore in quite a number of short videos about memes:

• What are memes?
• The idea of memes
• Memes and the internet
• Memes today
• Avuncular advice from Daniel Dennett
• Richard Dawkins writes a foreword for The Meme Machine
• Imitating and memes are human-only features
• Serious illness and Daniel Dennett's Darwin's Dangerous Idea

These are all probably from around the year 2000.

Meme literacy

Understanding memes is basic to scientific literacy in the modern world - where memes are ubiquitous. However, due to a turbulent and muddy history, knowledge of memes and memetics is currently largely confined to a scientific elite. Large numbers of people are confused about the issue of how culture evolves - even though we are over 150 years since Darwin's landmark publication.

Because an understanding of memes is so important, I propose that we should have a term to refer to knowledge and understanding of what memes are - and how they evolve. "Meme literacy" is my proposal.

Those with a reasonable understanding of memes are meme literate. The term meme illeterate sounds a bit insulting - so maybe we could call the world's meme sceptics and critics meme challenged.

Tim Tyler: Boyd & Richerson, Culture and the Evolutionary Process (review)

Transcript:

Hi. I'm Tim Tyler, and this is a review of this book:

Culture and the Evolutionary Process by Robert Boyd and Peter J. Richerson

This book was published in 1985. It is the best book on cultural evolution from the 1980s. It builds on top of earlier work by Cavalli-Sforza and Feldman, who had outlined a similar approach, in less detail in 1981. Boyd and Richerson do a better job than previous authors did of placing their material in its historical context, and offered a better review of other related material.

However, the book has quite a few problems:

It is full of densely-presented mathematical models. I think that these hinder more than they help. Maybe some people will be impressed by them, but I'm not really among them.

The book introduces terminology for cultural evolution. Much of this has not dated well. It uses the term "guided variation" - where, these days, most people would say "directed mutation". The book uses the term "biased transmission", whereas these days we would just say "cultural selection" or just "selection". Hardly anyone uses the term "biased transmission" these days. The book uses the term "cultural parents" and the term "cultural offspring" - but these are not used refer to memes, but rather to their associated hosts. This does not seem like good terminology to me.

The book is almost entirely free of symbiology. This is unfortunate, since any sensible modern theory of cultural evolution must necessarily be heavily based on symbiology. They do mention the concept at one point. They say:

Horizontal transmission is analogous in some ways to the transmission of a pathogen and Cavalli-Sforza and Feldman have used epidemiological models as a starting point for their development of theory. The item of culture being spread horizontally acts like a microbe that reproduces and spreads rapidly because it is "infective" and has a short generation length compared to the biological generation length of the "host". Fads and fashions and technical innovations are familiar examples.

This material is fine - as far as it goes. However three sentences is not really adequate coverage for this concept. You really need to cover cultural parasites, mutualisms, immunity, arms races - and so forth. Many biologists were still getting to grips with the significance of symbiology in the 1980s. However Cloak and Dawkins had previously managed to present a symbiology-aware version of cultural evolution in the 1970s. Boyd and Richerson failed to pick up on this. What do they offer instead? They say:

This does not mean that cultures have mysterious lives of their own that cause them to evolve independently of the individuals of which they are composed. As in the case of genetic evolution, individuals are the primary locus of the evolutionary forces that cause cultural evolution and in modelling cultural evolution we will focus on observable events in the lives of individuals.

This is not a good approach. It is like saying: to study the evolution of smallpox, we should focus on the human victims. The problem with this is that insufficient attention is given to the smallpox virus. You could say that smallpox exhibits horizontal and oblique transmission between its hosts. It exhibits "biased transmission" - due to different levels of resistance from host immune systems. These processes can all be modeled. While this sort of approach would result in some progress, it seems like a fundamentally misguided way of viewing the situation.

Cultural information exists apart from its human hosts. As well as spending some of its time residing in host brains. It exists in libraries, on discs, inside computer memory, in air vibrations and as radio waves. Libraries can burn down, sounds can suffer from interference, and compute memory exhibits senescence. Culture partly evolves outside its primary hosts. The result is a symbiosis between two different kinds of living and evolving systems. If you focus on observable events in the lives of individuals, you are likely to miss all this material.

Though this book presents a closer link between evolutionary processes in the organic and cultural realms than most previous authors managed, Boyd and Richerson don't really take the links far enough.

