A microcosm of what went wrong with the industrial revolution: Calhoun’s Mouse Utopia experiment

Bruce G Charlton

Note: for convenience in referencing - this essay is cross-posted in a dedicated blog:
http://mouseutopia.blogspot.co.uk


The so-called ‘Mouse Utopia’ experiment was conducted from 1968 by John B Calhoun

http://en.wikipedia.org/wiki/John_B._Calhoun

Four healthy breeding pairs of mice were allowed to reproduce freely in a 'utopian' environment with ample food and water, no predators, no disease, comfortable temperature – a near as possible ideal conditions and space. What happened was described by the author in terms of five phases: establishment, exponential growth, growth slowing, breeding ceases and population stagnant, population decline and extinction:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf

Phase A - 104 days - establishment of the mice in their new environment, then the first litters were born.

Phase B - up to day 315 - exponential population growth doubling every 55 days.

Phase C - from day 315-560 population growth abruptly slowed to a doubling time of 145 days.

Phase D - days 560-920; population stagnant with births just matching deaths. Emergence of many pathological behaviours.

Terminal Phase E - population declining to zero. The last conception was about day 920, after which there were no more births, all females were menopausal, the colony aged and all of them died.

To summarise – when four breeding pairs of mice were allowed to reproduce under ideal ‘utopian’ conditions, the colony entirely ceased to breed after three years, and then went extinct.

Interpreting the demise of Mouse Utopia

The main fact about Mouse Utopia, was that despite everything possible being done to create ideal biological conditions; the mouse colony rapidly declined and became entirely extinct. This was a very surprising outcome, biologically; and implies that some very major factor about the basic requirements or behaviour of the mice was neglected.

The Mouse Utopia experiment is usually interpreted in terms of social stresses related to 'over-population'; that crowding generated pathological behaviours and a loss of the will to reproduce. But this seems, very obviously – I would have thought – an incorrect explanation; because 1. The mouse population never actually became crowded, 2. The suppression of breeding happened very quickly, and never recovered even after the population declined rapidly and crowding was reduced, and 3. the population rapidly became extinct.

Michael A Woodley suggests that what was going on was much more likely to be mutation accumulation; with deleterious (but not-individually-fatal) mutated genes incrementally accumulating with each generation and generating a wide range of increasingly maladaptive behavioural pathologies; this process rapidly overwhelming and destroying the population before any beneficial mutations could emerge to 'save' the colony from extinction.

So the bizarre behaviours seen especially in Phase D - such as the male 'beautiful ones' who appeared to be healthy and spent all their time self-grooming, but were actually inert, unresponsive, unintelligent and uninterested in reproduction - were plausibly maladaptive outcomes of a population sinking under the weight of mutations.

Why mutation accumulation?

The reason why mouse utopia might produce so rapid and extreme a mutation accumulation is that wild mice naturally suffer very high mortality rates from predation. Because wild mice are so short-lived, mice are not 'built to last' and have the reputation of being unusually-prone to produce new deleterious mutations (and are therefore extremely prone to cancer, and susceptible to carcinogens - which is why mice are used to test for carcinogens).

Thus mutation selection balance is in operation among wild mice, with very high mortality rates continually weeding-out the high rate of spontaneously-occurring new mutations (especially among males) - with typically only a small and relatively mutation-free proportion of the (large numbers of) offspring surviving to reproduce; and a minority of the most active and healthy (mutation free) males siring the bulk of each generation. Something similar is routinely done among laboratory mice - which are selectively bred using only the healthiest specimens - the sick and unfit mice being eliminated (usually killed, but at any rate not bred-from) with each generation.

However, in Mouse Utopia, there is no predation, and no artificial selection, and all the other causes of mortality (eg. starvation, disease, violence from other mice) are reduced to a minimum - so the frequent mutations just accumulate, rapidly, generation upon generation - randomly producing all sorts of pathological (maladaptive) behaviours.

The danger of mutational meltdown

Extinction due to relaxed selection leading to rapid mutation accumulation is called ‘mutational meltdown’.

It happens because, in addition to the problem of mutation accumulation by relaxation of selection, when a population has begun shrinking, there is an increasing danger of extinction due to a positive feedback cycle. Deleterious mutations accumulate so rapidly that they overwhelm a population before it can evolve an escape – as the population shrinks so it becomes less and less likely to ‘randomly’ generate a compensatory beneficial mutation that might recue it from extinction.

http://en.wikipedia.org/wiki/Mutational_meltdown

Mutational meltdown was first described as a threat for small populations of asexual organisms; later the phenomenon was described in sexual organisms, and then fond to occur in large populations. Therefore, mutational meltdown has gone from being a specific case to probably a universal possibility. And thus a possibility in humans.

The unusual twist with modern humans is that native populations in developed countries have begun falling (rapidly) over the past several decades apparently due to chosen sub-replacement fertility, and probably before mutation accumulation had reached a level sufficient biologically to suppress fertility.

In other words psychological factors have anticipated biological factors - and presumably both psychological and biological population decline will combine to increase the degree of reduced fitness resulting from mutation accumulation.

This will probably have increased the risk of mutational meltdown, and of extinction.

Modern England as Mouse Utopia?

If we look at the Mouse Utopia experiment and try to fit the history of modern England into it

http://en.wikipedia.org/wiki/Demographics_of_England

There could be an inflection point in 1921 when English population growth suddenly slowed - somewhat like the transition from Phase B to C in the mouse utopia graph (page 83)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf

Then the plateau Phase D - where births just replace deaths - was reached in the 1970s

http://en.wikipedia.org/wiki/Demographics_of_the_United_Kingdom#Vital_statistics_1960_.E2.80.93_2013

Which perhaps means the next phase would be the Terminal Phase E (among the native population - disregarding immigrants) with fewer births than deaths dwindling to zero live, births and escalating median age, until eventually ‘all’ women are aged beyond the menopause at which point extinction (of the native population) is inevitable.

Well, this isn't really comparing like with like! - and the whole picture is muddied by increasing medical capability and cossetting, which has radically reduced deaths from infectious disease (the main cause of mortality); and keeps infants and the elderly alive in circumstances which would previously have been fatal - but maybe gives us clues of what to look-out-for; assuming that the demise of Mouse Utopia was indeed substantially due to mutation accumulation.

Possible timescale for human extinction

If humans are recapitulating mouse utopia, what might be the approximate timescale for extinction?

As far as I can gather, mice are fully ready to reproduce at about 4 months, so the average generation time is probably about 5 months which is about 150 days.

So, starting with 104 days as zero - when reproduction in Mouse Utopia began; we can convert the above timings into mouse generations

Phase B exponential growth doubling every 55 days lasted 201 days, = 1.3 mouse generations.

