Tuesday, 17 June 2014

So, you think you are in favour of eugenics? Do you know the implications?

*

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.


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



    *

    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.  

    *

    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.  

    *

    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? 

    *

    14 comments:

    Valkea said...

    It worked very well for the Jews and we can learn the community oriented methods from them (Cochran, Hardy and Harpending, Natural History of Ashkenazi Intelligence, 2005):

    http://preview.tinyurl.com/q9koc2l

    Bruce Charlton said...

    @V - Well, it depends what you mean by 'worked very well' - something along the lines 'of every child born with an IQ less than 120 died' ; or any adults who could not perform high level calculations and make a living as merchants or money-lenders starved to death.

    But this wasn't by state policy or eugenic plan - it just happened, and likely wasn't much different in proportionate terms for Jews than anybody else (once the population had stabilized), except that it was (probably) mostly general intelligence that determined which small proportion of Jews survived, rather than other traits being selected-for at other times and places.

    Valkea said...

    According to the histories I have read the less intelligent Jews assimilated to the surrounding populations, or stayed in the Jewish communities and had fewer children than the richer families, who had the wealth to support larger families, and who had more surviving children through better hygiene and nutrition. If all the children born with IQ of less than 120 would have died, there would not have been the need for the famous Jewish charity, which helped many poorer and less intelligent Jews.

    Bruce Charlton said...

    @V I think that if the data was available it would be found that there was near 100% mortality rates at charitable relief institutions. This was the case for several foundling hospitals, for example. For much of history, charity was perhaps a duty, but ineffective in the long run. It could not be otherwise.

    Paul Warkin said...

    What's the alternative--a growing population whose fitness declines each generation until... some catastrophe? It seems there is no "nice" option.

    Bruce Charlton said...

    " It seems there is no "nice" option."

    That's how it seems to me. I regard it as something we should 1. be honest about and 2. cope-with and make-the-best-of, as far as we can - guided by Christian ethics.

    Haile Selassie said...

    If you believe in this huge disgenic tendency and that there is no nice option, I don't see how you could continue to believe in Christianity. God obviously wasn't thinking long-enough term. Either that or, I suppose it's a sign of Christ's imminent return.

    Bruce Charlton said...

    @HS - The point is that this is how things were everywhere pretty much all of the time until about 200 years ago, with the industrial revolution - it is simply a case of (massive, terrible) readjustment then 'normal service will be resumed' - and the most recent era will seem like an anomalous blip.

    Although who knows really - the accumulation of mutations would reduce adaptation, so the human population may drop lower than it was before the industrial revolution, or become extinct - there are no guarantees in biology.

    But ultimately, you are right to emphasize that we are in the latter days or end times, and maybe that will come first? Nobody knows .

    contemplationist said...

    What about 'free market eugenics' driven by cheap genomics, embryo testing and selection for traits? It will happen because parents want 'better' children.

    Valkea said...

    I would like to first see the data about death rates of poorer / less intelligent Jews in historical times. Near 100% seems like an exaggeration in the light of what I have read.

    Note also that eugenics is part of Christianity. Joseph's story is the first eugenic story, where Joseph's intelligence overcomes all obstacles; birthrigt of his older brothers, enmity of his brothers, slavery, imprisonment etc., and Joseph intelligence, knowledge and abilities raises him to be the second most important ruler in Egypt. Jewish eugenic practices are based on this story and it is a part of Christianity too. Jakob practices eugenics with his goats and lambs in Genesis 30:25-43. The Jewish understanding of the importance of eugenics in humans arises from these observations of and practises with animals.

    Bruce Charlton said...

    @c and V - Given the overwhelming effect of mutation accumulation, all this is spitting into a hurricane.

    vultureofcritique said...

    Dear Sir,
    if you would permit me a self-link, I will refer to some of my writings on this topic:

    http://vultureofcritique.wordpress.com/2014/06/18/how-many-people-would-have-to-die-for-a-eugenic-program/

    Sonny said...

    The reason that "eugenics" never gets anywhere and never will under that terminology is that it's constantly associated with killing and forcible sterilizations. Those means are evil and orthogonal to good breeding. Breeders don't produce a better breed of horse by going around killing or sterilizing horses or mules. They don't concern themselves with that at all. They select horses that they consider as having desirable traits, and breed those at artificially enhanced rates, and select further from that lineage in each generation.

    So it would only take one little country or subculture involved in order to have good breeding. The idea that that's impossible or it would require killing or force is one of many bad ideas that are produced by the assumption that world communism has already been achieved and can never be undone. (Another idea produced by that assumption is that sustainability is impossible without totalitarianism or a worldwide collapse and return to nature, because there's world population growth and world resource use growth for world per capita consumption growth, and everything must be shared worldwide, and the planet is finite.)

    So what appears to be going on here is because the word "eugenics" stands for a failed movement that tried to forcibly prevent in the most direct way what it considered bad breeding or even bad living, and that was associated with totalitarian states and visions of totalitarian states, then it is concluded that a state cannot be involved in a country or a culture having "eugenics" without terrible evil resulting. Suppose that "environmentalism" becomes associated with states killing and forcibly sterilizing in order to reduce the surplus population, thus conserving natural resources. Then obviously a state could never morally be allowed to promote "environmentalism." Actually some conservatives already write as if "Malthusianism" is just such an evil to be resisted and purged from government.

    Bruce Charlton said...

    @Sonny - I think historically that eugenics was mostly concerned with eliminating bad genes, rather than enhancing good ones - but I am very familiar with the idea of using selective breeding to improve the elite since it was advocated over many years by George Bernard Shaw - on whose writings I was something of an expert.

    Shaw often wrote about the possible benefits of breeding from the 'best' men and women - and how this process should be detached from marriage and family life (the breeding being purely sexual, and children being raised by clean, efficient state orphanages) .

    (Certainly, the elites have proved extremely reluctant to reproduce under all modern conditions - the only exceptions being among the devoutly and traditionally religious. But atheists seem to require some kind of strong compulsion to reproduce, and elites have so far refused to inflict this duty upon themselves.)

    At times, Shaw hoped (sometimes a desperate hope, as he got older) that this might lead to a new race of Supermen artist-philosopher-politicians - natural leaders to lead mankind out of the morass.

    A modern spin on this is transhumanism - indeed thoughtful atheist idealists sooner or later realize that nothing can be hoped for from humans as they are - and therefore place their hope in humans as they might become - hence this strand of eugenics, and the hopes for genetic engineering etc.

    There is, of course, a paradox in trying improve the human condition by developing something which is not human (and is supposedly 'uber' human - a super-man - a creature modified from humans but better than humans).

    Since the human species is to be changed, this view is therefore linked with a concern for more than humans - and both Shaw and same transhumanists are vegan/ animals rights people.

    On the other side of this we could range CS Lewis in That Hideous Strength - who identifies this eugenic aspiration as a very advanced form of anti-human evil. This is the correct view, in my opinion - but it is only open to those who accept the reality of divine revelation.

    I would say that idealistic atheism more-or-less channels thoughtful people into some version of the eugenic search/ hope for Superman.