Darwin the Newtonian. Part V. A spectrum, not a dogma

Our previous installments on genetic drift (a form of chance) vs natural selection (a deterministic force-like phenomenon) and the degree to which evolution is due to each (part 1 here) lead to a few questions that we thought we'd address to end this series.

First, there is no sense in which we are suggesting that complex traits arise out of nowhere, by 'chance' alone.  There is no sense in which we are suggesting that screening for viability or utility does not occur as a regular part of evolution.  But we are asking what the nature of that screening is, and what a basically deterministic, Newtonian view of natural selection, that is we believe widely if often tacitly held, implies and how accurate it may be.

It's also important here to point out something that is obvious.  The dynamics of evolution from both trait and genome level comprise a spectrum of processes, not a single one that should be taken as dogma.  A spectrum means that there is a range of relative roles of what can be viewed as determinism and chance that the two are not as distinct as may seem, and that even identifying, much less proving what is going on in a given situation is often dicey.  Some instances of strong selection, like some of chance seem reasonably clear and those concepts are apt.  But much, perhaps most, of evolution is a more subtle mix of phenomena and that is what we are concerned with.

Secondly, we have discussed our view of natural selection before, in various ways.  In particular, we cite our series on what we called the 'mythology' of selection, a term we used to be provocative in the sense of hopefully stimulating readers to think about what many seem to take for granted.  Yes, we're repeating ourselves some, but think the issues are important and our ideas haven't been refuted in any serious way so we think they're worth repeating.

A friend and former collaborator took exception to our assumption that people still believe that what we see today is what was the case in the past.  He felt we were setting up a straw man. The answer is somewhat subjective, but we believe that if you read many, many descriptions of current function and their evolution, you'll see that they are often if not usually just equated de facto with being 'adaptations', and that means that doing what they do now came about because it was favored by the force of selection in the past.  We think it's not a straw man at all, but a description of what is being said by many people much of the time: very superficial, dogmatic assumptions both of determinative selection and that we can infer the functional reason.

Of course everyone acknowledges that earlier states had their own functions and today's came from earlier, and that functions change (bat wings used to be forelegs, e.g.), but the idea is that bat flight is here because the way bats fly was selected for.  One common metaphor going back to an article by Lewontin and Gould is that evolution works via 'spandrels', traits evolved for one purpose or incidentally part of some adaptation, that are then usable by evolution to serve some new function. Yes, evolution works through changing traits, but how often are they 'steps' in this sense or is the process more like a rather erratic escalator, if we need a metaphor?

There are ways for adaptive traits to arise that have nothing to do with Darwinian competition for limited resources, and are perfectly compatible with a materialist view.  Organismal selection occurs when organisms who 'like' a particular part of their environment, tend to hang out there.  They'll meet and mate with others who are there as well.  If the choice has to do with their traits--ability to function at high altitude, or whatever--then over time this trait will become more common in this niche compared to their peers elsewhere, and eventually mating barriers may arise, and a new species with what appears to be a selected adaptation. But no differential reproduction is required--no natural selection.  It's natural assortment instead.

All aspects of our structure and function depend on interaction among molecules.  If two molecules must interact for some function to occur, then mutant versions may not serve that purpose and the organism may perish. This would seem most important during embryonic development.  An individual with incompatible molecular interactions (due to genetic mutation) would simply not survive.  This leaves the population with those whose molecules do interact, but there is no competition involved--no natural selection.  It's natural screening instead.

Natural selection of the good ol' Darwinian kind can occur, leading to complex adaptations in just the way Darwin said 150+ years ago.  But if the trait is the result of very many genes, the individual variants that contribute may be invisible to selection, and hence come and go essentially by chance. This is what we have called phenogenetic drift.  Do you doubt that?  If so, then why is it that most complex traits that are mapped can take on similar values in individuals with very different genotypes?  This is, if anything, the main bottom line finding of countless very large and extensive mapping studies, in humans and even bacteria.  This is basically what Andreas Wagner's work, that we referred to earlier in the series, is about.   It rather obviously implies that which of equivalent variants proliferates is the result of chance.  There's nothing non-Darwinian about this.  It's just what you'd expect instead.

We'd expect this because the many factors with which any species must deal will challenge each of its biological systems. That means many screening factors (better we think than calling them selection 'pressures' as would usually be done).  Most of these are affected by multiple genes.  Genes vary within a population.  If any given factor's effects were too strong, it would threaten the species' existence.  At least, most must be relatively weak at any given time, even if persisting over very long time periods.  Multiple traits, multiple contributing genes in this situation means that relative to any one trait or gene, the screening must be rather weak.  That in turn means that chance affects which variant proliferates.  There's nothing non-Darwinian about this.  It's essentially why he stressed the glacial slowness of evolution.

There is, however, the obvious fact that known functional parts of DNA are far less variable than regions with no known function.  This can be, and usually is assumed to be, the expected evidence of Darwinian natural selection.  But factors like organismal dispersion or functional (embryonic) adequacy can account for at least some of this.  Longer-standing genes and genetic systems would be expected to be more entrenched because they can acquire fewer differences before they won't work with other elements in the organism.  This is at least compatible with the view we've expressed, and there could be some ways of testing the explanation.

This view means we need not worry about whether a variant is 'truly' neutral in the face of environmental screening.  We could even agree that there's no testable sense in which a variant evolves by 'pure' chance. Even very tiny differences in real function can evolve in a way that is statistically 'neutral'.  Again, this can be the case even if the trait to which such variants contribute is subject to clear natural or other forms of selection.

This view is also wholly compatible with the findings of GWAS, the evidence that every trait is affected by genetic variation to some extent, the fact that organisms are adapted to their environment in many ways and the fact that prediction based on genotyping is often a problematic false promise.  And because this is a spectrum, randomly generated by mutation, some variants and or traits they affect will be very harmful or helpful--and will look like strong, force-like natural selection.  These variants and traits led to Mendel, and led to the default if often tacit assumption that natural selection is the force that explains everything in life.

Further, it is important for all the same sorts of reasons that the shape of the spectrum--the relative amount of a given level of complexity--is not based on any distribution we know of and hence is not predictable, generally because it is the result of a long history of random and local context and contingencies, of various unknown strength and frequency (about the past, we can estimate a distribution but that doesn't mean we understand any real underlying probabilistic process that caused what we see).  This is interesting, because many aspects of genetic variation (and of the tree of life) can be fitted to a reasonable extent to various probability distributions (see Gene Koonin's paper or his book The Logic of Chance).  But these really aren't causal parametric 'laws' in the usual sense, but descriptions after the fact without rigorous causal characteristics.  Generally, prediction of the future will be weak and problematic.

In the view of life we've presented, evolution will have characteristics that are weak or unpredictable directional tendencies, and the same for genetic specificities (and hence predictive power). It is the trait that is in a sense predictable, not the effects of individual genes.

We think this view of evolution is compatible with the observed facts but not with many of the simplified ideas that are driving life sciences at present.

Our viewpoint is that the swarm of factors environmental and genomic means that chance is a major component even of functional adaptations, in the biodesic paths of life.

Darwin the Newtonian. Part II. Is life really 'Newtonian'?