Phase C exponential growth doubling every 145 days lasted a further 245 days = 1.6 mouse generations.

So population growth phase in utopian conditions lasted only 3 mouse generations.

Phase D of population stagnation phase lasted a further 360 days = 2.4 mouse generations

Therefore, Terminal Phase E the last conception (and de facto inevitable extinction) was 816 days after breeding commenced = 5.4 mouse generations.

Human generations are conventionally 25 years, although these have slowed to about 30 years in Western countries in the past several decades - but let us therefore give two values - one for 25 year, and the other for 30 year human generations.

If we start at 1850 as the date when the Industrial Revolution seems to have become certainly established and child mortality rates began to drop rapidly (from more than 60 percent to about 1 percent), and start counting generations from that point, and if humans were made like mice (which they are not!)...

We would then predict that human population growth phase (B & C) would last three generations up to 1925-1940

And the stagnation phase (D) for another 2.4 generations - with 5.4 human generations taking us up to 1985-2012.

Well, clearly English people did not stop conceiving four years ago, because babies are still being born to native English - albeit not at a high rate!

I have guesstimated above that the English situation was that the slower growth Phase C began in about 1920 (not about 1880) and the plateau phase began in about 1970) not 1930-ish

So maybe England is lagged about 40 years (or about 1.5 generations) behind Mouse Utopia , because 1. we are not mice, and 2. our mouse utopia emerged only incrementally – moving from the upper to the lower classes; and was probably not complete until about 1950.

So we do not need to worry about mutational meltdown and de facto extinction (i.e. the final English child of English-descended parents being conceived) for, oh, another thirty or forty years!...

Longevity versus fitness

In the late phases of the mouse utopia experiment the birth rate dwindled to zero - but there was a plateau phase when the population numbers remained approximately static because the fewer mice were being born but more mice were living to an extreme old age – a lifespan of four years and longer, which is considerably older than mice would expect to live in the wild.

Yet these mice were grossly abnormal, indeed pathological, in their behaviour. - in particular suffering what might be termed psychiatric abnormalities that impaired social interaction (and reproduction) including a strange narcissism in some male mice (the 'beautiful ones') which looked like superb physical specimens but did not mate.

So we find on the one hand a combination of evidence of cumulative disease, initially manifested in the realm of behaviour - yet on the other hand an ageing population with some animals having a very long life span.

My interpretation is that an increasing average lifespan cannot be interpreted as improving fitness - indeed increasing lifespan is compatible with a severe reduction in functional behaviour; especially when functionality is defined 'biologically' in terms of reproductive success (having sufficient viable offspring to maintain population numbers, and potentially amplify the population when conditions permit).

In Britain in recent decades there has been a large increase in average lifespan (among the native population), including several-fold increases in the length of survival of many groups of ill people. For example, elderly people with moderate to severe dementia may now live for many years, whereas thirty or forty years ago such a diagnosis was regarded as being rapidly fatal within months and less than two years. (And taking into account that modern English average life expectancy is about 80 years – an age at which about 20 percent of people have measurable dementia).

There is no doubt that modern people have been, and are being, misled by the increase in lifespan - and superficial appearances of youthfulness - into assuming that population health is improving; when in biological terms what matters is the ability to survive and reproduce under given conditions. Only if modern people - in particular those of reproductive and productive age - were put into the same kind of harsh, high mortality-rate environment that people of the past lived-in, would we know whether they really do have better functionality.

For example, in hunter gatherer societies those who lack mobility will, sooner or later, necessarily be left to die. In agricultural societies, the struggle for survival was extremely severe and the shortage of food, poor housing, and high prevalence of severe infectious diseases meant that the mortality rate among the elderly was much higher.

But modern societies shelter pretty much everybody from exposure to extreme heat or cold, dehydration, starvation, epidemic infectious disease and violence; plus there are several life-extending treatments of chronic medical conditions (such as high blood pressure) which would soon cripple or kill without continued medication and management.

Therefore, many people of much-reduced functionality who would been unable to survive in historical societies, are currently kept alive for many extra decades in modern societies - with all appearances of reasonably good health... except for behavioural pathologies and sub-fertility.

My point is that modern people may be much less biologically fit than they think they are; and that if societal conditions reverted towards those of historical agrarian societies, or hunter gatherer conditions, their low fitness and inability to survive would become very obvious.

Perhaps the increasingly elderly individuals of the terminal phase of mouse utopia may have congratulated themselves on the success of the experiment, and that mice had attained a more comfortable and compassionate level of social organization than in any previous society.

And then they died out; every last one of them.

Nonetheless, I draw the following lessons.

1. Assuming the decline and extinction of mouse utopia was due to mutation accumulation leading to mutational meltdown - then it happened very quickly indeed: only 5.4 mouse generations to the final conception, with half of that being stagnation.

2. The decline in rate of population increase after only 1.3m mouse generations suggests that the effect of relaxed natural selection and mutation accumulation leads to genetic damage immediately, in the very first generation.

3. Although humans (maturing over 14 years and with a natural life expectancy about 70 years) are built to last longer than mice (maturing over 4 months and living about 2 years) - this may mean that humans are actually more vulnerable to mutation accumulation - because we have a more prolonged and multi-phasic development and depend on extremely-complex brains supporting extremely complex behaviours; which depend on many genes to create and to sustain. Complex social and sexual adaptations are, in other words, large mutational targets – susceptible to damage from many mutations.

4. In mouse utopia, the mouse environment, shelter, food, hygiene etc were all managed by humans - and did not depend on the mice doing anything much for themselves except eat, sleep, fight, groom and reproduce (until they altogether lost interest in sex) - but humans depend on other humans for survival. But when the human population is damaged from mutation accumulation, there will be no external experimenters to ‘look after’ the increasingly-dysfunctional humans – and this will tend to destroy the 'utopian' environment. In other words, there will be a combination of an increasingly dependent population with a reducingly-capable population.

If this destruction is severe enough and comes early enough- then mutational meltdown will be avoided; because harsher natural selection (from the less capable ‘caring’ population) will purge the mutationally-loaded population to prevent it from breeding (and worsening the problem). But if there is a generational lag - and utopia is maintained for sufficiently long that further mutational damage to younger generations continues to accumulate rapidly - then this will hasten the meltdown and extinction; because by the time utopia comes to an end, the younger generations will be unfit to survive the harsher conditions which are the best they can themselves manage.

That is, the younger generations will become too unfit even to care for themselves at a bare minimum level while also being able to reproduce with genetically-viable offspring, and to raise them to independence – at which point extinction is inevitable. The ‘plateau’ phase is when a generation is born that can just-about keep itself alive and functioning, but not able raise any of its (even less-fit) offspring. Eventually, a generation is born that is not even capable to sustaining itself, and the die-off will then be very rapid.