The main problems seem to be that, at this stage in their thinking, they didn't appreciate symbiology properly, and they didn't understand that evolution happens within minds, during individual learning - as well as between them, during social learning.

The authors have a section at the very start of their book comparing genetic and cultural evolution. They argue that humans get genes from their parents, but their memes come from a range of individuals. However, humans get viral and bacterial genes from a wide range of individuals as well. This is not really a valid difference between genetic and memetic variation. They argue that meme lifespans are different from host lifespans. However, this is true for DNA genes inside parasites too, and isn't a special feature of cultural evolution. They argue that humans get their genes at birth, while they acquire their culture gradually. However, humans acquire DNA genes gradually as well - it is just that these genes are sometimes inside parasites. They argue that cultural transmission occurs after some development has taken place. Yet this too also happens when acquiring parasites. They argue that cultural variation may be affected by life events, and then transmitted to others. Yet again, this happens with parasites. If you consume antibiotics, you may subsequently transmit antibiotic-resistant bacteria that you have acquired during your lifespan to others.

Boyd and Richerson's list of differences between cultural and organic evolution seems almost entirely invalid. This would not matter, except for the fact that much of the project of studying cultural evolution revolves around the issue of what the differences are. Where cultural and organic evolution exhibit the same dynamics, we can mostly use existing models. The rest of the book is largely devoted to mathematical models of the differences they identified.

While it would be interesting if researchers needed a broad array of new mathematics to model cultural evolution, for the most part, the dynamics of cultural evolution are largely shared with epidemiology and symbiology - and models from these fields can be adjusted to deal with culture with relatively minor tweaks - to cover phenomena such as conformist transmission which have few parallels in the organic realm. What needed doing in the 1980s was strengthening and expanding the models of epidemiology and symbiology to cover culture. Instead what we got was an attempt to drive a mathematical wedge between our models of cultural and organic evolution.

In the book, Boyd and Richerson put in a plea for simple mathematical models. Can their approach be excused on the grounds that they are simplifying? Not really. It isn't "simpler" to develop many unnecessary mathematical models based on illusory differences. Rather it results in increased complication through the proliferation of models. Nor is it simpler to only focus on one symbiont in a symbiotic relationship. The result is a byzantine maze of horizontal and oblique transmission vectors. Best to recognise both partners in the relationship and stick to two types of lineage with pure-vertical transmission within each of them. This is what is done with parasites and symbionts in the organic realm. The cultural realm is no different in this respect.

Overall, this was an important book. It probably wasn't as influential it could have been - since its mathematical models and technical style probably presented a barrier for many readers. Still, most modern workers in the field do cite it, recognising its pioneering role. Since its publication, Boyd and Richerson have continued plugging away at the topic. They have produced a steady stream of papers on the subject - including many valuable ones - along with a few more muddled ones. Despite its virtues, this book's problems - or perhaps the perspective of its authors - seems to have resulted in a bit of a hangover for cultural evolution within academia. Dawkins had clearly presented a framework which was more correct in a number of respects many years before. However, over time, these two camp's relationship increasingly turned into a rivalry. Instead of a synthesis, the result seemed to be tribalism and conflict.

The book was probably the first detailed treatment in academia of maladaptive forms of culture - the insight that cloak and Dawkins originally presented. It pointed out that kin selection apples to memes. It applied runaway selection processes to memes. It modeled memetic conformity. It discussed the possibility of memes sterilizing their hosts and diverting their reproductive resources away from gene propagation and into meme propagation. Overall, there is much of interest in it.

Enjoy,

Memetic engineering

The term "Memetic Engineering" refers to deliberative meme creation, modification and combination. It was named after genetic engineering.

Many memes and memeplexes are engineered - rather than being the product of unconscious selective forces.

Engineered memes are used in marketing, advertising, entertainment, politics, warfare, religion and education - among other fields.

Techniques

Many techniques are used while engineering memes. Prominent among them are:

• Memetic hitchhiking;
• Random and deliberative recombination;
• Random and deliberative mutation;
• Retromemes;

One of the techniques used in genetic engineering involves recombinant DNA. Memetic engineering similarly features recombinant memes.

As with practically any engineering project, memetic engineering is likely to involve an iterative generate and test cycle - as well as use of evaluation under simulation.

Memes interact with the human brain - specialists in psychology are often involved. Many modern memes also interact with computers - and modern memetic engineers often use computer networks to distribute their products.