In yesterday's post I suggested that Darwin had a Newtonian view of the world, that is, he repeatedly and clearly described the organisms and diversity of life as the product of evolution, due to natural selection viewed as a force, which in an implicit way he likened to gravity.  At the same time, he knew that there was widespread evidence of various kinds for long-term evolutionary stasis, which a prominent geologist has recently called  "Darwin's null hypothesis of evolution," the idea that evolution does not occur if the environment stays the same.

That suggests that a changing environment leads to a changing mix of organisms that live in the environment, including of their genotypes.  It makes evolutionary sense, of course, because environments screen organisms for 'fitness'.  However, its negative--no change in the environment implies no evolution-- doesn't make sense and badly misrepresents what is widely assumed that we know about evolution. Even if we define evolution, as often done in textbooks, as 'change in gene frequencies' such change clearly occurs even in stable environments.  Mutations always arise, and selectively neutral variants, that is, that don't affect the fitness of their bearers, change in frequency by chance alone, not by natural selection, which means that at the genomic level evolution still occurs. It's curious that not only can organisms stay very similar in what seem like static environments, but also can be similar even in changing environments.

The idea of dual environmental-genetic stasis is an inference made from species that seem to stay similar for long time periods in environments that also appear similar--but how similar are they really?

Indeed, there are several problems with the widely if often implicitly assumed 'null hypothesis':

  1.  It is a very narrow assumption of the meaning of 'evolution', implicitly implying that it refers only to functionally important traits or their underlying genotypes. As we will see, there are ways for genetic change (and even trait change) to occur even in static environments, so that an unchanging environment doesn't imply no biological change.
  2.  It implies that 'the environment' actually stays the same, although 'environment' is hard to define.
  3.  It implies a tight essentially one-to-one fit between genotype and adaptive traits, so that in unchanging environments there will not be any functional genomic change.

All of these assumptions are wrong.  In essence, there cannot be 'the', or even 'a' null hypothesis for evolution.   Sexual reproduction, horizontal transfer, and recombination occur even without new sequence mutation.  To ignore that along with assuming a stationary environment, and adopt a null hypothesis that had anything like mathematical or Aristotelian rigor would be to reduce evolution's basis to something like this not-very-profound tautology:  Everything stays the same, if everything stays the same.

So let's look at this a little more closely
From the fossil record, we infer that some species stay the 'same' for eons, sometimes millions of years.  Then they change.  Gould and Eldridge called this 'punctuated equilibrium' and it was taken as a kind of up-dated version of Darwinism--mistakenly, because Darwin recognized it very clearly at least by the 6th edition of his Origin.  And while some aspects of animals and plants can hardly change in appearance for long time periods, close inspection shows that only some aspects of what can be preserved in fossils stays similar; other aspects typically change.  Also, speciation events occur and some descendants of an early form do change in form, even if the older species seems not to change. So we should be very careful even to suggest that environments or species really are not changing.

But mutations certainly occur and that means that even for a set of fossils that look the same, the genomes of the individuals would have varied, at least in non-functional sequence elements.  That itself is 'evolution', and it is misleading to restrict the term only to visible functional change.  But genetic drift is just the tip of the molecular evolution iceberg.  It is now very clear that there are many ways for an organism to produce what appears to be the same trait--and this is true both at the molecular and morphological levels.  That is, even a trait that 'looks' the same can be produced by different genotypes.  I wrote about this long ago in a rather simple vein, calling it phenogenetic drift, and Andreas Wagner in particular has written extensively about it, with sophisticated technical detail, in his book The Origin of Evolutionary Innovation, and this paper.  (The images are of my general paper and Wagner's book given just to break up the monotony of long text! ; he has written a more popular-level book as well called Arrival of the Fittest, which is a very good introduction to these ideas).

Recent exploration, with great detail

A modest statement of principl

Wagner explores this in many ways and among his views is that the ability of organisms to evolve innovative traits is based on the huge number of overlapping, essentially similar ways it can carry out its various functions, which allows mutations to add new function without jeopardizing the current one. Redundancy is protective against environmental changes as well as enabling new traits to arise.

This is in a sense no news at all. It was implicit in the very foundational concept of 'polygenic' control-- the determination of a trait by independent, or semi-independent of many different genes.  The way complex traits are thus constructed was clear to various biologists more than a century ago, even if the specific genes could not be identified (and the nature of a 'gene' was unknown).  A fundamental implication of the idea for our current purposes is that each individual with a given trait value (say, two people with the same height or blood pressure) can have its own underlying multi-locus genotype, which can vary among them.  Genotypes may predict phenotypes, but a phenotype does not accurately predict the underlying genotype (a deep lesson that many who promote simplistic models of causation in biomedical contexts should have learned in school).

And of course that does not even consider environmental effects, even though we know very well that for most characters of interest, normal or pathological, 'genetic' factors account only for a modest fraction of their variation. And, of course, if it's hard to identify contributing genetic variants, it's at least as difficult to identify the complex environmental contributors who make inference of phenotype from genotype so problematic. That is, neither does genotype reliably predict phenotype, nor does phenotype reliably predict genotype and the idea that they do so with 'precision' (to use todays' fashionable branding phrase) is very misleading.

In turn, these considerations imply that even if we accepted the idea of natural selection as a Newtonian deterministic force, it works at the level of the achieved trait, and can ignore (actually, is blinded to) the underlying causal genetic mechanism.  There can be extensive variation within populations in the latter, and change over time.  Just because two individuals now or in the past have a similar trait does not imply they have the same underlying genotype and hence does not imply there's been no 'evolution' even in that stable trait!

In this sense, evolution could be Newtonian, driven by force-like selection, and still not be genetically static.  But there's more.  How can there actually be stasis in a local environment?  If organisms adapt to conditions, then that in itself changes those conditions.  Even within a species, as more and more of its members take on some adaptive response to the environment, they change their own relative fitness by changing the mix of genotypes in their population, and that in turn will affect their predators and prey, their mate selection, and the various ways that the mix of resources are used in the local ecology.  If, say, the members of a species become bigger, or faster, or better at smelling prey, then the distribution of energy and species size must also change.  That is, the 'environment' cannot really remain the same.  That ecosystems are fundamentally dynamic has long been a core aspect of population ecology.

In a nutshell, it must be true that if genotypes change, that changes the local environment because my genotype is part of everybody else's 'environment'. In that sense, only if no mutations are possible can there be no 'evolution'. Even if one wants to argue that all mutations that arise are purged in order to keep the species the 'same', there will still be a dynamic mix of mutational variants over time and place.

One could even assert that an essence of Darwinism, literally interpreted, is that environments cannot be the same because the adaptation of one species affects others, even were new mutations not arising, because it affects the fitness of others. That is what his idea of the relentless struggle for existence among species meant, so stasis did cause him a bit of a problem, which he recognized in the later edition of the Origin.

I think that in essence Darwin viewed natural selection as being basically a deterministic force, like gravity, corresponding to Newton's second law of motion. And the idea of stasis corresponds to Newton's first law, of inertia. Today even many knowledgeable biologists seem to think in that way (for example, invoking drift only as a minor source of 'noise' in otherwise force-like adaptive evolution). Selective explanations are offered routinely as true, and the word 'force' routinely is used to explain how traits got here.
But there are deep problems even if we accept this view as correct.  Among other things, even if natural selection is really force-like, or if genetic drift exists as a moderating factor, then these factors should have some properties that we could test, at least in principle.  But as we'll see next time, it's not at all clear that that is the case.