What signs should we look for in monitoring mutation accumulation?

The first signs of mutation accumulation would probably be de-differentiation/ loss of adaptations - especially in social and sexual functioning. These would affect general intelligence 'g' (because g is a fitness measure), and adaptive social and sexual functioning (because these are subtle/ advanced adaptations which are damaged by even slight illness, intoxication, and functional or structural brain impairments).

http://iqpersonalitygenius.blogspot.co.uk/2012/08/objective-and-direct-evidence-of.html
http://iqpersonalitygenius.blogspot.co.uk/2014/03/further-evidence-of-significant-slowing.html

I think evidence consistent with both lowered intelligence and also impaired adaptive social functioning can be observed in the report of Mouse Utopia. The reduced fertility in Mouse Utopia is perhaps also related to impaired drive/ motivation - as well as ineffective drive/ motivation (due to loss of functional adaptations).

I general, I think loss of adaptive functionality is what should be looked-for with mutation accumulation (i.e. adaptive behaviours knocked-out or damaged or distorted) as the first and most sensitive changes; rather than weird new behaviours. Specifically:

1. The social domain - first subtle, then gross impairments of adaptive social interactions

2. The sexual domain - first subtle, then gross impairments of adaptive sexual interactions

...bearing in mind that 'adaptive' means tending to enhance reproductive success.

I suggest social and sexual functioning, since these are the areas which I think are the most sensitive to brain impairments; at least that seems to be the situation in neurological and psychiatric disease.

My observation has been that when there is almost any significant degree of neurological or psychiatric disease, even the slightest; social and sexual domain functioning can usually be detected as having been impaired, by those who best knew the patient before he suffered illness.

Psychiatric aspects of Mouse Utopia

In The Narrow Roads of Gene Land Volume 2, the great evolutionary theorist WD Hamilton partially described that world in a chapter entitled The Hospitals are coming, and that is perhaps a good starting point - the idea that everyone will be damaged and most will be sick, in one way or another; so that life will resemble a hospital in which (some of) the less-sick (or the damaged but not-yet sick) tend the more-sick, as best they may - in intervals between doing whatever it takes to stay alive.

This is not by any means an unusual or unprecedented situation for humans through much of the history of the species. For much of the time, Malthusian mechanisms have been in force, and populations have been limited by various combinations of starvation and infectious disease. Infections - in particular - have sometimes been endemic at a high prevalence, so that the majority or even all of the population might be suffering from, be affected by, some chronic parasitic disease (malaria and bilharzia are examples) - but at a relatively low degree of severity.

And with respect to the Mouse Utopia society being a Hospital, it is important to recognize that much of the pathology will be psychiatric rather than physical - this can be seen from the fact that the problems of the original Mouse Utopia were most behavioural rather than physical; and it follows from the fact that the highly complex human brain is exceptionally sensitive to random mutational damage.

Intelligence is probably damaged by mutation accumulation in an incremental and quantitative fashion - the more mutations, the more the lowering of intelligence. Therefore, decline of intelligence as mutations accumulate is likely to be relative smooth (rather than step-like). But intelligence is 'general' intelligence, and is unusual in being a general attribute of cognitive function – probably sustained by small effects of a large number of individual genes. By contrast, most psychological functions are specific; and genetic damage is likely to be more qualitative and either step-like, or all-or-nothing.

What I think would happen, is that accumulating mutation damage would most likely show-up as varieties of specific brain functional damage leading to a wide range of specific behavioural impairments of a social and sexual type (differing between individuals due to random mutations striking unpredictably at a wide range of individual genes) - in a context of progressively declining intelligence.

The kind of damage I am talking about represents a decline in ‘fitness’ – ie. a decline in the functional adaptation of the human organism to its environment (its sexual, social and surrounding environment): a loss of effective functionality. This represents a decline in absolute fitness, but not just relative fitness. It is a also a decline in group fitness - ultimately in species fitness.

If fitness is measured in terms of the capacity to raise sufficient viable offspring in a given environment; then the sexual and social changes induced by mutation accumulation will be such as to reduce the probability of doing this: partly by damage causing reduced brain processing speed and efficiency (detectable as reduced intelligence) and partly by damage causing specific functional impairments (detectable as sexual and social pathologies).

These impairments would presumably include a decline in motivation – reduced motivation to engage in effective reproductive behaviours, reduced interest in sex liable to lead to reproduction, reduced motivation to procreate, to care for and rear children etc. There is certainly abundant evidence of such changes in modern developed societies, such as England.

In sum, in a broad-brush interpretation of the evidence, it looks very much as if England specifically, and all other developed nations to a greater or lesser extent, are recapitulating the Phases of Mouse Utopia – leading towards extinction, or something close to it.

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Acknowledgements: It was Michael A Woodley of Menie who informed me of the Mouse Utopia experiment, and made the interpretation of its outcome in terms of mutation accumulation.

If we consider the scenario of Mouse Utopia - i.e. a massive reduction in human fitness due to mutation accumulation due to the removal of the main mechanism of generation-by-generation, mutation-purging natural selection (mainly the reduction of average child mortality from probably more than fifty percent to one or a few percent) - then there seems little or no grounds for realistic hope of avoiding a mega-death outcome.

(...Indeed, not merely mega- but a giga-death outcome, involving not just millions but billions of humans - because there are currently about seven billion humans compared to the recent historical global population of about one billion - and the Mouse Utopia scenario predicts that human fitness will drop below historical levels; presumably implying a lower than historical population. )

One particularly worrisome aspect is that the mutation driven incremental decline of human capability (due to an increase in human pathology) creates a positive feedback situation in which humans presumably would get less-and-less-capable of solving the multiple damaging consequences of mutation accumulation; including the problem of mutation accumulations itself.

This, at least, seems almost inescapable from the perspective of individual level selection; but if group selection mechanisms are real and applicable (as I believe they are), then it may be that behaviours will emerge that tend to counteract mutation accumulation, and avert the mutational meltdown positive feedback cycle.

But group selection is rather poorly understood, and perhaps works by multiple pathways. At any rate, by comparison with individual-level selection, group selection would appear to be ('as if) goal-directed, cognitive in nature, altruistic, and with foresight to look beyond short term individual reproductive disadvantage to long term group genetic benefit.

(Group selection may actually, or may not, actually be these things - teleological, cognitive, altruistic, predictive - but at any rate, this is how it would appear to us.)

So group selection might lead to a variety of quasi-purposive mutation-purging, fitness enhancing outcomes. These would not, of course, necessarily be conscious - indeed would likely be more effective if unconscious.

