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Myths of Evolution

This serial ran from January 15th to February 26th 2009, in six parts. Originally written as a throwaway Focus essay, it rapidly became apparent that it would work better as a serial. The purpose of the exercise was to identify specific stories that have been used to present various evolutionary theories in the popular media of the last 150 years. Most of these stories are metaphysical in nature, and for each such "myth", an alternative spin is offered to show that while science is in principle neutral, the way it is presented is rarely free of bias. Each of the parts ends with a link to the next one, so to read the entire serial, simply click on part one, below, and then follow the "next" links to read on.

Here are the six parts:

  1. Scientific Metaphysics
  2. The Ladder of Progress
  3. Only the Strong Survive
  4. The Selfish Gene
  5. Kin Selection
  6. Survival of the Fittest

This serial commemorates the bicentennial of Darwin's birth, and the 150 year anniversary of the publication of On the Origin of Species by Means of Natural Selection. It is dedicated to the memory of Stephen Jay Gould.

A new book, The Mythology of Evolution, inspired by this serial is due from Zer0 Books in 2012.


Myths of Evolution (6): Survival of the Fittest

Dropletworld Finally, perhaps the most famous myth about evolution: “survival of the fittest”. This is often taken to mean that “only the strong survive”, which I discussed previously, but this radically understates the mechanics of the processes of natural selection. It is often pointed out that this phrase – “survival of the fittest” – is a tautology, and indeed, this criticism is correct. Since “fittest” means “best adapted to survive”, this claim is entirely circular. This isn't an argument against the various theories of evolution, per se, since these do not rely upon this tautology, but it invalidates a lot of lay thinking on the matter.

All of the previous myths I have examined relate in some manner to this central myth of “survival of the fittest”: the idea that “only the strong survive” is directly related, erroneously equating 'strength' with 'fitness'. The ladder of progress (incorrectly) assumes the winnowing of the simpler forms on the mistaken belief that 'more advanced' equates to 'fitter'. The “selfish gene” applies the “survival of the fittest” myth to genetics, arguably obscuring what is valuable in the gene-centric view. Kin selection correctly observes that co-operation is an advantage, but tries to shoehorn this into the “survival of the fittest” paradigm, mangling its meaning. All these various myths can be arguably traced back to the application of Darwin's ideas to economics by Herbert Spencer, who first coined the phrase “survival of the fittest”, a view that had been distorted by his prior metaphysical belief in the primacy of progress.

The myth “survival of the fittest” seems to  say: survival is a game and it is won by those who are best at playing it (the “fittest”). But this is supposed to be a story which encapsulates what evolutionary theories teach us about natural history, and in this role it is remarkably ill chosen. Competition for resources and the struggle for survival are part of natural history, and one of the driving forces in natural selection, but theories of evolution demonstrate that competition for mates is just as important as competition for survival in driving the selection process (Shall we dub this “propagation of the sexiest”?). In many social animals the ability to co-operate to protect the young is more important than intra-species competition in terms of the continuation of the species - does “survival of the fittest” really encourage us to consider co-operative behaviours as advantageous? On a wider geological scale, punctuated equilibrium shows that when the conditions change what once was  “fittest” becomes extinct - an aspect of lottery entirely elided in the idea of “survival of the fittest”. Except in the tautological sense that “fittest” means “best adapted” this myth is rather empty of applicable meaning.

In recasting this core myth into a new form, we can draw upon the new stories I have been suggesting. The chain of inheritance (replacing the ladder of progress) stresses the idea that every living species is connected to the beginning of life by an imaginary tether along which various beneficial abilities are inherited, since advantages persist (replacing the selfish gene). Those animals which live today are here in part by luck (or fate, for those whose metaphysics lie in this direction), and in part because of highly adaptable ancestors that thrived when other species became extinct during times of extreme upheaval: this is the survival of the adaptable (replacing the idea that only the strong survive). Finally, for those many species fortunate enough to have inherited a trust mechanism from their ancestors – and this appears to be all mammals and birds, as well as many reptiles, fish and even (in a very different manner) some insects – future survival depends in part upon co-operation, since trust is an advantage (replacing kin selection).