Would you still go into the lab if you knew life on Earth was going to end tomorrow?

One of the most stubborn tenets of a strict Darwinian view of the world is that we are inherently selfish.  Thus, everything we do is to enhance our fitness, to get as many of our genes into the next generation as we possibly can, by hook, by crook, by wile and deceit.  Even if we help relatives, we are doing it only because they share our genes and, therefore, it's good for us. If we help strangers, that, too, is rationalized by the notion of reciprocity--we do it only because they'll help us later.  It's a 'theory' that can rationalize anything that seems at odds with it, a theory that can't be falsified!

Given all this, the June 29 episode of the BBC Radio 4 program Analysis, a discussion with philosopher Steven Scheffler of the idea of the collective afterlife, is an interesting one.  Scheffler recently published a book called Death and the Afterlife, drawn from a series of lectures, in which he in no sense means that we will have any kind of life after we have died.  He is concerned instead with the life that continues on without us, after our deaths.  He proposes a number of thought experiments to help elucidate how we feel about just that.

The BBC program began with two questions for the audience -- "Do you believe that people and the earth will continue to exist after your own death?"  And the second, "If you knew that Earth would be destroyed 30 days after your death by a collision with a large asteroid, would that change how you live your life?"  Another perspective on the same sort of question is what the detective novelist P.D. James wrote about in her 1992 book, The Children of Men, about the end of fertility in the human race.  The disease didn't threaten living people, but did mean the end of the entire human race. Would knowing that no humans would follow you on Earth change how you live your life?

Artist's impression of impact from a major meteor; Wikipedia

Scheffler believes that the afterlife, knowing that generations of people will follow us, matters more to us than we suspect and that upon pondering the question of how knowing the Earth would be destroyed soon after we die might change the way we live, most of us will come to realize that we might very well lose any sense of purpose, despite the fact that it's not our own life that is threatened. And this would change the way we live.  This means, says Scheffler, that much of what we do we do not for ourselves or even our children or grandchildren, but for unknown people who will come after us, because there will be people who come after us, and not just those we love.

Most obviously, if what you do now is something that isn't going to make a difference now but might in the future, would you continue doing it?  Would it make sense to keep working on finding a cure for cancer or reversing climate change if you knew there would be no one left to benefit?  But there would be other effects, Scheffler believes.  We would stop making art, or music, or creating literature, or writing history or doing any kind of scientific research.  If the issue was the infertility scenario posited by PD James, she suggests people would stop having sex, even when, as in her book, governments keep urging people to try, just in case someone somewhere hasn't been affected.  Scheffler says that he himself is sure he would stop writing papers about political philosophy.

He says, too, that the sense of horror we have about the end of the human race is different from the relative complacency most of us feel about the fact that everyone living now will one day be dead.

Boston Review quotes from his book:

My argument has been that personal survival already does matter to us less than we tend to suppose, and that the survival of humanity matters to us more. In saying this, I am not underestimating our powerful impulses to personal survival or the deep terror that many people feel when contemplating their own deaths. Nor am I denying the importance of self-interested motivations in ordinary human behavior. My point is that despite the power of these attitudes, there is a very specific sense in which our own survival is less important to us than the survival of the human race. The prospect of the imminent disappearance of the race poses a far greater threat to our ability to treat other things as mattering to us and, in so doing, it poses a far greater threat to our continued ability to lead value-laden lives.

Well, think about this from a Darwinian perspective.  A strict Darwinian could certainly twist it to fit theory perfectly well -- caring about the welfare of those who survive is completely in keeping with the urge to perpetuate our genes while we can.  Or, perhaps, we don't really believe we're going to die, so our caring is really about the usual reasons.

But I was talking about this with a friend the other day who is on the board of a number of conservation organizations, and is very active himself in nature preservation.  He said, "I have no children, so I sometimes wonder why I care so much about conservation.  Clearly, it has nothing to do with me."

A Darwinian might argue that he's doing it for his sister's descendants, to whom he's related, or even that he's related to the whole human race, so of course he cares.  But if we're related to everyone, and anything we do perpetuates our own genes, because all humans share genes, this trivializes the whole idea of "survival of the fittest," the backbone of Darwinian determinism.  It makes the 'theory' so generic that it loses any specificity and hence becomes in that sense essentially vacuous.

I think that there are so many exceptions to the Darwinian view of life as inherently selfish and self-perpetuating by now that it's past time to stop believing that these are exceptions rather than the rule. Humans aren't mere automatons driven by our genes' need to replicate themselves. Abortion, suicide bombing, birth control and the decision to remain childless, infanticide, altruism, even much human genetic or medical lab work which is unlikely to yield results for ourselves or even our children or grandchildren, are all behaviors that make no sense in a Darwinian world of direct self-interest.  And they aren't rare.

Culture is a powerful force.  With culture, we can talk ourselves into all manner of behaviors that have nothing to do with enhancing our survival or fitness, nor that of our relatives, and in fact might do just the opposite.  We can imagine an afterlife in the 72 virgins (or raisins, depending on your translation of the Koran) sense rather than Scheffler's, we can imagine future happiness without children, we can feel good about bringing a drowning swimmer to shore without expecting he or she will do something for us in return.  Janes can avoid killing anything at all, for spiritual reasons.  We need not kludge the argument to make all this into selfishness.  Culture, what we learn and agree with others about, matters.

Why isn't anyone looking for the culture gene?

On the mythology of natural selection. Part II: Classical Darwinism

Darwin didn't invent the idea of natural selection as a way of adaptive advance for traits in organisms that better suited their environmental conditions. But he basically coined the term and institutionalized the view that persists to this day, often invoked in a largely unchanged way despite 150 years of biological and evolutionary research. It was a strikingly perceptive idea, that others had had in previous decades (or, in some ways, even in the classical Islamic world; see our post on Ibn Khaldun), but only in rudimentary expression and not pursued, perhaps it seemed so obvious but also because there wasn't the kind of data, such as fossils and broad biogeographic knowledge, that led the insightful Darwin to generalize it into a basic worldview.

Darwin wanted to explain a purely material, historical process by which life could have evolved its remarkable complexity from rudimentary beginnings, no divine creationism involved (except possibly at the very beginning). The idea of a 'blind' screening force has penetrating appeal to anyone wanting a purely material understanding of our world. But to accept it you also had to accept the brutal heartlessness of that world. That of course went against religious promises of better things to come, of the truth of basic moral precepts, and so on.

To Darwin, and he was completely clear and explicit about this both in his writing (primarily, On the Origin of Species) as well as his private notes and letters, natural selection was a law of Nature, a universal force. That view is no surprise, because Darwin was a product of the post-Enlightenment world of science, ushered in by the likes of Galileo and Newton, in which science used examples and data to formulate precise laws that applied to everywhere beyond those examples. That also meant that in essential ways, it was a deterministic law of cause and effect. Caveats that might modify or soften that universal law were generally uttered in passing, but not really absorbed as an important part of the 'law'.

That dogmatic universalism still characterizes much that is in print in the public media but even in the professional journals, perhaps especially in the peripherally evolutionary fields like social science including our own Anthropology, but also in very technical fields like medicine, information sciences--and even a routinely invoked metaphor for almost anything.