Possible examples might be an instinctive self-elimination of heavily mutated individuals from reproduction - varieties of genetic suicide. So, ordinary individual selection might tend to reduce reproduction of heavily mutated individuals due to them suffering from the effects of pathology - but in addition there might be some kind of system of internal monitoring of mutation load which made heavily mutated individuals 'give-up', lose interest in reproduction, avoid reproduction - perhaps at extremes allow themselves to die from starvation, infection or some other cause?

This would amount to a kind of apoptosis at the organism level (apoptosis is the biological process of cell-suicide, which may be triggered in genetically-damaged cells - for example to reduce the incidence of cancers). 

Alternatively, group selection may lead to the emergence of a higher incidence of the kind of human individuals who - by their dispositions and behaviours - have the best chance of solving the mutation accumulation problem in some way. For instance, it might lead to an increased number of problem-solving

WD Hamilton believed-in and wrote about such mechanisms of positive self-elimination, and argued that their existence is theoretically-predicted as well as consistent with some observation - so we should not regard them as implausible - even though they not well understood, and hard to discriminate from the passive consequences of mutational damage.

(Of course, group selection is not - contrary to some views - nicer than individual level selection; because group selection involves in some way the sacrifice of the individual for the genetic benefit the group.)

Nonetheless, if group selection is active, a range of such possibilities may already be at work, or may become more powerful - and this may affect the development and outcome of the Mouse Utopia scenario to a greater or lesser extent.  


Note: Some of these ideas were developed in conversation with Michael A Woodley of Menie, to whom acknowledgement and credit is due. 

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Current information on the rate of mutation and the fraction of sites in the genome that are subject to selection suggests that each human has received, on average, at least two new harmful mutations from its parents. These mutations were subsequently removed by natural selection through reduced survival or fertility. It has been argued that the mutation load, the proportional reduction in population mean fitness relative to the fitness of an idealized mutation-free individual, allows a theoretical prediction of the proportion of individuals in the population that fail to reproduce as a consequence of these harmful mutations. Application of this theory to humans implies that at least 88% of individuals should fail to reproduce and that each female would need to have more than 16 offspring to maintain population size. This prediction is clearly at odds with the low reproductive excess of human populations. Here, we derive expressions for the fraction of individuals that fail to reproduce as a consequence of recurrent deleterious mutation (ϕ) for a model in which selection occurs via differences in relative fitness, such as would occur through competition between individuals. We show that ϕis much smaller than the value predicted by comparing fitness to that of a mutation-free genotype. Under the relative fitness model, we show that ϕ depends jointly on U and the selective effects of new deleterious mutations and that a species could tolerate 10’s or even 100’s of new deleterious mutations per genome each generation.

Yann Lesecque, 

Peter D. Keightley, 

Adam Eyre-Walker.  

A Resolution of the Mutation Load Paradox in Humans. Genetics 2012; 191: 1321-1330.

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I am not suggesting that the above paper is the last word - far from it. Its conclusions require modification in light of some important features the authors have neglected. 

However, the basic point is that - according to a well established genetic calculation, it would be expected that 88 % of humans would fail to reproduce. The authors regard this as a long-standing unsolved paradox, and try to suggest an answer. But it may not be a paradox - it may simply be what happened in human populations most of the time and in most places through history (in equilibrium, on average) up to about 1800.  

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Even if this number is too big, even if it is much too big, the point is that in order to prevent the accumulation of damaging mutations generation upon generation, in order to prevent the population being overwhelmed and destroyed by genetic damage; a lot of humans would need to fail to reproduce...

Which, given that - in pre-contraception and -abortion eras - a lot of humans are born (i.e. fertility is high), then there must be *very" high child mortality rates.

To put this in terms of eugenics, a large majority of people would not be allowed to reproduce at all, or else a large majority of children would have to die (or be killed) merely to stop dysgenics from mutation accumulation - this would have to happen just for things to stay the same.

To actually improve the functional-adaptedness of the population - in other word to practice eu-genics (by differentially breeding from the better- adapted) would have to come on top of this.  

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To put it simplistically - to perform actual eu-genics as a matter of state policy would require something like the following: 

1. Slaughter c. 88% of children or sterilize c. 88% of adults, to stay the same - and then... 

2. Of the remaining c. 12%, breed only from the best adapted minority - to improve the population.  

Knowing this, are you still in favour of eugenics? 

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It has been pointed out that in its common usage the term 'dysgenics' lacks biological validity.

For example, the decline of average intelligence in a population is often described as a dysgenic change, on the basis that a decline in intelligence is (it can be argued) a bad thing on the whole for human society.

However, it could be argued that insofar as a decline in intelligence was due to a differential selection against higher intelligence people (for example, by a chosen reduction in fertility) and in favour of lower intelligence people (who perhaps cannot or will not use contraception) - then this is just 'natural selection as usual' - and indeed the fitness of the population is being enhanced under conditions where fertility rates are either very low, sometimes at sub-replacement/ long-term extinction levels.

Insofar as this is what is happening with the decline of intelligence then it is indeed just natural -selection-as-usual in that genetic mutations leading to adaptations are being handed-on from parents to their offspring.

Better adapted parents - i.e. those parents resistant to the fertility-suppressing effects of modernity - are producing a higher proportion of offspring (in the next generation) than are parents who are susceptible to fertility suppression. 

Fitter parents (fitter in terms of the actual environment) have fitter children.

*

But insofar as the decline in intelligence is due to an accumulation of deleterious mutations (and the vast majority of new mutations will be more-or-less deleterious), then this is real dysgenics: objectively measurable, and biologically distinct from natural-selection-as-usual.

This is because with mutation accumulation, the parent is not transmitting adaptations to the offspring, but newly-occurred genetic damage. The parent does not share the mutational damage which is suffered by the offspring - since that genetic damage has occurred during the process of reproduction.

Since the new genetic mutations have not been inherited from a parent, and parents are not handing-on adaptations - then mutation accumulation is not a consequence of natural selection.

*

So in principle mutation accumulation is a biologically-objective dysgenic process (while differential selection of heritable traits is not) - and mutation accumulation could be measured phenotypically in terms of damage to adaptations, or genetically in terms of mutational damage to those suites of genes which underlie phenotypic adaptations.

For example, objectively and biologically dysgenic change from mutation accumulation, would include new (not inherited) mutations which led to infertility, or blindness, or fatal genetic diseases of childhood - since these phenotypic changes are objective; or else (if known) detectable as the genetic changes which underlie adaptations such as sexual attraction mate selection, fertility, child care, vision, or the functionality of any major essential organ system such as blood, cardiovascular or respiratory.

8

With mutation accumulation children are less fit than parents.

Or, offspring are less fit than parents with reference to the parental environment.