Memes typically face prepared memetic immune systems. Penetration can be assisted by finding holes in the defenses, disabling them or taking advantage of naturally-weakened states.

Once memes are engineered, they are distributed using seeding. One technique there is big seeding.

Examples

An early example of a deliberately-engineered meme was described in Wired magazine - in the form of Mike Godwin's Meme, Counter-meme article.

Another example is music videos. Gangnam Style was memetically engineered - and now has over 2 billion views - an indication of its success.

Web sites

Within the last decade various memetic engineering sites have sprung up associated with internet memes - among them the imageboard 4chan and a wide range of image macro generators.

Double-edged sword

Like most powerful technologies, memetic engineering is a positive force which also has significant negative potential. Social engineers could use memetic engineering to create a benevolent utopia - as envisaged by B. F. Skinner. However, today, memeticallly engineered pathogens currently cause a significant quantity of damage. In particular the obseity epidemic, addictive drugs, pornography, movies and computer games represent widespread memetically-engineered plagues.

In some areas, indoctrination targetted at children uses memetically-engineered propaganda to turn kids into soldiers. In other cases, memetic engineering is used to recruit new cult members. Memes can have a dark side - and engineered memes are not excluded from this.

Reputation

Genetic engineering has acquired a dubious reputation. With memetic engineering the situation is less clear. Few object to engineered memes on the grounds that they are engineered - since so many memes are engineered.

Sometimes engineered memes are inferior to their naturally-evolved counterparts. For example, Esperanto is a memetically engineered language. It was designed - rather than evolving over a long period of time - and has a very regular grammar. However it is widely recognized that Esperanto sucks. This situation mirrors some of the objections that are made to genetic engineered products.

Eumemics

Much as Eugenics is a movement based on improving the human genes in the gene pool, eumemics is a movement based on improving the memes in the meme pool. As with eugenics there are "positive" and "negative" forms of eumemics. However unlike eugenics, eumemics seems relatively uncontroversial.

Prevalence

While genetically engineered pathogens are rare and cause little damage, memetically engineered pathogens are common, largely unregulated, and cause damage in a massive scale. While there are some attempts to restrict addictive drugs, nicotine, alcohol and caffeine are widely available and many millions are addicted.

Consciousness spectrum

Memetic engineering can be seen as one end of a spectrum, that runs from natural selection, through unconscious selection and domestication to engineering.

Books (fact)

• Made to Stick: Why Some Ideas Survive and Others Die (2007) - Chip Heath and Dan Heath
• Contagious: Why Things Catch On - Jonah Berger (2013);
• The Science of Marketing: When to Tweet, What to Post, How to Blog, and Other Proven Strategies - Dan Zarrella (2013);
• Zarrella's Hierarchy of Contagiousness: The Science, Design, and Engineering of Contagious Ideas - Dan Zarrella (2011);
• Walden Two - B. F. Skinner (1948);
• Beyond Freedom and Dignity - B. F. Skinner (1971);
• Rumor Psychology: Social and Organizational Approaches - Nicholas DiFonzo
• The Chalice and the Blade: Our History, Our Future - Riane Eisler;

Books (fiction)

• Orwell, George - 1984 (1948);
• Burgess, Anthony - A Clockwork Orange (1986);
• Asimov, Isaac - The Foundation Novels;
• Gurdjieff, George - Beelzebub's Tales to His Grandson;
• Stephenson, Neil - Snow Crash;
• Stephenson, Neil - The Diamond Age;
• Chambers, Robert W. - The King in Yellow;

References

• Wikipedia (2013-) Memetic_engineering;
• David Hales (1996)Memetic Engineering and cultural evolution;
• Michael Wilson (1993) Memetic Engineering - PsyOps and Viruses for the Wetware;
• Mike Godwin (1994) Meme, Counter-meme;
• James Gardner (1996) Memetic Engineering;
• Dan Zarrella (2008) How to Make and Spread Rumors;
• M. Alan Kazlev (2001) Memetic Engineering, Memgineering;
• By Alex Burns (2001)Memetic Engineering;
• Tim Tyler (2012) The science of intelligent design - ;
• Tim Tyler (2010) Military memetics;
• Aaron Muszalski (2010) Weaponizing Cultural Viruses;
• Jeremy J. Whitlock (2002) Memetic engineering and public acceptance
• Rushkoff, D. (1996) Media Virus! Hidden Agendas in Popular Culture;

Cultural evolution's scientific lag

The "gene" revolution in evolutionary biology came after the discovery of the molecular basis of DNA genes - and around the time that kin selection came on the scene. Probably both events were significant facilitators of the revolution.