The reason for this is that selection is a potentially all-powerful explanation that does not require foresight or immaterial factors and that to most people there is no alternative material way to explain the origin of complex organisms. But there are such ways, and there is much--very much I think--that we simply do not yet understand even about natural selection itself.

We'll discuss these alternatives, but first it's important to explain just what classical Darwinian selection is.

The conditions for natural selection
Natural selection is about cause and effect (that's what a law of Nature is). Here is a commonly accepted, widely used, textbook way to express that law:

Natural selection means the systematic differential reproductive success of competing organisms. The idea is simple: Since a species over-reproduces so that not all individuals in the next generation can go on to successfully reproduce, and since there is variation in form among that species, and since some forms of an organism do better in a particular environment than other forms, and since the reason for this is included in their heritable genome, and since the environment remains stable long enough over time for this form to be favored persistently, and since the favorable forms are also lucky enough to produce offspring who go on to reproduce, and since they produce more offspring than their competition, then those forms can become ever more common over time at the expense of their competition. Since all these contingencies do occur, indeed co-occur, then the more prolific life form will become more suited—better adapted—to the environment in question. Since the forms are sequestered from each other by some mating barrier, then they would diverge over time, and this was the explanation Darwin and Wallace proposed for the origin as well as specialization of species.

To many this may sound entirely correct and completely obvious. But in fact, surprisingly to many perhaps, it has zero scientific content. Since the assumption is that traits that are here are here for these reasons, whatever you see in the world must be fitted, and all you can do is try to find the details of any given case. It may or may not be a true description of how things are, but it is take-it or leave-it. 

Now compare that to this version:

Natural selection means the systematic differential reproductive success of competing organisms. The idea is simple: if a species over-reproduces so that not all individuals in the next generation can go on to successfully reproduce, and if there is variation in form among that species, and if some forms of an organism do better in a particular environment than other forms, and if the reason for this is included in their heritable genome, and if the environment remains stable long enough over time for this form to be favored persistently, and if the favorable forms are also lucky enough to produce offspring who go on to reproduce, and if they produce more offspring than their competition, then those forms can become ever more common over time at the expense of their competition. If all these contingencies do occur, indeed co-occur, then the more prolific life form will become more suited—better adapted—to the environment in question. If the forms are sequestered from each other by some mating barrier, then they would diverge over time, and this was the explanation Darwin and Wallace proposed for the origin as well as specialization of species.

This version asserts cause and effect in a scientific and testable way: If a cause is present, then the effect will follow. It is an assertion about the world that is so logical that if the conditions are correct, the conclusion must follow. In a sense it defines the conditions for adaptive change. But it doesn’t assert that those conditions actually exist: determining that is where the assertions become science.

Because of this, natural selection is always possible, and sometimes clearly occurring. But that doesn't mean it is occurring in any given case. But it is typically hard if not impossible to actually prove that the 'ifs' apply to a given situation. Indeed, weirdly and ironically, to say that selection is not occurring is almost a mystical and unprovable claim. How can you ever show that there is exactly zero difference in survival or reproductive output of one version of a trait or its underlying genotype compared to another? Since each individual and its circumstances (and its genotype) is different, what kind of evidence could you possibly collect?

In an experimental setting, you can approximate this with large samples, using clones (more or less genetically identical comparison strains) and so on. Even samples from the natural world can sometimes show sufficiently clear differences in fitness between traits or genotypes. Of course, even here the comparison is judged by some sort of inherently subjective statistical criterion, such as a 'significance' test--a topic we've written about before. But in some instances, nobody really argues, when it comes to clear-cut contemporary cases.

It's much more difficult when it comes to trying to give a classical Darwinian natural selection explanation for a trait that is here today, in terms of why it got here. Here we are often in the realm of almost pure story-telling (often, and often properly, derided as Just-So story-telling). We cannot directly observe the requisite ecological, population, competitive, and other aspects of the past, even at any one time, much less over the eons of time over which most complex adaptations seem to have taken place (the idea of Darwinian gradualism).

In fact, Darwin was trying to explain how organisms change to adapt to their changing environments, but by far most selection is about how organisms don’t change! Purifying selection, that is, selection against changes in the established traits (or their underlying genotypes) is far more pervasive and easier to detect (and more convincing) than ‘positive’ adaptive selection. That’s because we clearly find that known functional parts of the genome (that is, areas like regular gene protein codes) vary within and between species by far less than areas with less clear function. Finding DNA evidence for adaptive change is much more difficult—unless, of course, you view the genes being maintained by purifying selection as having got there by adaptive selection. But that view is often if not usually an assumption.

In fact, there are ways in which traits may sometimes, often, or even mainly be determined at any given time, and over evolutionary time, that would undermine even the invocation of conservation as one of, if not the criterion for biologically relevant function. We’ve written about that, but it is beyond our topic today.

When testable becomes ideological
Many biologists are enraptured by Darwinian selection, for various reasons. One is that it provides a satisfying dogma you can invoke without restraint and by assumption rather than any serious standard of proof. Making the assumption is often justified by stating some sort of physics-based general theory of the cosmos, such as that everything biological involves energy, and if something uses more energy than its competitor its fitness will necessarily be less--if you have to eat more than your competitor to maintain your body or genotype, your competitor will have an easier path to success. But an assumption cannot be offered as an explanation of any particular case, and cannot by its very nature be questioned (that's what an assumption is).  Even invoking the laws of thermodynamics or other physics theory were correct doesn't mean the consequence is detectable or meaningful in any given case--such as how much DNA a species' genome can tolerate that has no function, or trying to give an adaptive explanation for how many hairs there are on a rabbit's body.

Even the testable version of natural selection (the ‘if’ rather than ‘since’ version) is close to a tautology because when the ‘ifs’ are true then they are essentially the same as the ‘sinces’: it’s just another way of saying what is reproductively better reproduces better. This problem is widely known to philosophers of biology, and to some biologists, but the behavior and statements of many if not most biologists (including the human geneticists whose work is hyped daily by the media) suggests they’ve rather poorly understood this.

Of course, adaptive scenarios asserting competitive natural selection may be true, and indeed many are. And selection may be the explanation of a large fraction of traits that are here today. But that is not automatically so. First, we should be checking the strength of evidence for each of the ‘ifs’ that are at least implicitly invoked in any such story.

If the story is just offered invoking Darwin’s name or natural selection, without checking that evidence seriously, then what is being stated is an ideology, not science.

Even without being in any way incompatible with the general idea of adaptive evolution, there are a number of ways in which complex traits can arise and evolve in organisms that do not involve competitive Darwinian selection—nor creationism nor implausibly blind luck. We’ll turn to those next….

Challenges to reflex darwinian explanation...are they conveniently overlooked?

Darwin loosed much upon the world, with his systematic documentation of the idea that life evolved as an historical process of divergence from a common ancestral source, and that complex traits could arise by differential survival of inherited factors that construct organisms' traits.

No current explanation competes with this one.  Its realization had tremendous explanatory power.  It also had tremendous power to affect human society, and not always for the good.  It became an ideology: not only were some traits the result of natural selection, but essentially all were.  Natural selection was seen as a ubiquitous, highly focused and precise 'force'.  That led to the idea of value judgments: that we as intelligent products of this process could now help it along, by assessing what selection has liked or what was 'better' and say thus that such traits should be favored, by our giving the law of Nature a helping hand.