These new myths don't suggest a story in which “survival of the fittest” would be the apposite adage. They rather suggest that the history of life on our planet reflects a refinement of possibilities. This is not to deny that competition for resources or the background struggle for survival are a key part of natural history, nor that natural selection can be a harsh process, but focussing solely on these aspects of the history of life risks radically curtailing the scope of our understanding seeing only the warp of the tapestry of life, and missing the weft. The fox preys upon the rabbit, but in doing so the possibilities inherent in rabbits become refined and in reacting to these refinements, the possibilities of the fox are also gradually refined.

From the raw experiments born of the exuberance of life come new possibilities – such as the potential of the eurkaryotic cell created from the co-operation of single-celled bacteria (endosymbiotic theory) , or the dramatic potential of cell differentiation this created (the likely cause of the Cambrian explosion). Life has sprung into diverse existence, and been savagely curtailed by disasters and extinctions, but throughout the unfathomable duration of geological history it is clear that evolution has created new possibilities, new and amazing forms of life, as well as novel ways for these creatures to interact, such as the potential for co-operation on a cellular level (endosymbiosis) and a macroscopic level (trust). Seen through this lens, our evolutionary history tells the story of the gradual refinement of the possibilities of life – from which process emerges all the many living things of our planet, including you and I, and everything to follow.

Alternative myth: Refinement of Possibilities

A new serial begins in April.


Deconstructing Temperament

Continuing on from my attempts to devise a hypothetical underpinning for Flow, I now present the equivalent speculations for Temperament Theory.

Roots

This post will mean nothing to you unless you are familiar with either Temperament Theory or Myers-Briggs Typology. This post builds upon various previous pieces posted here, including:

This isn’t the first time I have attempted to tie Temperament Theory to neurology. If you are pretty clued up on the subject, you can read my amusing first attempt at speculating in this area, based solely on my understanding of the functions of digital neural networks.

Disclaimer

The idea that people type perfectly into fixed patterns is not something most psychologists who work with Temperament Theory uphold. Rather, we all express these different patterns at different times, and to different degrees. But we can usually pick out a greater influence of one or more patterns over the others in the case of individuals. In this piece, I suggest that these behavioural patterns can be linked to a neurobiological substructure.

Rational (NT)

The Rational temperament is the easiest of the four behavioural patterns to link to neurobiology, since it is relatively clear that the elements of this pattern – precise abstract thinking, interest in efficient operations, pragmatism, focus on structure, problem solving – correlate with the actions of the decision centre of the brain (the orbito-frontal cortex), at least as a hypothetical assertion.

Since it now seems that areas of the brain vary in size according to the degree that they are used, it should be possible to test this claim by comparing the size of the orbito-frontal cortex in those who type as NT/Rational, to those who type weakly in this area.

Guardian (SJ)

Again, this one is not too difficult to speculate at the neurological level. The Guardian pattern is associated with organisations and logistics, the maintenance of procedures and systems, duty and trust, and goal-orientation. This strongly suggests a neural system linking the association areas (hippocampus) with the pleasure centre (nucleus accumbens).

Indeed, the Judging axis of Myers-Briggs (which is an aspect of the Guardian pattern), which is associated with goal-orientation seems to strongly correlate with increased reward (increased release of dopamine) from the pleasure centre.

The affiliative aspect of the Guardian pattern (belonging to organisations and identities) presumably relates to the social centre (hypothalamus), but again, linked to memory via the association areas. In other words: your memory tells you who and what to trust (based on your prior experience), and your hypothalamus thus generates trust and a sense of safety (belonging) when you are with those people you identify with.

Thus in the Guardian pattern established norms (learned by the association areas) create goals involving the maintenance of systems and execution of logistics, and these goals release dopamine, thus reinforcing those behaviours.