Cultural kin selection has been fairly rarely mentioned until recently, and there's a lot to say about it - as I am finding out by writing by book chapters about cultural nepotism, and cultural eusociality.

Kin selection - more than most aspects of biology - forces you to adopt the genes' eye view, in order to understand which behaviours are likely to promote which genes. It's the same with cultural kin selection: you're really forced to adopt the meme's eye view - in order to understand what is going on.

Another factor that parallels the situation in the organic realm is group selection enthusiasm. In the 1960s, many of the same topics that were eventually modeled with kin selection were attributed to group selection. When kin selection came along, with its explicit quantitative models of relatedness - it more or less ate group selection's lunch. I expect a broadly similar phenomenon to take place in the realm of cultural evolution.

This picture of parallels between the sciences of cultural and organic evolution puts academic cultural evolution some 40 years behind the organic evolution. Other pointers suggest that sort of lag as well - for instance the poor understanding of symbiology. Of course, in some respects things are both more and less advanced. Cultural evolution still lags behind where evolutionary theory was the 1930s - in some respects - while a few individual pioneers have raced on ahead.

The good news is that cultural evolution seems to be slowly catching up. Science done on internet time looks a little different. In the last five years, the picture of the field has changed dramatically.

Peter Richerson and Paul Ekman: Evolution of human communication

Daniel Dennett - What is a meme?

Dennett explains the basics of memes - in 90 seconds.

Dennett - on how culture isn't just treasures.

Dennett explaining that we need to evolve "dinosaur" religions into birds.

George Williams on memes

George C. Williams was a meme enthusiast - though he didn't write a lot on the topic.

Here he is explaining one of his ideas:

The gene is a package of information, not an object. The pattern of base pairs in a DNA molecule specifies the gene. But the DNA molecule is the medium, it's not the message. Maintaining this distinction between the medium and the message is absolutely indispensable to clarity of thought about evolution.

Just the fact that fifteen years ago I started using a computer may have had something to do with my ideas here. The constant process of transferring information from one physical medium to another and then being able to recover that same information in the original medium brings home the separability of information and matter. In biology, when you're talking about things like genes and genotypes and gene pools, you're talking about information, not physical objective reality. They're patterns.

I was also influenced by Dawkins' "meme" concept, which refers to cultural information that influences people's behavior. Memes, unlike genes, don't have a single, archival kind of medium. Consider the book Don Quixote: a stack of paper with ink marks on the pages, but you could put it on a CD or a tape and turn it into sound waves for blind people. No matter what medium it's in, it's always the same book, the same information. This is true of everything else in the cultural realm. It can be recorded in many different media, but it's the same meme no matter what medium it's recorded in.

In cultural evolution, obviously, the idea of a coffee cup or a table is something that persists. The coffee cups and tables don't persist, they recur as a result of the persistence of the information that tells people how to make coffee cups and tables. It's the same way in biology: hands and feet and noses and so on don't persist, they recur as a result of genetic instructions for making hands and feet and noses. It's the information that lasts and evolves. Obviously, it's because of the physical manifestations of the information that we know about the information. Dawkins has had trouble in convincing people, and this stems from his thinking of the gene as an object — of emphasizing the importance of replication rather than of proliferation of information.

George C. Williams pioneered information-theoretic notions of genes - that eventually went on to influence Richard Dawkins and the other memetics pioneers.

Dominant and recessive memes

Just as genetics features dominant and recessive genes, memetics features dominant and recessive memes.

The basic idea of dominant and recessive genes is that:

• Variants compete;
• When two different versions are present at once, sometimes one consistently overshadows the other in terms of its effects.

This idea transfers seamlessly to cultural evolution. There's dominant memes, recessive memes, zygosity, complete dominance, incomplete dominance, and pathologies from double-doses of recessive memes.

For example, reef knots dominate granny knots. For another example most words in English dominate those in Esperanto.

Homozygousity is not a terribly useful concept in cultural evolution - but most of the rest of the associated concepts apply about equally well to both realms.