(It is necessary to add this rider, because in modern conditions the less fit offspring have experienced a different, and more favourable, environment than their parents. So, the functional impairment of several generations of offspring has been concealed by a 'softer' and more supportive environment, as society became richer per capita, and mortality rates fell. )

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In conclusion, dysgenics can be used in a non-biological and subjective way - to refer to any disapproved-of genetic change in a population; or in a rigorous, objective and biologically-valid way - to describe a non-hereditary generational reduction in fitness in a population: the incremental loss of functional adaptations in a population.

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Reference: The essence of this idea came from, and should be attributed to, Michael A Woodley.

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The so-called Mouse Utopia experiment was conducted from 1968 by John B Calhoun

http://en.wikipedia.org/wiki/John_B._Calhoun

The idea was that four breeding pairs of mice were allowed to reproduce freely in a 'utopian' environment with ample food and water; no predators; no disease; comfortable temperature, conditions and space. What happened is described by the author:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1644264/pdf/procrsmed00338-0007.pdf


Phase A - 104 days - establishment of the mice in their new environment, then the first litters were born.

Phase B - up to day 315 - exponential population growth doubling every 55 days.

Phase C - from day 315-560 population growth abruptly slowed to a doubling time of 145 days.

Phase D - days 560-920; population stagnant with births just matching deaths. Emergence of many pathological behaviours.

Terminal Phase - population declining to zero. The last conception was about day 920, after which there were no more births, all females were menopausal, the colony aged and all of them died.

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The Mouse Utopia experiment is usually interpreted in terms of social stresses related to 'over-population' crowding - generating pathological behaviours and a loss of the will to live.

But Michael A Woodley suggests that what might be going on is mutation accumulation, and deleterious genes generating a wide range of maladaptive pathologies, incrementally accumulating with each generation; and rapidly overwhelming and destroying the population before any beneficial mutations could emerge to 'save; the colony from extinction. 

So the bizarre behaviours seen especially in Phase D - such as the male 'beautiful ones' who appeared to be healthy and spent all their time self grooming, but were actually inert, unresponsive, unintelligent, uninterested in reproduction - are not adaptations to crowding, but maladaptive outcomes of a population sinking under the weight of mutations.

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The reason why mouse utopia might produce so rapid and extreme a mutation accumulation is that wild mice naturally suffer very high mortality rates from predation.

Therefore, because wild mice are so short-lived, mice are not 'built to last' and have the reputation of being unusually-prone to produce new deleterious mutations (and are therefore extremely prone to cancer, and susceptible to carcinogens - which is why mice are used to test for carcinogens).

Thus mutation selection balance is in operation among wild mice, with very high mortality rates continually weeding-out the new mutations (especially among males) - with typically only a small and relatively mutation-free proportion of the (large numbers of) offspring surviving to reproduce; and a minority of the most active and healthy (mutation free) males siring the bulk of each generation.

However, in Mouse Utopia, there is no predation and all the other causes of mortality are reduced to a minimum - so the frequent mutations just accumulate, generation upon generation - randomly producing all sorts of pathological (maladaptive) behaviours.

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To test whether mutation accumulation is the real explanation for the demise of Mouse Utopia, the original experiment should be repeated but with genetic controls. Woodley is hoping to do this himself.

Also, a variant experiment could perhaps be conducted, which maintained utopian conditions but without allowing overcrowding (e.g. by continually splitting-up the growing community, and creating more and more small colonies - or (see comment below) by random culling).

In other words, the social conditions of Utopian mice would be held constant, while mortality rates would be kept low for multiple generations. 

My prediction would be that the Mouse Utopians would go through phases A, B, C, D and terminal to become extinct even without increased population density/ overcrowding, and due purely to cumulative genetic damage.

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I have come across a useful round-up the idea of mutation accumulation as the most likely significant mechanism for rapid decline in human intelligence over the past eight or so generations:

http://wasdarwinwrong.com/korthof97.htm

This author came across the idea in WD Hamilton's second volume of Narrow Roads of Gene Land - just as I did:

http://iqpersonalitygenius.blogspot.co.uk/2013/02/what-are-genetic-causes-of-dysgenic.html

and he fills in the background and more recent history of this idea.

My only major quibble with this article is that the first and most-important and earliest cause of mutation accumulation was the decline in childhood (i.e. pre-sexually-mature) mortality rates starting from the agricultural and industrial revolutions.

This means that mutation accumulation very probably began in Britain from 1750-1800 and was becoming measurably apparent by 1850. Apart from public health and hygiene (e.g. water supply) improvements, medical breakthroughs would only have begun to have an effect on natural selection from the early 20th century.


So mutation accumulation as a cause of dysgenesis is not an abstract and theoretical speculation about the future - something possible unless we do x, y, and z...

No! Whatever may happen from now onwards - mutation accumulation is something that has already happened, beginning several generations ago - and the product of dysgenic change is us, i.e. the modern population in developed nations: we are it.

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From Michael Lynch. Rate, molecular spectrum and consequences of human mutation. PNAS 2010; 107: 961-8. 

What is the likely magnitude of the per-generation loss in human fitness caused by recurrent introduction of deleterious mutations? From the present results, we infer that an average human gamete acquires approximately 38 de novo base-substitution mutations, approximately three small insertion/deletions in complex sequence, and approximately one splicing mutation. Transposable-element insertions, microsatellite instabilities, and segmental duplications and deletions of total or partial gene sequences will almost certainly sum to several additional events per gamete, so it is likely that an average newborn acquires a total of 50 to 100 new mutations at the diploid level, a small subset of which must be deleterious.

The net fitness consequences of human mutations remain unclear and will likely continue to be a major challenge, but some general arguments allow an order-of-magnitude assessment of the situation. Using rather different approaches, Yampolsky et al. and Eyre-Walker et al. have derived similar estimates of the distribution of fitness effects of new amino acid altering base-substitution mutations: approximately 11% cause fractional reductions in heterozygote fitness with s < 10⁻⁵, 12% with 10⁻⁵ < s < 10⁻⁴, 50% with 10⁻⁴ < s < 10⁻², and 27% with s > 10⁻², with an overall average selective disadvantage of approximately 0.04. Only approximately 1.5% of the human genome consists of coding DNA and approximately 25% of coding sites are silent, so we expect approximately 0.86 novel amino acid altering mutations per newborn. Approximately 5% of such mutations will lead to nonsense mutations, many of which will likely be in the category of s > 10⁻², but the remaining 95% will be missense in nature, with deleterious fitness effects averaging approximately 4% or less according to these results. Thus, with a complete relaxation of natural selection, the expected decline in fitness associated with mutations in coding DNA alone appears to be on the order of 1% to 3% per generation.