There are all sorts of logical problems with such reasoning, but it led people seen as authorities to define what was good and bad in this context and to make policy assertions about society in that context.  The eugenic era (the word basically meaning to help) led to many presumptuous abuses based on this sort of thinking that we know what Nature wants or what would be biologically better for our species.  The idea seems OK in principle, but we know that it led to awful abuses, and after the lessons learned by the Nazi policies based on rationales using academic advice of this sort, there was a revulsion against such genetic determinism.  It  may have gone too far in the denial direction, but it was based on an understanding of how an ideology can go terribly sour.

But now it's creeping back on little cat feet.  What is essentially strongly genetic determinism, driven by new genomic technologies, has led to a fervent belief that, so to speak, everything is determined by our genes.  A trait is explained by finding the selective factors responsible for it--that is, for finding those genetic variants (or assuming their existence) that lead to the most successful individuals.  It's an ideology, we would say, because it is too unquestioned, and there are many instances where we think that can be seen.

We discussed aspects of the relevance of this problem to issues of human race and racial variation on May 19.  That had to do with the dystopic uses of darwinian determinism.  But here are a couple of examples that show the issue in a different way.

Playboy bunny bodies and the Darwinian drool
There all sorts of theories about the traits involved in mate choice. It's a very sexy topic, so naturally it attracts a lot of 'scientific' interest.  It is all about sexual selection, an idea Darwin carefully documented from his point of view (mainly in non-humans).  But how deep is the thinking?

Lots of studies now and in the past have looked at purportedly representative samples of our species (that is, local middle-class 20 year-old college students) to see what gets them, er, excited.  How the face looks, the timbre of the voice, where the curvey parts or beefy muscles are. 

Mate choice would seem like the sincerest compliment, so close to evolutionary fitness (that is, reproductive success) that it can be a very strong molder of a healthy, hale, 'fit' and advancing species.  If you don't get chosen, well, bye-bye babies!  So one would expect that our ancestors had pretty much wrung all the variation out of such traits over the millions of years of our ancestry as humans.

We once heard a speaker, a licensed academic, say that the human ideal was the Playboy bunny type (this was, you'll have guessed, a male analyst).  This seems rather like the kind of assertion that is so wrong as to be laughable on the face of it.  After so many years of bunny behavior, at the heart of strong natural selection, we should all look like Hefner's dreams!  But any visit to a local mall or anywhere people gather shows how ineffective, that is, untrue, this assertion about sexual selection must be.  Not only are we not all like Playboy bunnies, but we're not even close.  Yet these aberrantly shaped people are having children!  Indeed, the actual rarity of this supposed Darwinian ideal is why there can be bunnies!

Still, pat selectionist explanations have such apparent appeal that this problem seems so easy to overlook.  And a story in the May 18 NY Times Weekly Review section reports a study that shows even more directly than a simple observation of human variation in the supposedly sexy traits, that these physical attractants, the immediate cues that a Darwinian viewpoint would argue are the flags of fitness, are not what has drawn people together who actually marry and stay (and have children) together.  Instead, those immediate sexy lures pale relative to compatible modes of interaction--getting along, shared interests, and so on. These traits are largely culture-specific, not driven by a  narrow set of highly adapted and selected genotypes. 

But, does a story that give any pause at all to the advocates of adaptive determinism via mate choice? 

There is a huge wealth of anthropologically well-known reasons why not all human males choose bunnies as mates (or, to be fair, bunnies choose football players), and why the widely asserted ideas of a prescriptively genetic basis for mate choice simply don't work.  The evidence against narrowly Darwinian accounts of human mating patterns is simply overwhelming, and yet somehow it seems very easy to conveniently ignore if you just don't want to see it.

The persistent sickness of the (ugh!) lower classes
We routinely see stories warning of the devastating potential of some current or impending epidemic of infectious disease among the poor people in the world.  We know that now and historically, the wealthy were spared much of the carnage of past epidemics.  They live in cleaner environments, are less crowded, with better nutrition, medical care, and the ability to get out of town when the epidemic comes.  The poor, well, since time immemorial they have been documented to suffer the mass deaths of plagues.

The evolutionary dynamics of infectious disease are widely studied, and again there are all sorts of very sophisticated selection-adaptation arguments for how the pathogen and the host (that is, people) co-evolve.  A massive epidemic leads to the survival of resistant people, just as massive use of antibiotics leads to resistant bacteria.  This is classic Darwinian selection and adaptation. 

But why, then, is it still the case that the poor are so vulnerable?  Given the heavy selective whammo of the long history of plagues, or cholera, or whatever, with some among the poor surviving while cart-loads of their peers ended up in pauper's graves, why aren't the poor as hardy as Superman?  Shouldn't we expect the rich to be the feeble, wobbly ones who are most delicately vulnerable, and doesn't what we actually see raise questions about how cogent are our models?

Of course, if you're a committed adaptationist, you can always make sure that the facts can be fitted to the narrow Darwinian view, by post-hoc arguments, selective use of data, and other tactics to defend a belief system against contrary facts.

We see the same sort of thing today more generally, in which assumed genetic causation of a tractably simple kind is at the core of much of the biomedical belief system.  Beliefs are treated as axioms--assumed truths--rather than ideas to be tested.  Once that's done, every fact is fitted to the assumption.  Studies generally are not designed to falsify our notions, as we self-flatteringly so often proclaim, but are in most ways designed to prove what we want to prove.

This message is not anti-Darwinian
We write often on this general problem.  But we are not at all anti-Darwinian.  Darwin's insight that life has evolved its diversity from a common simple origin through strictly historical processes was transformational.  Organized traits exist and must be explained in light of these facts.  The issue for us, as exemplified by the above examples is not whether sexual selection or infectious disease dynamics are potentially important, nor whether genomic variation related to individuals' traits or evolutionary process take place.  The issue is the tendency of the strength of commitment to lead investigators to force pat explanations onto a world that isn't so pat.

In principle, the questions could be posed in perhaps a more productive, less ideological way.  We do, after all, have shapely bodies, different color hair and eyes, curvy organs and protuberances, and so on. Epidemics surely affect those most susceptible who are exposed.  If these traits are not involved in fitness, then why do we have them?  This is a legitimate question, actually a lot more interesting and deserving of more serious consideration than the simple declarative explanations. 

Likewise there is the important issue of what studies to believe and what ones to dismiss.  That the Times reports a study saying that sexual body traits don't actually determine mate patterns may or may not be a good study, just as claims of Playboy mate choice may be based on weak evidence.  The issue is one of a more dispassionate evaluation of evidence and a more assumption-neutral way of designing studies.

When science is really making advances, you start to see committed devotees of some theory begin to accept that it may not be so after all.  But, the way humans cling to beliefs, even in science as in other belief-based areas, don't hold your breath.

Ism-itis!

People adhering to a particular faith, say X, are often called Xists or those who believe in Xism.  Sometimes this is just a descriptor, but often it's used as a criticism, or worse.  That's what happens when pole-headed right-wingers call President Obama a 'socialist' (something the pole-heads apparently know nothing about).