Tim Lewens on memetics

Tim Lewens is one of the surviving critics of memetics. His attacks on memetics still seem to feature in encyclopaedia articles - and so perhaps are worth rebutting. Here he is in a 2013 article:

A second, and closely related, criticism of memetics draws on the fact that while genetic replication allows us to trace a token copy of a gene back to a single parent, ideas are rarely copied from a single source in a way that allows us to trace clear lineages. Perhaps you learned the tango from several teachers, and your style has been influenced by watching expert dancers. There is no clear single origin for your “tango” meme. Within the realm of biological evolution, an understanding of Mendel's laws has been important in explaining some aspects of evolutionary dynamics. Mendel's laws rely on an understanding of genes as discrete, transmitted units. But if token ideas can appear in an individual by virtue of that individual's exposure to several sources, then it is unlikely that anything close to Mendel's laws will be discovered within cultural evolution. Such an objection need not be fatal for theories of cultural evolution in general, as we shall see, but it does threaten the tight analogy memetics draws between ideas and genes.

There are a few points to be made here:

Tracing DNA genes backwards to a single parent is also often not possible - due to meiosis. Meiosis means that gene sections come from an exponentially-increasing number of ancestors as you go backwards in time - a situation that closely mirrors what happens if you try and trace the ancestry of memes. You can often trace memes back to a single ancestor in the previous generation. Similarly, you can often trace DNA genes back to a single ancestor in the previous generation. This hardly seems like a major difference.

A lineage is defined to be the set of descendants of some ancestor. This concept is equally applicable to both cultural and organic realms. The idea that you can't find "clear lineages" in cultural evolution is complete bunk.

Lewens invokes the idea of blending influences from multiple individuals. However, much inheritance in culture does not involve blending. Instead, it's simple copying from a single parent. Blending inheritance is not the rule. Tim's claim that: "ideas are rarely copied from a single source in a way that allows us to trace clear lineages" is wrong. Look at modern peer-to-peer networks, for instance. High fidelity copying with uni-parental inheritance everywhere. Such high-fidelity cultural copying is extremely common these days.

Also, much alleged blending inheritance turns out not to involve blending at all. My gut bacteria are a kind of "blend" of those of thousands of other people. However if you look closely at the genes involved, it's mostly simple uni-parental inheritance that's involved. Tango involves many cases that are like that. There are many behaviours copied when learning to tango - and often they are copied from specific individuals.

However, blending during cultural evolution does sometimes happen. The thing is, such blending takes place in the organic realm too. It is better thought of as blending selection rather than blending inheritance.

Many individuals per-generation may indeed influence tango performance. However, many individuals per generation may also influence a tasty moth's attractiveness to birds. Tasty moths come to resemble toxic moths because of their DNA - not because of cultural influences. The blending of influences from multiple models in a single generation is a ubiquitous phenomenon in organic evolution.

As for Mendel's laws:

• Law of Segregation (The "First Law") - doesn't apply to most memes. Doesn't apply to most DNA genes either.
• Law of Independent Assortment (The "Second Law") - technically wrong for DNA genes and memes - Mendel missed linkage.

Mendel's second law applies about equally to memes and genes. Linkage applies to genes and memes too. The first law doesn't apply to a lot of memes. However, it doesn't apply to a lot of DNA-based organisms either. Mendel's first law has narrow applicability. The laws have little to do with the link between genes and memes. The topic seems to be an irrelevant one.

After all of these points are considered, not too much remains of the original objection.

It's true that organic evolution features a phenomenon whereby single nucleotides are almost always represented in at least one parent in the previous generation - whereas that isn't true of cultural evolution. Indeed, cultural evolution doesn't really involve nucleotides at all...

It's true that cultural evolution is more likely to involve extrapolation, interpolation, medians - and other advanced types of recombination. Recombination in brains has some more possibilities than recombination inside cells does. Memetics doesn't deny this. Blending inheritance happens inside minds - and not inside cells - but... so what? Memes aren't like genes in every single respect. Nobody ever claimed that they were. Advanced types of recombination really have little impact on the link between memes and genes - which is based on both being small bits of inherited information that evolve.

References

• Lewens, Tim (2006) Organisms and Artifacts: Design in Nature and Elsewhere. [criticism]
  
• Lewens, Tim (2006) Darwin. [criticism]
  
• Lewens, Tim (2007) Stanford Encyclopedia of Philosophy section on cultural evolution. [criticism]
  
• Lewens, Tim (2013) Cultural Evolution: Integration and Skepticism. Oxford Handbooks Online. [criticism]
  

Memetics on Google Scholar

Following up on my last blog post, I checked Google Scholar on "Memetics".