Artisan (SP)

Here, I have to take something more of an intuitive leap, but I believe the Artisan pattern can be understood in part through the mechanics of Flow I described last week. Since the Artisan pattern is process-oriented (expressed by the Perceiving axis in Myers Briggs, which becomes subsumed in the Artisan pattern in Temperament Theory), it seems reasonable to suppose that this behavioural pattern relates to the steady release of dopamine in the pursuit of uncertain outcome in preference to the pursuit of the goal itself. In other words: for people in whom the Artisan pattern is more strongly expressed than Guardian, taking actions is marginally more compelling than achieving goals. Perhaps it will transpire that the differential between the dopamine released during the pursuit of uncertain goals and the dopamine released on achieving a goal is less pronounced in the Artisan pattern than in the Guardian pattern.

The pattern itself is associated with the desire to have an impact through freedom of action, a concrete pragmatism, spontaneous creativity, hedonism, impulsiveness and sometimes compulsiveness. A weaker relationship between association areas and the pleasure centre, coupled with an increased influence of the sensory cortices (with their associated power to release dopamine via curiosity) may be a factor here.

Artisan is rendered as SP (Sensing-Perceiving bias) in Myers-Briggs terminology, but note that unlike the other Sensing pattern (Guardian, which is SJ – Sensing-Judging bias) there is no obvious role for the hypothalamus here. The Artisan pattern thus veers towards independent behaviour, in common with the Rational pattern (thus suggesting the basis of their common link, a focus on the pragmatic over the affiliative).

Idealist (NF)

Finally, the Idealist pattern is associated with abstract language use (in common with the Rational temperament), a search for meaning and significance, and a focus on motivations, with an emphasis on empathy and unity.

Sharing in common with the Guardian pattern the affiliative bias, it is likely that the social centre (hypothalamus) plays a role in this pattern, but whereas for Guardian I suggested a link between this brain region and memory (i.e. with the association areas), for Idealist this doesn’t seem to be the case. An Idealist is likely to feel a sense of unity with almost any person, which may reflect the role of the hypothalamus when it is involved in rather different neural connections. It is difficult not to suggest the mirror neurons as an element in empathy, and the parietal lobe has been linked with both mirror neurons and empathy, suggesting its involvement with this pattern.

A likely additional element is the fusiform gyrus, a part of the temporal lobe about which there is still some dispute, but which has been linked to both language skills and abstraction (as well as face and body recognition and the processing of colour information). Informally, I have observed a greater interest in colour among people who express Idealist, which might serve as an additional supporting factor, however tenuous at this point.

Summary of Components

Modern Temperament Theory works on the basis of three axes of comparison: abstract versus concrete language skills, affiliative versus pragmatic actions, and structure versus motive focus. Each of the four Temperament patterns is distinguished by these three axes, even though in principle only two would be required to generate four patterns.

Based upon my hypothesis above, the following links between these axes of distinction and various areas of the brain would be suggested:

  • Abstract: either decision centre/orbito-frontal cortex (in Rational) or language centre/fusiform gyrus (in Idealist) or both with different degrees of emphasis.

  • Concrete: either the various sensory cortices, or the memory association areas/hippocampus, or both (in both Guardian and Artisan).

  • Affiliative: hypothalamus (in both Guardian and Idealist), coupled either with the memory association areas (in Guardian) or empathy regions i.e. mirror neurons/parietal lobe (in Idealist).

  • Pragmatic: probably the orbito-frontal cortex (in both Rational and Artisan), either in isolation (in Rational) or in concert with the memory association areas/hippocampus (in Artisan).

  • Structure: either decision centre/orbit-frontal cortex (in Rational) or the memory association areas/hippocampus (in Guardian), or possibly both with differing degree of emphasis.

  • Motive: either mirror neurons/parietal lobe (in Idealist), or anticipation of reward in the context of the pleasure centre/nucleus accumbens, possibly with an adjunct role for the orbito-frontal cortex (in Artisan).

Of course, some of these correlations begin to look somewhat forced if the hypothetical mechanisms can be validated, but this was always likely to be the case in such a coarse-grained system.