Sistine Chapel; Wikimedia Commons

This kind of ism/ist description applies in cultural combat but also in science.  Thus people can be reductionist, frequentist, or falsificationist and so on, in the words of their detractors -- so these aren't compliments.  People actually would not use the word about themselves if they feel that others use the term in a derogatory way.

Creationists (and they really are ists in the sense of holding tightly to a specific ideology or creed!) often denigrate people who understand the real world as 'evolutionists',as it is not clear exactly what these terms mean, which can be important.  It is a castigating characterization when used by creationists, and it may imply that one is an ideolog about, rather than an explorer of, the subject of evolution.

We often refer critically on MT, to evolutionary or Darwinian or genetic 'determinists' or 'determinism.'   However, our meaning is important to understand.  At a seminar in our department a couple of years ago, when we questioned the nature of genetic determinism being invoked in some darwinian adaptive Just-So story-telling, someone stated that he was a determinist--"and isn't everyone?" Well, in science the answer is clearly yes, and no.

Here's where language gets in the way.  If determinism means that Nature is causal and that every effect must have some cause, then most scientists would plead guilty to the charge.  To invoke effects without cause is to be mystic, and certainly that has nothing to do with science.  That doesn't mean that we have identified or understand the causation of effects under discussion, and there is where the legitimate issues lie.

Darwin, Museum of Natural
History, London;
Wikimedia Commons

Things are less transparent when it comes to 'selectionism'.  If one makes the Darwinian assumption that whatever is here had to have got here by adaptive natural selection, then it is perfectly legitimate not to be a selectionist.  Much in evolutionary reconstruction is of this type, and it often includes behavioral evolution or even morphology, where traits themselves can be hard even to define. If the trait must (by assumption) be the result of specific adaptive natural selection, then our task is to identify that selection.  But we can always find some such reason, since the function today can be equated to having been the advantageous function in the past.  This is entirely circular, and it's not science!

This doesn't mean that eyes or birds' wings or hominid locomotory apparatus got here 'by chance', as creationists still falsely often suggest, but it can mean that some functional elements ended up in our genomes by chance, if their initial harmfulness or helpfulness was slight compared to the populations they were in (in genetic terms, they got into the genome by 'drift').  Duplicate genes that have no harmful effect but provide redundancy that can subsequently be used for new function constitute one of many examples.

Selection must build on what's there, however it got there.  Such chance-installed elements don't suddenly produce wings out of reptilian forelimbs, because complex traits involve too many changes.  But the elements themselves need not have got here by selection, since most will have slight effect.  Likewise, truly harmful things are eliminated by not being viable, and that is a form of selection, but not Darwinian or adaptive selection, since the defunct forms weren't really competing with anybody or anything.  They just didn't work.

The bottom line here is that determinism depends on the degree to which (1) truly probabilistic cause exists, and/or (2) one believes that a specific cause under consideration perfectly predicts a specific outcome, and/or (3) the cause acts alone but only has predictive power if very accurately measured, and we can't get such quality measures.  If a causal effect is truly probabilistic, it does not in the usual sense 'determine' the outcome.  And if the cause is but one of many contributors, and hence has weak predictive power, or does so if inaccurately measurable, then arguing for 'determinism' stretches the truth and merits criticism.  It doesn't mean there is no cause, but in these instances we cannot reliably or accurately predict the outcome from observing the cause. 

Likewise for adaptive selectionism or 'Darwinism'.  If selection is weak, sporadic, erratic, or distributed over many different contributing factors, or if there is no selection but only drift, or if there is selection but we have no serious way to argue what its mechanism was, then the adaptationist argument stretches the truth and merits criticism.  Knowing the genes involved in a trait doesn't predict their change from on generation to the next and, indeed, different genotypes can generate the same phenotype, so that we cannot infer the cause from the result.  Again, this doesn't mean there is no cause, but it does mean that selectionism is over-stated.

What we argue when criticizing what we think are excessive claims of genetic determinism or selectionism is that the assertion being made does not bear scrutiny in these above senses.  We're not arguing for mystical causation or effects that are not 'determined' by physical causes.  We may be arguing that we have little idea or way of knowing what the cause(s) was or were, or that the assumption of a kind of causation can be made self-fulfilling rather than really scientifically testable.  It often seems to be true that based on methods and criteria we use today, some of these causal situations simply cannot in principle be worked out beyond some very imperfect level of precision.  Things too probabilistic, or too weak to be understood from the kinds of samples we can actually collect, are simply not accurately predictable from observing putative causes, and that also means we have inadequate ways of even identifying the causes.

We do seem to live in an orderly causal world.  There are 'laws' of Nature, even if the word is a human one that doesn't imply a law-giver.  Whether causation can be truly probabilistic, and whether there may be causal aspects whose very existence humans have not learned to detect or characterize, we have no idea.  Nor does anybody else.  There are wild theories of multiple universes to get around pure probabilistic causes, and things like dark matter and energy to get around some of what we observe in ordinary matter.  Who knows what else someone may some day discover.  Given this, we believe that more circumspection is in order about causal claims in the life sciences.  In part this is because science has practical implications for society, can be used towards evil or harmful ends (even if unintentionally), and costs resources that could be used for other things, if we had a less lobbying-based or ideological social environment in terms of making such decisions.

To argue that someone is a 'determinist' is not to label them with a slur as if they should instead by a mystic or crystal ball reader.  It is to argue that assertions should be tempered, and we should take more seriously the things that are clearly inadequately known but could be quite fundamental.  To be a 'Darwinian' or 'adaptationist' can mean not just that one recognizes the clear truth of evolution as a fact, and that survival requires success by definition, but can refer to someone who goes beyond that, to and assumes what is to be shown, and that certainly is not good science.  One wants to have an interpretive framework, without which science would be difficult if not impossible, but the framework needs to be tested rather than assumed.

Assuming a framework--being an 'ist'--may be good for hustling attention or grants, but not for a more serious--if avowedly less complete--understanding of things that we now have or than the ists of this world would lead you to believe.

Leave me alone or I'm going home!: The Heisenberg uncertainty principle in evolution and epidemiology

To a non-physicist, the gist of the Heisenberg uncertainty principle, or the observer effect phenomenon associated with it, is that studying an object changes the object.  You want to know the position and movement of a subatomic particle, say, but to find that out you have to study it with energy, like a light beam, which allows you to identify the position by seeing how the collision with your measurement beam occurs. But that alters the target particle's movement so you can't know both.

Similar kinds of issues apply to modern-day epidemiology.  We referred to this yesterday in a comment about the effect of maternal drinking during pregnancy affecting the future of their offspring.  A Heisenberg analogy for epidemiological studies goes like this:  if by studying something that has many contributing risk factors, the persons being studied change their behaviors, and thus their exposures because they know the results of the study, you can no longer estimate what the exposure risks will be.

Often, the change in behavior is of a magnitude that it's a major effect relative to the signal that's being studied.  If you stop eating pork because a study says that eating pork gives you a somewhat increased risk of warts (it doesn't--this is just a made-up example!), then the effects of pork-eating will be changed by virtue of the exposure change and the knowledge that this is being studied.  If this happens often enough--as it does with our 24/7 many-channel news reports--then tracking risks or measuring them becomes very problematic, except for the really major risk factors (like smoking and lung cancer) which are robust to small changes.  The science and the scientist become part of the phenomenon, not the external observer that they need to be to do the science.  This leads to many of the serious challenges to modern epidemiology, behavior, education, political, economic, etc. studies, including those of genetic causation.  And since trivial risk factors are mis-reported in the news as big ones, the signal-noise ratio is even less favorable to clear-cut conclusions.