This is an update on my "Memetics death report exaggerated" article - from 2008.

Google Scholar shows the following growth for memetics papers:

Growth in "memetics" papers over time

Compared to "cultural evolution", memetics shows similar growth, but starting later and with significantly less popularity.

Genetics is less popular than evolution too - but by less than 2:1. However memeticsis less popular than cultural evolution by more than 5:1. Even after accounting for the lack of interest in cultural evolution, memetics is an under-studied area.

Here's my graph data:

1985 - 1 1986 - 1 1987 - 3 1988 - 2 1989 - 3

1990 - 6 1991 - 3 1992 - 7 1993 - 3 1994 - 7 1995 - 16 1996 - 32 1997 - 43 1998 - 103 1999 - 126

2000 - 126 2001 - 206 2002 - 234 2003 - 225 2004 - 284 2005 - 313 2006 - 346 2007 - 469 2008 - 484 2009 - 557

2010 - 628 2011 - 731 2012 - 488 2013 - 90

Here's last year's plot.

Is cultural evolution a "degenerative research program"?

Massimo Pigliucci recently wrote:

This is the section in which he cites the now classic work of people like Cavalli-Sforza, Feldman and others on gene-culture co-evolution. The thing is, if we are meant to take that (interesting, pioneering) work as a way to theorize about cultural evolution, we are at a dead end. Most of those papers are from the 1970s and ‘80s, with very little having been done since. That approach looks increasingly like what philosopher of science Imre Lakatos famously called a “degenerative” research program, i.e. an approach that seemed once fruitful but that has since ceased to bear fruits.

Unlike Massimo, I am familiar with much of this literature. Massimo is wrong about this. Instead, I agree with this perspective:

For those who are interested in extending evolutionary explanations to a very broad range of phenomena that include human culture, these are very exciting days. We are seeing a flood of fascinating experimental results as well as rapid development in the underpinning theories. One could well say that we are witnessing a major transition in how humanity understands the world and itself.

To help calibrate, I checked with Google Scholar on "cultural evolution". It shows this growth:

Growth in "cultural evolution" papers over time

Of course most scientific fields are growing, but the field of cultural evolution is exploding - and, yes, some of those papers are doing meme frequency analysis based on population genetics.

Indeed, free data sets relating to cultural phenomena - such as those produced by MemeTracker, Google, YouTube, IBM, BlogRunner, governments and others - has led to a modern explosion of such papers.

Here's my graph data:

1970 - 183 1971 - 217 1972 - 221 1973 - 234 1974 - 240 1975 - 299 1976 - 281 1977 - 334 1978 - 382 1979 - 356

1980 - 403 1981 - 403 1982 - 391 1983 - 435 1984 - 418 1985 - 413 1986 - 528 1987 - 561 1988 - 548 1989 - 611

1990 - 641 1991 - 689 1992 - 760 1993 - 712 1994 - 773 1995 - 784 1996 - 937 1997 - 1010 1998 - 1100 1999 - 1270

2000 - 1400 2001 - 1500 2002 - 1770 2003 - 1960 2004 - 2170 2005 - 2430 2006 - 2630 2007 - 2970 2008 - 3260 2009 - 3550

2010 - 3490 2011 - 3740 2012 - 3960 2013 - 855

For the corresponding results for "memetics", see here.

What are inheritance and copying?

Copying is one of the foundational principles of universal Darwinism. The others main ideas involved are: variation, selection, and cumulative adaptation.

"Inheritance" and "copying" are basic concepts, which I often just assume that people understand. However, a lot of ink has been spilled over the issue of what they mean. In particular, whenever I use the term "copying" in this context, there's often someone who objects to my usage, claiming that the word "copying" implies high fidelity. Some of the confusion in the area stems from using the terminology of replication - which really does have implications of high-fidelity copying - in everyday use.

Sylvain Magne recently claimed that the issue of high-fidelity copying is "one of the major challenges that memetics is facing". I've written about he issue of high-fidelity copying before. I don't think it is a particularly complex or difficult issue. Surely it is only a challenge to memetics in the eyes of its critics.

However, I do think that a proper approach to universal Darwinism should define what it means when it talks about "copying", "inheritance" or "reproduction". So, this post will do precisely that:

"Copying" is an ordinary dictionary word - but if you look at dictionaries and popular definitions of the term, they are often completely useless for technical work. Look at Wikipedia, for an example of the muddle surrounding the term.