This in turn allows us to suggest the equivalent substitutions for the Myers-Briggs axes as follows:

  • Introvert/Extravert: currently not covered in this hypothesis.

  • Sensing/Intuitive: identical the Abstract versus Concrete distinction, above i.e. memory association areas/hippocampus and sensory cortices for Sensing versus decision centre/orbito-frontal cortex and/or language centre/fusiform gyrus.

  • Thinking/Feeling: compounded from Pragmatic-Structure versus Affiliative-Motive, above, that is, decision centre/orbito-frontal cortex versus hypothalamus and/or mirror neurons/parietal lobe.

  • Judging/Perceiving: pleasure centre/nucleus accumbens, in two modes: goal-oriented (i.e. seeking maximum dopamine) in Judging versus process-oriented (i.e. seeking continuous supply of dopamine during pursuit of uncertain reward) in Percieving.

Notice how the correlations for the Myers-Briggs axis have little in common with the axes of comparison in modern Temperament Theory, reflecting the different assumptions behind both systems.

Conclusion

According to the hypothesis presented here, the following components represent the underlying elements of the neurobiological systems which in turn generate common recurrent patterns of observable behaviour reported by both Myers-Briggs typology and modern Temperament Theory:

  • Pleasure centre (nucleus accumbens)

  • Decision centre (orbito-frontal cortex)

  • Language centre (fusiform gyrus)

  • Association areas (hippocampus)

  • Sensory cortices

  • Social centre (hypothalamus)

  • Mirror neurons (parietal lobe et al)

As a game designer and not a neurological researcher, I am not in a position to investigate this further, but a research team consisting of both psychologists and neurobiologists should be able to investigate these claims, should anyone be sufficiently motivated to do so.

That just about does it for the speculative neurobiology for now. I'll try and get some specific games-related pieces onto ihobo in the near future.


Almost Recovered

Still quite far from a full health bar, but at least well enough to go back to work today. I've left a host of comments in response to various topics, so those of you who were waiting for a reply should find something interesting to chew over or disagree with. Have a great weekend, and I'll see you next week for "business as usual" here on the Game!


You Are Not Your Brain

Apologies for falling behind on the comments - I've been away in Prague on business. I'll catch up next week. As a partial reply to Scott's concerns about behavioural reductionism I would like to share this quote from a recent article in The Guardian (Saturday 27/12/08), by neuroscientist Stephen Rose:

However, it is not brains that have concepts or acquire knowledge. It is people, using their brains. To paraphrase the anthropologist Tim Ingold, I need legs to walk, but I don't say “my legs are walking”. Similarly, I need my brain to think, but it is I, not my brain, who does the thinking. Indeed, [Semir] Zeki gives the game away when he quotes Kant as saying “The Mind does not derive its laws... from nature but prescribes them to her” and goes on to say “he might as well have been writing about the brain”. No, no; the mind may need the brain, but it is not reducible to it, and we neuroscientists need to recognise our limitations. Of course, such reductionism is not confined to my trade (think of The Selfish Gene), but it is currently rampant among neuroscientists – as in the title of a recently formed Society for Molecular and Cellular Cognition.

To put it another way: you and your mind may be inseparable, but your mind and your brain are not the same entity. Your brain is the biological system you use to think, and the organ that co-ordinates your behaviour, but it is you that acts and not your brain.

Have a great weekend everyone!


Myths of Evolution (5): Kin Selection

Cleaner wrasse As with “the selfish gene”, kin selection is a valid perspective which manages to become misleading by missing the point of what it is trying to explain. The idea behind it, developed by J.B.S. Haldane and W.D. Hamilton in the late 1950's and early 1960's, is simply that the behaviour of a great many organisms include the risk or sacrifice of the individual for the benefit of relatives – for instance, alarm calling in squirrels (which puts the caller at greater risk from predators), or sterile worker bees who will never breed. According to conventional Darwinian thinking, natural selection should (supposedly) eliminate such behaviours (at least when considered from the gene-centric view), so kin selection was introduced to explain the apparent anomaly.