Less clear is the added contribution from other forms of mutations. The vast majority of point mutations reside outside of coding regions (on the order of 40 per gamete), and it is likely that most of these will have very minor fitness effects, with average s almost certainly << 10⁻². Nevertheless, Eöry et al. make a compelling case that approximately 4% of intergenic, 15% of UTR, and 22% of silent sites are under weak purifying selection in humans, which is consistent with the arguments presented above for base-composition selection. Most major deletions and splicing mutations are probably highly deleterious, as they will generally render their host genes nonfunctional. Most transposable-element insertions and gene duplications appear to be at least weakly deleterious; the average deleterious effects of such mutations are likely to be at least 1% per event, and as noted earlier, at least one such event is likely to arise per zygote per generation. Thus, although there is considerable uncertainty in the preceding numbers, it is difficult to escape the conclusion that the per-generation reduction in fitness due to recurrent mutation is at least 1% in humans and quite possibly as high as 5%.

Although such a mutational buildup would be unnoticeable on a generation timescale, over the course of a couple of centuries (approximately six generations), the consequences are likely to become serious, particularly if human activities cause an increase in the mutation rate itself (by increasing levels of environmental mutagens). A doubling in the mutation rate would imply a 2% to 10% decline in fitness per generation, and by extension, a 12% to 60% decline in 200 years... 

Unfortunately, it has become increasingly clear that most of the mutation load is associated with mutations with very small effects distributed at unpredictable locations over the entire genome, rendering the prospects for long-term management of the human gene pool by genetic counseling highly unlikely for all but perhaps a few hundred key loci underlying debilitating monogenic genetic disorders (such as those focused on in the present study)…

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The paper referenced here:
  
Yann Leseque et al. A Resolution of the Mutation Load Paradox in Humans. Genetics 2012; 191: 1321-1330.



could provide a way into the literature on accumulated mutation damage in other species.

There seem to be a number of variables to consider - how many new mutations per generation, what proportion of offspring survive, how fast the population is growing and probably others.

Although this literature says 88% mortality or 12% surviving,  this is only approximate - and there would have been considerable variation at different points in history.

It also seems a bit high for human reproductive capability - since hunter gatherer women seem seldom to have more than six children (due to late menarche, the children spaced-out by the contraceptive effect of lactation, prolonged lactation and then low fertility from age c 40) - which would not be enough.

So I guess the real number would be more like an average 1/4 or 1/3 of human offspring surviving for most of the time and in most places.

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What about about delayed reproduction in modern populations?

Delayed reproduction leads to more chance of mutations (eg from sperm) and problems with poorer quality control on release of older eggs (eg trisomy twenty one is probably the tip of an iceberg of similar problems).

But late reproduction also reduces the number of generations and the possibility of mutation accumulation from that cause - so that modern people only have two generations (e.g. average thirty plus years) - i.e. two new lots of mutations in sixty-something years - where in historical times there would have been three generations per 60-70 years - three lots of new mutations.

So slowing reproduction (by increasing the average age of reproduction) may perhaps reduce mutation accumulation temporarily; given that the effect of aging on mutations may be less per decade than the effect of an extra generation of new mutations.

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This was originally a comment at a new blog called Brain Size

http://brainsize.wordpress.com/2014/06/30/could-genetic-iq-really-have-declined-so-much-so-quickly/

Which is shaping-up to be a valuable contribution to intelligence research.

The author, Herr Professor Doktor Pumpkinperson, has the attributes of honesty, persistence (this especially), intelligence and a refreshing disinclination to take offense at the criticism of others!

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In the Mouse Utopia experiment, an optimal environment with ample food, space, temperature, no predation etc. was created for 8 pairs of healthy breeding mice - but eventually the entire colony died, every single mouse - because after about two and a half years there were no more conceptions. The colony became sterile.

http://iqpersonalitygenius.blogspot.co.uk/2014/07/the-demise-of-mouse-utopia.html

Before they died there were several phases

Phase A - 104 days - establishment of the mice in their new environment, then the first litters were born.

Phase B - up to day 315 - exponential population growth doubling every 55 days.

Phase C - from day 315-560 population growth abruptly slowed to a doubling time of 145 days.

Phase D - days 560-920; population stagnant with births just matching deaths. Emergence of many pathological behaviours.

Terminal Phase - population declining to zero. The last conception was about day 920, after which there were no more births, all females were menopausal, the colony aged and all of them died.

This is interpreted as a consequence of mutation accumulation leading to extinction from mutational meltdown:

http://charltonteaching.blogspot.co.uk/2014/09/the-danger-of-mutational-meltdown-in.html

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As far as I can gather, mice are fully ready to reproduce at about 4 months, so the average generation time is probably about 5 months which is about 150 days.

So, starting with 104 days as zero - when reproduction began; we can convert the above timings into mouse generations

Phase B exponential growth doubling every 55 days lasted 201 days, = 1.3 mouse generations.

Phase C exponential growth doubling every 145 days lasted a further 245 days = 1.6 mouse generations.

So population growth phase in utopian conditions lasted only 3 mouse generations. 

Phase D of population stagnation phase lasted a further 360 days = 2.4 mouse generations

Therefore, the last conception (and de facto inevitable extinction) was 816 days after breeding commenced = 5.4 mouse generations.

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Human generations are conventionally 25 years, although these have slowed to about 30 years in Western countries in the past several decades - but let us therefore give two values - one for 25 year, and the other for 30 year human generations.

If we start at 1850 as the date when the Industrial Revolution seems to have become certainly established and child mortality rates began to drop rapidly, and start counting generations from that point, and if humans were made like mice (which they are not!)...

We would then predict that human population growth phase (B & C) would last three generations up to 1925-1940 

And the stagnation phase (D) for another 2.4 generations - with 5.4 human generations taking us up to 1985-2012.

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Well, clearly English people did not stop conceiving three years ago, because babies are still being born to native English - albeit not at a high rate!

I have previously guesstimated that the English situation  was that the slower growth phase c began in about 1920 (not about 1880) and the plateau phase began in about 1970) not 1930-ish

http://iqpersonalitygenius.blogspot.co.uk/2014/07/modern-england-as-mouse-utopia.html

So maybe England is lagged about 40 years, because 1. we are not mice, and 2. our mouse utopia emerged only incrementally and was probably not complete until about 1950.

So we do not need to worry about mutational meltdown and de facto extinction (i.e. the final English child of English parents and ancestry being conceived) for, oh, another thirty or forty years...

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Nonetheless, I draw the following lessons.

1. Assuming the decline and extinction of mouse utopia was due to mutation accumulation leading to mutational meltdown - then it happened very quickly indeed: only mouse 5.4 generations to the final conception, with half of that being stagnation.

2. The decline in rate of population increase after only 1.3m mouse generations suggests that the effect of relaxed natural selection and mutation accumulation leads to genetic damage immediately, in the very first generation.