I think the best way to define "copying" for technical work is using concepts from information theory and the theory of causality. Information theory was pioneered by Claude Shannon, and the theory of causality was pioneered by Judea Pearl.

To say that A has copied from B makes two main claims:

• That A has become more similar to B in some respect;
• That the increased similarity between A and B was caused by A's influence on B.

The first claim is simpler - A and B have increased their Shannon mutual information associated with some measurable aspect or trait.

The second claim is more complex - since it involves the idea of causality. Causality is a difficult concept:

We usually think we know that causes come before events that they cause - and not the other way around. However, we also know that the laws of physics exhibit microscopic reversibility. This means that either causality has to do with large scale thermodynamics and increases in entropy - or our conventional conception of the past causing the future is wrong. Physicists are generally more comfortable with the latter notion. For example Feynman diagrams feature particles that travel backwards in time. This just shows that causality is a more complex topic than it may - at first - appear to be.

I'm mostly just going to defer to Judea Pearl's book when it comes to explaining what "causality" means. However, I will make a few comments:

The idea that B copied from A can be dealt with scientifically. The main hypotheses that can account for increased similarity between A and B are:

1. B has become more similar to A because of causal influences from A;
2. A has become more similar to B because of causal influences from B;
3. B has become more similar to A because of causal influences from C.
4. B has become more similar to A by chance;

These are all scientific hypotheses that make predictions. The first hypothesis suggests that changes in A might have been been copied into B. If you can repeat the experiment, change A, and then see that B copies that change, then this counts as evidence against hypotheses 2 and 3. Dawkins (2004) proposes precisely this test, saying:

For an operational criterion for whether an entity is a true replicator, ask what is the fate of blemishes in entities of this class.

If you repeat such an experiment on multiple occasions - and if the results are consistent - that counts as evidence against hypothesis 4.

Sometimes you can't rerun the experiment - e.g. because it involves a unique historical event. However you can usually model or simulate it - and then apply the same process to the model.

There are sometimes other ways of exploring the issue of whether A copied from B. For example, you can look for possible Cs, which A and B both copied from. Or you can look at how and when A and B previously interacted.

These two ideas - Shannon mutual information and causality - are the main concepts you need to put the ideas of inheritance and copying on a firm theoretical footing - for use in Universal Darwinism.

The 2008 paper In defence of generalized Darwinism makes the same point as follows:

A number of authors have developed and refined the definition of a replicator. An emerging consensus argues that replication involves a causal relationship between two or more entities, where there is substantial similarity between the original and replicated entities, and where information concerning adaptive solutions to survival problems is passed from one set of entities to another (Sterelny et al. 1996; Godfrey-Smith 2000; Sperber 2000). The definitional characteristics of causality, similarity and information transfer are common to these accounts.

There's no reason to introduce the concept of high-fidelity copying - unless you want to get into the issue of the conditions required for cumulative adaptive evolution.

On informational culture

One of my more contrarian positions is that I don't really like informational conceptions of culture - positions that treat culture as information. Most researchers in the field have adopted what they call "ideational" conceptions of culture. Aunger, Durham, Boyd and Richerson and Mesoudi are among the researchers who approve of the culture-as-information concept.

I do agree that the informational basis of cultural transmission is an important concept - and that we need terminology to describe it. However, we have some fine terminology developed for that specific purpose: the terminology of memetics: "memes", "memeplexes", "meme pools", etc. Memes are the informational basis of culture. However there's more to culture than memes. There's meme products, namely: artefacts and behaviours. If you "spend" the word culture on its informational aspects, you need new terminology to describe meme products and the union of memes and meme products. I think it's best to call the umbrella category containing memes and meme products by the term "culture". Including artefacts and behaviours seems more consistent with everyday usage - and with historical usage of the term, dating back to Tylor in the seventeenth century.

This use of terminology to distinguish cleanly between the informational and non-information aspects of culture is one of the nice things that memetics inherits from evolutionary biology. There there's "genes" and "gene products". "Genes" refers to the heritable information, and "gene products" are everything else affected by them. The terminology of memetics applies this exact same split to the cultural realm.

From the perspective of culture-as-information, the term "gene-culture co-evolution" makes sense. However, from my perspective, it's an oxymoron. You can have "gene-meme co-evolution" or "organo-cultural co-evolution" - but "gene-culture co-evolution" mixes up different types of thing - and sounds stupid.