But there is no anomaly to explain here: the assumption that natural selection cannot favour the risk or sacrifice of individuals rests on a chain of inferences linking behaviour to strict genetics, which as already discussed is a flimsy argument. When we think of “advantages persisting” instead of “selfish genes”, it becomes clearer that co-operation will not be eliminated by natural selection – it will in fact be selected for whenever it is advantageous. As Peter Kropotkin observed in the 1890s, co-operation and mutual aid contribute significantly to the survival of species, since a group of animals can achieve more than the individual members can on their own. The rise of humanity as a species appears to have been significantly facilitated by its capacity to act as a group.

The power of co-operation even extends into the world of plants: Allen Herre and Elizabeth Arnold discovered that plants defend themselves from fungal infection by hosting a population of symbiotic fungal lifeforms (known as endophytes). Throughout the natural world, examples of beneficial co-operation – symbiosis – can be found. In almost every environment, one can find examples of genetically distinct organisms which co-operate, and thus gain advantages in survival and reproduction.

Furthermore, as Lynn Margulis has explicated, all multi-cellular life operates as a consequence of symbiotic co-operation between micro-organisms which have become so reliant upon one another that we mistake their colonies for individual animals. This viewpoint, which is referred to as endosymbiotic theory, originates in the work of the Russian botanist Konstantin Mereschkowski, who in 1905 observed that cell division in chloroplasts mirrored that in free-living cyanobacteria.

You and I are the product of co-operation between billions of cells (closely related to bacteria) which came together to act as one – the mitochondria (cellular powerhouse) and other organelles in each of your cells descend from bacteria which began to work closely together between 1.6 and 2 billion years ago. This astonishing evolutionary development, along with other symbiotic adaptations, have had as great a role in the development of life on Earth as competition between species.

On the macroscopic scale in which we are more familiar, the existence of social animals who co-operate for mutual benefit is another overt sign of the benefits of co-operation. Although it is misleading to conflate biological mechanisms with behaviour, the hormone and neurotransmitter oxytocin appears to be the constitutive mechanism by which trust operates. Almost all vertebrate species possess a chemically similar protein, which appears to have originally been involved in water regulation. From amphibians onwards, however, there has been a trend of increasing capacity for trust between animals – something we are most familiar among mammals, who form packs and other groups for mutual benefit, but which is also found in the flocking of birds, and even in reptiles and fish. Oxytocin and other related proteins also seem to play a critical role in the formation of families (a large quantity of oxytocin is released during childbirth), one of the most important survival benefits found in the natural world.

The extent to which co-operation affords advantage is apparent in the prevalence of mutual aid in the ocean. Coral reefs, which are nature's cosmopolitan cities, contain species such as cleaner wrasse (pictured above) and cleaner shrimp which remove parasites and dead tissue, even from within the mouths of other fish who do not harm the cleaning animal. Recent observations have shown dozens of sea snakes co-operating not only with each other but also with goatfish and trevally in an astonishing display of multi-species collaboration, dramatically depicted in the recent Planet Earth nature documentary. This is not to deny that competition between and within species does not also occur, nor to claim that savage acts do not happen in the natural world, but there is no reason (other than a metaphysical commitment) to deny that symbiosis and other forms of co-operation are also a key part of the story of life.

All of which goes to demonstrate why co-operation is so well represented throughout biology: it is an advantage so powerful, whenever species stumble upon it, it tends to persist. Rather than trying to shoehorn this observation into older models (as with kin selection), perhaps we might consider a new story which captures the incredible role of co-operation in evolution. Simple lifeforms co-operate because it's in their mutual benefit, and advantages tend to persist, but more complex life (such as humans) co-operate not just because it is immediately advantageous but also because we have inherited a biological mechanism which facilitates the formation of trusting relationships – primarily with our relatives, but potentially with anyone. The story that trust is an advantage runs contrary to the usual mythologies of evolution, but it is just as valid, and far more optimistic.

Alternative myth: Trust is an Advantage

Next Week, the Final Part: Myth #5: Survival of the Fittest