3. Although humans (maturing over 14 years and with a natural life expectancy about 70 years) are built to last longer than mice (maturing over 4 months and living about 2 years) - this may mean that humans are more vulnerable to mutation accumulation - because we have a more prolonged and multi-phasic development and depend on extremely-complex brains which use many genes make and to function, and constitution large mutational targets.

4. In mouse utopia, the mouse environment, shelter, food, hygiene etc were all managed by humans - and did not depend on the mice doing anything much for themselves except east, sleep, fight, groom and reproduce (until they altogether lost interest in sex)- but humans depend on other humans for survival.

When the human population is damaged from mutation accumulation, this will destroy the 'utopian' environment. If this destruction is severe enough and comes early enough- then mutational meltdown will be avoided.

But if there is a generational lag - and utopia is maintained sufficiently that further mutational damage to younger generations continues to accumulate - then this will hasten the meltdown and extinction; because by the time utopia comes to an end, the younger generations will be unfit to survive the harsher conditions.


Have a nice day!

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The idea of r/K selection theory applied to humans is that a population could be r-selected for fast Life History - such as rapid sexual maturation and high fertility, with relatively low levels of parental investment into each offspring;

or else K-selected, for a slower and more long-termist Life History - fewer offspring with more gradual and delayed development, and investing more resources per child (with the aim of generating more cognitively specialized adults).

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(In a nutshell, and approximately - r selection is for quantity, K selection is for quality. In some environments only 'high quality' offspring - making which requires longer development and more resources - are able to compete successfully with other members by aiming for narrow niches requiring particular qualities.)

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But r and K are not opposites. Nor are they reciprocal: to reduce one does NOT mean to increase the other. 

Because 'selected-for' means 'specialized-for'.

And specialization implies adaptation.

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Therefore to be r-selected is to be specialized-for r - this means that an r-selected population has evolved a suite of adaptations which together enable it to become better at rapid and fecund reproduction.

And to be K-selected is to be specialized in producing offspring who have a better chance of themselves reproducing in a context of more long-termist Life History.

And to lose long-termist adaptations of K-selection is NOT thereby to gain short-termist adaptations; and to lose short-termist adaptations is NOT thereby to gain long termist adaptations.

So, in the modern world, the selective regime in the West has resulted in sub-replacement fertility for K-selected populations, and this will indeed destroy-K selected adaptations; but the resulting population will NOT thereby have r-selected adaptations by default - the population will just lose adaptiveness!

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(Loss of adaptiveness is - more or less - disease. Mutation accumulation is disease. On average, disease does not benefit adaptation in any way.)

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And a selective regime (such as the modern world) which reduces child mortality from approximately 60 percent to about 1 percent, allows mutation accumulation in r-selected populations.

Mutation accumulation will NOT increase r-selected abilities, it will NOT improve short-termist adaptations - but the opposite: these r-selected populations will lose their Fast Life History adaptations, as these specialized attributes enabling a fast Life History will be damaged by accumulating deleterious mutations.

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So the modern world is NOT becoming more r-selected - it is become less K-selected AND less r-selected: the modern world is becoming less adapted all round. 

This is concealed (temporarily) by the expansion in numbers of the previously r-selected populations- which is enabled by the massive reduction in child mortality rates and an increase in longevity - and an illusion of r-adaptedness - but in fact these populations are LESS r-adapted now than they were before their populations began to expand.

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If r-selection is summarized as specializing for quantity and K-selection as specializing for quality - then both high quantity and high quality are adaptive products of evolution. And, destroying quantity does not improve quality - also destroying quality does not improve quantity.

So modernity does NOT increase r at the expense of K - instead, modernity destroys BOTH r and K adaptations by means of mutation accumulation.

What results is that humans as a whole have lost adaptations, both short-term adaptations and long-term adaptations: the human genome has been damaged.

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Note: The above idea comes from Michael A Woodley - to whom credit should be attributed; but any errors or inaccuracies in expression are my responsibility.
http://psycnet.apa.org/?&fa=main.doiLanding&doi=10.1037/a0024348
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I have been thinking about the expected effect of mutation accumulation - and I think there would be de-differentiation/ loss of specialized adaptations.

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I previously estimated that something like 2/3 to 3/4 of offspring failed to survive in historical times - and that this was the principal mechanism for elimination of deleterious mutations.

http://iqpersonalitygenius.blogspot.co.uk/2014/06/what-proportion-of-offspring-survived.html 

Modern child mortality rates are, by contrast, so low that it is inevitable that mutations will accumulate - and reducing intelligence is an inevitable consequence (since 'g' is a proxy measure of fitness).

Evidence for this comes from various sources including A Farewell to Alms: a brief economic history of the world, by Gregory Clark. Princeton University Press, 2007.

Also theoretical considerations:

http://iqpersonalitygenius.blogspot.co.uk/2014/05/mutation-accumulation-as-major-cause-of.html


And, further evidence on this matter is available from a pair of review/ meta-analysis papers:

A Volk and J Atkinson. Is child death the crucible of human evolution. Journal of Social, Evolutionary and Cultural Psychology. 2008; 2: 247-260.

A Volk, J Atkinson. Infant and child death in the human environment of evolutionary adaptation. Evolution and Human Behaviour. 2013; 34: 182-192.

In the 2013 paper, a review of hunter gatherer mortality found an average 48.8% child mortality rate - noting that child mortality rates are an underestimate, as not all deaths are recorded.

Historical data showed an average of 46.2% with a minimum of 35%, until modern times in developed countries, when it drops to 1% .

(However, among individuals, some will have a probability of lower, and others of higher mortality rates among their offspring, according to their health, status, child rearing abilities etc.)

http://iqpersonalitygenius.blogspot.co.uk/2012/08/why-are-women-so-intelligent.html 

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So about a half of children are known to have died before adult maturity in most times and most places, and the real percentage must have been higher.

In the 2008 paper, the authors note that most women who reach adulthood will have children, but about 5% may be infertile; by contrast about 10% of men fail to find a mate and about 5% are infertile. To this can be added the fertility-reducing effect of later marriage among low status men - often to older women with less reproductive potential.

This fits the idea that selection against deleterious mutations is stronger among men than women - with the variance of reproductive success larger among men; a smallish proportion of the fittest men differentially producing most of the viable offspring selection.

This also fits the anatomical picture of sexual dimorphism, with men as considerably more massive and strong than women, as consistent with some significant degree of de facto polygyny.

http://charltonteaching.blogspot.co.uk/2013/09/sexual-dimorphism-between-men-and-women.html

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So, among men at least 65% or two thirds will fail to reproduce according to direct measures from anthropological and historical data. 