There is a kind of Heisenberg analog in evolutionary terms, too.  If relative fitness--reproductive chances--are affected by both genome and ecologic contexts, and the differences are small, then what happens tomorrow to a given genetic variant, is highly dependent on all sorts of environmental or other genotype changes. A given variant won't have the same relative effect tomorrow as it did today, and since evolutionary models are about relative fitness, the evolutionary landscape changes.

This becomes Heisenberg-like not because it's about observer-interference effects in this case, but because the context changes can be as great or much greater than the net fitness advantage of a genetic variant.  This means fate-prediction is difficult, and in this case the observer analog has to do with the screening-efficacy of natural selection.  Changes in the frequency of an allele can change its net fitness effect.  When fitness (like electron positions?) is not just contextual but essentially probabilistic, something that affects position (current relative fitness) affects evolutionary trajectory.  That's one reason evolution is  essentially unpredictable, except under unusually strong conditions, and in that sense not deterministic as it is viewed in the usual Darwinian concept, especially as put forward by those not versed in evolutionary theory--and that includes many biologists and all the blathersphere that invoke Darwin or natural selection in making pronouncements about society.

The arrogance of science.

We have not read Sam Harris's new book, the soon-to-be bestseller, The Moral Landscape: How Science Can Determine Human Values, but we have watched his TED lecture on the subject, and read Appiah's review in the Sunday NYT and we're pretty sure we're not likely to read the book.  But of course that isn't stopping us from having something to say about it.

Two things disturb us about Harris' argument.  (If you've read the book and can tell us that reading it would change our minds, please let us know -- we'd love to be wrong on this.)  But as we understand it, Harris's argument is both arrogantly imperialistic -- or worse -- and non-Darwinian, which is rather ironic from someone arguing that science will out the Truth. The 'logic' of the argument is to put together intelligent-sounding phrases that have little actual content....especially little scientific content.

Best known as one of the New Atheists, Harris has written previously on how he knows there is no God.  He argues in his new book, and in the lecture, that only science can answer the questions of life's "meaning, morality and life's larger purpose" (as quoted in the review).


Which prompts us to ask, Where is existentialism when we need it?  Better yet, let's call it Darwinian existentialism.  If we are truly to take the lessons of Darwinian evolution to heart, we must accept that there is no "larger purpose" to life.  The only purpose to life, which we don't ourselves construct, is to survive and reproduce.  And even that is not a purpose to life itself, which to an arch Darwinian might be not to survive, so something better can do it instead.  Or to expend solar energy in some particular way.  To argue otherwise is to position humans above Nature, which is precisely what Darwin and his contemporary supporters argued was biologically not so (though even Darwin fell into that ethnocentric trap in Descent of  Man).

Further, if we accept Darwinism in the raw, there is no meaning or morality for science to find. Meaning, morality and purpose are constructed by us once we've got food and a mate. As animals with history and culture and awareness of both, we imbue our lives with values and morals and meaning, but they are products of the human mind.  This doesn't mean that they aren't important, or compelling, or even things to live or die for, but those judgments are our own.  But people with the same genome can adopt very different sense of meaning -- which is equally important and compelling.

According to Harris, science can uncover not only facts, but values, and even the 'right values'.  Just as science can tell us how to have healthy babies, science can tell us how to promote human 'well-being'.  And "[j]ust as it is possible for individuals and groups to be wrong about how best to maintain their physical health," he writes, as quoted in the review, "it is possible for them to be wrong about how best to maximize their personal and social well-being."

What is this well-being of which he speaks?  Who says we or anyone should 'maximize' it, and who are 'we' in this context?  Well-paid professors?  If he meant Darwinian fitness we might pay attention because that's the only objective measure of success that counts in a Darwinian world (unless it's ecosystem expansion, even if at the expense of particular species).  But what he means is something much less empirically tangible -- ironically for someone arguing that science will find it.  He means happiness.  This would be perfectly fine in the realm of psychology or Buddhism or philosophy, but, to our minds, this argument of his is on the same playing field with religious arguments about morality and purpose -- which of course he would not accept -- and even pre-Darwinian.

And, it wasn't that long ago that Science decided that homosexuality wasn't an illness to be cured, or that phrenology wasn't in fact enlightening, or that bleeding patients wasn't a cure -- and of course there are many other such examples.  When what was once True becomes False, what does this say about Science and its ability to find the ultimate Truth? Why would anybody think we're right today....unless it's from ethnocentric arrogance?


The Enlightenment period was the age in which the belief grew that modern science could be used to create a better world, without the suffering and strife of the world as it had been.  It was a world of the Utopians.  Their egalitarian views were opposed vigorously by the elitist right ('we're just scientists telling it like it is')  in the form of Thomas Malthus, Herbert Spencer, strong Darwinians, who opposed the more idealistic thinking.  The Science Can Find the Moral Truth view grew through much of the 19th century, but its consequence, 'modernism', was rejected after science gave us machine guns, carpet bombing, eugenics, the Great Depression, dishonorably wealthy industrial barons, and other delights of the 20th century.  The reaction to that went under various names, but included things like cultural relativism and anti-scientific post-modern subjectivism.  Unfortunately, like any Newtonian reaction, the reaction was equally culpable, if less bloody, in the opposite direction, by minimizing any reality of the world.

Cultural relativism, against which Harris rails, is the view that each culture is a thing of its own, and we can't pass judgment about the value of one culture over another, except as through our own culture-burdened egotistical eyes.  That is not the same as saying that we have to like someone else's culture, nor adopt it, nor need it be a goody-goody view that we have to put up with dangers from such culture (like, for example, the Taliban).  But there is no external criterion that provides objective or absolute value.   Racism and marauding are a way of life in many successful cultures; maybe by some energy consumption or other objective measure it's best for their circumstances.  Science might suggest (as it did to the Nazis and Romans and some groups today) that their way is the only way, the best way, Nature's chosen way.


Science may be a path to some sorts of very valuable Truth, and better lives, such as how to build a safe bridge or have painless dentistry (the greatest miracle of the 20th century!).  Regarding many aspects of our culture, we would not trade.  We ourselves would love to attain the maximum happiness that Harris describes.  But it is an arrogance to assume that in some objective sense that is 'the' truth. 

And what if the 'facts' said that to achieve the greatest good for the greatest number (not exactly an original platitude, by the way) meant that people like us (and Harris) had to cut our incomes by a factor of 100, or 1000, for resources to be equitably distributed?  After all, the USSR implemented 'scientific' ideas of maximal good for the masses (communism, Lysenkoism, to the tune of tens of millions purged, frozen to death in Siberia, or starved because of failed harvests, and more).  The Nazi policies were explicitly based on the belief that Aryans were simpler better than others, based on warped Darwinian truths, and we know what happened.

So, anyone who would still not realize that the smug self-confidence that one can find the ultimate truth through science either is another tyrant potentially in the making, or hasn't read his history.

Whether or if there can be some ultimate source of morality is a serious question and if it has an answer nobody's found it yet.  Religion has no better record than materialistic science, nor secular philosophy.  Nor does Darwin provide that kind of objective value system, especially in humans where very opposed cultural values can be held by people toting around the same gene pool.

The Darlings of the Smug rise, like mushrooms, in every society.  They are glib, but so are demagogues of other sorts.  They're all potentially dangerous -- or are those for whom they serve as the intellectual justification.  Again, that is not to say we should adopt someone else's values, nor that we should hold back from defending ourselves against those who threaten us.

Still, oblivious to these points, Harris argues, as does the far right in the US, that cultural relativism is wrong and should be completely and utterly discounted.  Here are some quotes from his TED talk:

How have we convinced ourselves that every opinion has to count?  Does the Taliban have a point of view on physics that is worth considering?  No. How is their ignorance any less obvious on the subject of human well-being?  The world needs people like ourselves to admit that there are right and wrong answers to questions of human flourishing, and morality relates to that domain of facts.  It is possible for individuals and even for whole cultures to care about the wrong things.  Just admitting this will transform our discourse about morality.

Again, how is this different from, say, the Aryan line which would say we have a right to decide and purge, all in the name of science (and, by the way, it was medical science as well as Darwinism)?  Why is this not the arrogance of imperialism all over again?

When the Taliban, the religious right and the likes of Harris and the New Atheists all believe that only they are the keepers of the Truth, dominion can be attained not by science but by wielding of power alone.

Blame it on Darwin?

Ken took part in a panel discussion recently about Nazi medicine and eugenics. The three participants on the panel were a lawyer who has done work on the legalities of torture, a historian of Nazi Germany, and Ken, a geneticist with interest in ethical issues. The discussion was led by a moderator, also a historian of Nazi Germany. This was in conjunction with a traveling exhibit, "Deadly Medicine," (logo at left) from the US National Holocaust Museum, that had been here at Penn State, and most of the attendees had seen the exhibit.

This was the third in a series of discussions of the importance of eugenics in Nazi Germany. Previous speakers had talked about the extermination programs that started, with the full cooperation of German physicians, with the elimination of mentally or physically disabled infants and children, and expanded to include many other members of society.  The latter part of the history is well-known to most of us, but the acquiescence of the medical system is less so.

This third evening started with a discussion of the history of eugenics and how it came to motivate the Nazis. Ken traced it back to Darwin, and the idea of survival of the fittest, which was quickly translated into the social arena (mainly not by Darwin but by others), reinforcing existing class-society ideas whereby the richest, smartest, most powerful are best for society, while having to maintain the poor and the ill is an endless resource burden on the stronger members of society. This burden not only seemed unfair (to the rich and smart and powerful), but the cost of support for the weak, ill, insane, or otherwise undesirables would be a permanent drag on a society that wished to be its best. Thus, in implementing government-driven eugenics (sterilization and eventually murdering the 'undesirables'), the Nazis believed -- or, rationalized -- that they were doing what was right for their country by culling the less fit. Germany would become the #1 country in the world. Deutschland uber alles!

Darwin's ideas, and a strict adherence to the view that human individual or 'racial' traits can be judged to have more or less value and, because of evolution, are inherent, led scientists to decide that whereas Nature had made those judgments in the past, we (the scientists) are the ones whose duty it is to make them in our scientific age. The historian on the panel agreed about the importance of the eugenics movement in Germany at the time, and added that for cultural reasons the medical system was especially well-situated (or unfortunately situated) to support the cleansing of society in this way. Doctors did a lot of the dirty work, signed off on even the worst horrors, and gave the stamp of respectability to much of what happened.  This history is well-known, but perhaps less so to the younger generation, which is why the 'Deadly Medicine' exhibit was brought to Penn State, and why there were three different events discussing its meaning.

In any event, the panel moderator finally noted that Darwin's name had been mentioned a number of times during the evening, and asked whether it was fair to conclude that Darwin should be blamed for the Holocaust. Darwinism is still used as a justification for making value judgments about human traits, including races, and for justifying inequality as a natural state of Nature. This is in fact an idea that has been widely promulgated by the extreme right wing in the US, and by Creationists. Ken's response was that blaming Darwin for what people did with his ideas would be like blaming Benjamin Franklin for the electric chair. This of course won't diminish the blame the right wing and religious fundamentalists bestow on Darwin for all of society's ills, because this is an ideological struggle, not one based on facts -- and of course Darwin's real sin was claiming that humans were not created by God in their present form.

But still, there are many lessons to be learned from the eugenic age for us in our own genetic age. Evolution, too, is an idea that is out there and can't be undone. We are not likely to repeat the same horrors of the original eugenics age, but new genetic data and the belief that genes determine your nature, can easily be misused in our own new ways, and there is no guarantee that those ways will all be benign. Our society will face the issues related to this, such as confidentiality of genetic data, the use of such data in governmental monitoring of citizens, in policies related to insurance and in many other ways. Many investigators are analyzing data on human variation in ways that are, perhaps unintentionally, almost identical to the categorical ways our species' variation was treated a century and more ago. Ken has a couple of papers in press that point this out.

So, whether remembering history actually discourages people from repeating it or not, we think it's incumbent upon practitioners of genetics and anthropology, which of course has its own entangled past with the Nazi regime, to know the history of their disciplines, and to be aware that it wasn't all pristine.

For God's sake!

We have just reviewed a book by CE Cosans, called Owen's Ape & Darwin's Bulldog: Beyond Darwinism and Creationism (Indiana Univ Press, 2009). It's an interesting discussion of the famous debate between Darwin's public (pugilistic) advocate, TH Huxley, and Darwin's opponent Richard Owen (founder of the British Natural History Museum). The question was whether humans have distinct anatomical characters compared to apes (genes were not known at the time).

The brain, naturally, was the organ of interest. Huxley claimed that there were only quantitative differences between the anatomy of ape and human brains. Owen claimed distinct differences, including a structure called the hippocampus minor. The debate was long, public, and bitter. In the end, because Darwinism won the nature-of-life debate, Huxley is treated as the winner of this debate, too. But Cosans provides good evidence that, considering their worldviews and what they actually said, Owen's interpretation was perhaps closer to the anatomical truth. Cosans analyzes the history in terms of theories about science and its relationship to the empirical world and our interpretations of it.

The analysis of this history is fine, but Cosans also delves into what Darwin, Huxley, and Owen believed about God (and hence his subtitle). This is only peripherally relevant to the main event, the debate about anatomy. It makes a saleable subtitle, and we guess that these days nobody can simply leave the religion vs 'creationism' fight alone.

The point here, however, is not who believes what and why in that regard, but that the religion debate provides a distraction, that we constantly see these days, away from the merits of the various scientific cases. In particular, we should no longer be concerned as scientists about what Darwin's or Huxley's personal religious views were. Darwin's writing is of interest to history, certainly, but not as a sacred text (though one to be revered, to be sure!).

What we think today about biology and its nature needs to be evaluated in terms of what we know and what we can testably speculate about. The gravitational pull of gossipy food-fights is natural, since even scientists are human. We have enough trouble being objective about the science itself, such as the relative roles of natural selection, population structure, environmental change, and chance in the nature of life. But too often we relate these discussions to irrelevant, but often highly emotive, sideshows.

We don't need that in order to struggle with truly fascinating questions such as what makes humans seem so different from other animals, despite great similarities in our genomes!