Rates of failure to reproduce will differ between the sexes, with mortality differentially concentrated among men (and indeed male fetuses, babies and children - who suffer greater mortality than females - http://www.huli.group.shef.ac.uk/lummaaproceeding2001.pdf)

Given that 45-50 % directly-measured child mortality rates represents a minimum level; this evidence is reasonably consistent with my previous estimate; and emphasizes the massive change in selection pressure, and presumably mutation elimination, represented by a fifty-fold decline in child mortality rates from historical to modern times.

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Note: I should add that it is the number of surviving (and reproductively viable) children which is the key factor; not the proportion of children that survive. i.e. Reproductive success is about both fertility and mortality.

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In sum: Although both intelligence and personality differences (within a population) are highly heritable - general intelligence is a highly sensitive fitness marker (perhaps the most sensitive); therefore absolute (not differential) intelligence declines with dysgenic change.

In other words average intelligence tracks population average population fitness.

But, since it is highly heritable but not sensitive to fitness, personality should be much more robust to population fitness change.

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The work of Geoffrey Miller made clear that general intelligence is a sensitive fitness marker - in other words, high intelligence is a marker (or honest advertisement) of low mutational load.

(Because the brain is a large mutational target, therefore any deleterious mutation has a high probability of affecting brain function - and intelligence is the main summary measure of overall brain function.)

So as the mutational load of a population declines, we would also expect to observe a decline in intelligence - and this is indeed what we find. So average population intelligence (expressed on an absolute scale and measured - for example - by simple reaction times) has been declining for the same period as mutational accumulation has become significant - i.e. since the industrial revolution began sharply to reduce child mortality rates, and the differential mortality rates between the more-intelligent (lower mutational load) and less-intelligent (higher mutational load) went into reverse (with low intelligence becoming associated with higher reproductive success to relatively sustained fertility rates among the less intelligent, ion a context of greatly reduced/ nearly abolished mortality rates).

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BUT, although personality differences is approximately as heritable as intelligence, personality is not a sensitive marker of mutational load - although eventually personality would inevitably be affected by the cumulative dysfunctionalities of increasing mutation load.

Thus, personality is relatively buffered against dysgenics.

Therefore, when deleterious genetic mutations are accumulating in a population, we would not expect national personality to change as rapidly as national intelligence will change.

And indeed that seems to be what we observe! English national characteristics seem to have remained similar for several generations - indeed until about the middle of the twentieth century; despite the reduction in English intelligence and the collapse and near-disappearance of English genius.

But nowadays, at last - after several generations of buffering, we are seeing the consequences of mutation accumulation on personality, and on national character; with the English population - on average and en masse - showing many signs of change, and indeed decline into dysfunctionality and overt pathology.

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Note: The meaning of 'mouse utopia' can be seen in various posts on my Intelligence, Personality &amp; Genius blog:
http://iqpersonalitygenius.blogspot.co.uk/search?q=mouse+utopia
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The thesis is that we are already living in mouse Utopia, and that this will become more and more apparent until its reality will become... well, I was going to say 'undeniable' but that is silly: people can and do deny the most obvious things, and the process of population wide and cumulative mutational damage of the genome is certainly not obvious; but rather, at present, invisible.

So Mouse Utopia will never be undeniable, and indeed it is likely that the vast majority of mankind will never know what has hit them, and continues to hit them; nor will it ever be easy to disentangle the effects of genetic damage from other causes of maladaptive behaviour and disease. But at any rate, let's just say that the hypothesis of mutational accumulation in the human species will presumably gather more and more consistent evidence as time goes by.


What will life be like in Mouse Utopia? In The Narrow Roads of Gene Land Volume 2, WD Hamilton partially described that world in a chapter entitled The Hospitals are coming, and that is perhaps a good starting point - the idea that everyone will be damaged and most will be sick, in one way or another; so that life will resemble a hospital in which (some of) the less-sick (or the damaged but not-yet sick) tend the more-sick, as best they may - in intervals between doing whatever it takes to stay alive.

But this is not by any means an unusual or unprecedented situation for humans through much of the history of the species. For much of the time, Malthusian mechanisms have been in force, and populations have been limited by various combinations of starvation and infectious disease. Infections - in particular - have sometimes been endemic at a high prevalence, so that the majority or even all of the population might be suffering from, be affected by, some chronic parasitic disease - but at a relatively low degree of severity.

And with respect to the Mouse Utopia society being a Hospital, it is important to recognize that much of the pathology will be psychiatric rather than physical - this can be seen from the fact that the problems of the original Mouse Utopia were most behavioural rather than physical; and it follows from the fact that the highly complex human brain is exceptionally sensitive to random mutational damage.


Intelligence is probably damaged by mutation accumulation in an incremental and quantitative fashion - the more mutations, the more the lowering of intelligence. Therefore, decline of intelligence as mutations accumulate is likely to be relative smooth (rather than step-like).

But intelligence is 'general' intelligence, and is unusual in being a general attribute of cognitive function - it roughly corresponds to speed of processing, or coordinated functional efficiency. By contrast, most psychological functions are specific; and genetic damage is likely to be more qualitative and either step-like, or all-or-nothing.


What I think would happen, is that accumulating mutation damage would most likely show-up as varieties of specific brain functional damage leading to specific behavioural impairments of a social and sexual type - in a general context of continuing declining intelligence. (See reference below)

The kind of damage I am talking about represents a decline in functional adaptation of the human organism to its environment (its sexual, social and surrounding environment) - that is, a loss of effective functionality. This represents a decline in fitness, but not just relative fitness (because it is happening throughout the population) - it is a decline in group fitness - ultimately in species fitness.

If fitness is measured in terms of the capacity to raise sufficient viable offspring in a given environment; then the sexual and social changes induced by mutation accumulation will be such as to reduce the probability of doing this: partly by damage causing reduced brain processing speed and efficiency (detectable as reduced intelligence) and partly by damage causing specific functional impairments (detectable as sexual and social pathologies).


So, Mouse Utopia will be not so much be a hospital of sick people with the less sick tending the more sick; but more like the less crazy looking after the more crazy: a case of the lunatics have taken over the asylum because there is nobody left but the lunatics - so everyone in Mouse Utopia is mad, more-or-less; but with the sanest and most sensible people in charge.

At least, that would be optimal.

If the world is a psychiatric hospital where everyone is socio-sexually dysfunctional to some extent, then the people running the hospital ought to be the most coherent of the patients. Indeed, sanity is probably more of a priority than high intelligence - since a moderately intelligent coherent person (at least arguably) makes a better leader than a more highly intelligent crazy.

However, for the past fifty years and increasingly, we have been getting a taste of something different; and most nations and large organizations are now being run by - not the least impaired people - but energetic incoherent semi-lunatics; because in a mass media democracy, that is what the more-seriously-crazed majority seem to want.

Democracy as a system for choosing government has never made much sense; mass democracy in a mass media addicted world makes even less sense; democracy in a lunatic asylum is... crazy.