Evolution-5: How probability intuition can lead us astray

(See part 1, part 2, part 3, and part 4.)

One of life’s ironies is that the difficulty in understanding the mathematics of Darwin’s theory of natural selection may actually be caused by natural selection itself.

As we saw earlier, natural selection does not try for maximum benefit but instead works on a ‘just good enough for now’ principle. Steven Pinker in his book How the Mind Works (1997) is a cognitive scientist who believes that natural selection has been the driver for most aspects of our bodies and our behavior, and that the brain, being just another organ, has evolved to do what it does to effectively meet the challenges it faced at various times in our somewhat distant past. Pinker points out that humans, when compared with other animals, have unusually large brains compared to body size but that this rapid expansion in brain size occurred more than 100,000 years (or about 5,000 generations) ago (Pinker, p. 198) and then leveled off after that. This means that the structure of our present brains has been largely determined by a time when humans were hunter-gatherers and foragers.

This means that although modern life is undoubtedly very complex and require us to meet a vast array of challenges, our brains are best suited to meet the challenges of our ancient forebears, not those of driving on a highway or learning to operate a computer or solving sudoku puzzles. Thus we are very good at identifying faces and shapes, seeing things in depth, reacting to predatory dangers, and acting on instincts such as ducking when an object is thrown at our heads, etc, because our brains have probably evolved modules that handle such things efficiently. But we are not so good at solving quadratic equations. The kind of mathematics that helped our hunter-gatherer ancestors survive did not require much beyond an elementary sense of number. As for probability, simple concepts largely based on induction and extrapolating from past experiences, are sufficient.

But as culture developed in the last 10,000 years with the advent of more settled agrarian societies and written language, we now find ourselves having to struggle a bit to master the concepts needed to face today’s challenges. They do not come ‘naturally’ to us, by which I mean that there are no brain modules that have evolved to enable us to quickly grasp and understand and respond to them.

This is especially true of probability and statistics. There was no need for our ancestors to develop modules to make Bayes’ Theorem or the Central Limit Theorem easily understandable, which explains why our intuitions are so often led astray. For example, many people fall prey and lose money because of the ‘gambler’s fallacy’ because they put their faith in a spurious ‘law of averages’, believing that the more repeated occurrences you have of the same thing (say getting heads on a coin toss or coming up black in a roulette wheel), the more likely a different outcome becomes on the next play. Similarly people who play the lottery numbers tend to avoid numbers that have won recently.

While mathematical sophisticates may look down on such naïvete , Pinker points out that such expectations are perfectly consistent with the kinds of probability experiences our hunter-gatherer ancestors experienced and which we still experience in most everyday life. After several days of rain, a dry day is more likely. After seeing several elephants appear in a line, it was more likely not to see one. In fact, event repetitions that are finite and terminate and change are the norm in nature, not the exception. Hence believing such things and acting upon such beliefs has some survival value that makes it plausible that our brains evolved modules that encoded those expectations, making us instinctively sympathetic towards believing things like the gambler’s fallacy.

The reason that so many are fooled by the gambler’s fallacy is that the creators of the gambling devices go to great lengths to make each event independent of the previous ones, thus violating our natural expectations. We thus have to consciously learn to sometimes go against our ‘natural’ instincts and this takes effort and is not easy.

Even though I consider myself fairly adept at mathematical manipulations, I am often humbled by how easily my intuition is led astray when confronted with a novel statistics problem. Take for example this case, which may be familiar to people who have taken an elementary statistics course, but fooled me when I first encountered it.

Suppose the incidence of some disease is fairly rare in a population, say about one in a thousand. You are told that there is a test for this disease that is pretty good in that it that has a ‘false positive’ rate of only 5%, meaning that if a randomly selected group is tested, only 5% of the people who do not have the disease will have test results that come out positive. Also you are told that the false negative rate is zero, meaning that if someone does have the disease, the test will definitely come out positive.

Suppose you are among those who are part of this random testing. To your dismay, the result is positive. What do you think are your chances of actually having the disease?

Most people would think that it is very high. They may put it as high as 95%, thinking that if there is a 5% false positive rate and 0% false negative rate, that means that the likelihood of someone testing positive having the disease is 95%. This sounds eminently reasonable.

But the actual chance of you having the disease despite testing positive is just 1 in 51 or less than 2%! How come? This becomes easier to understand if we shift from talking in terms of probabilities (which I have pointed out are not so intuitive) to talking about numbers. Suppose you are one of 1000 people being randomly tested. (Any size will do. I have chosen 1000 because it is a nice round number.) Then an incidence of 1 in 1000 means that we expect only one person to actually have the disease (and who will test positive), and 999 to be free of the disease. But a 5% false positive rate will result in about 50 of the 999 people who do not have the disease also testing positive. So your chance of actually having the disease is the chance that you happen to be that one person with the disease out of the 51 testing positive.

What the positive test result has done is provide a twenty-fold increase in the odds of your having the disease from 1 in 1000 (or 0.1%) to 1 in 51 (or slightly less than 2%), but your chances are still extremely good (over 98%) of not having the disease. I suspect a lot of people get unduly terrified by test results of this kind because doctors may not know how to present the data in ways that give them a better sense of estimating the probability. (Of course, I am assuming that you were selected randomly for this test. If the doctor recommended that you get the test because you had other symptoms that caused her to suspect you had the disease, then that would further increase the odds of you having the disease.)

The lesson here is to be wary of our ‘gut’ feelings when dealing with certain mathematics concepts, especially involving probability and statistics. This may partially explain why Darwin’s theory of natural selection, dealing as it does with small probabilities and long time scales, is so hard for many to digest because they are outside the range of things we experience on a daily basis. In future postings, I will look at some of the issues that come up.

POST SCRIPT: Sicko opening nationwide on Friday

Michael Moore’s new documentary on the health care system Sicko will be at the Cedar-Lee (2163 Lee Rd) in Cleveland Heights starting on Friday, June 29, 2007. The show times are noon, 2:30, 5:00, 7:30, and 10:00 but you should check before you go.

Moore also appeared on The Daily Show to point out once again what a scandal the health care system in the US is, where it is actually in the interests of the profit-driven health insurance companies to deny health care to patients.


If you read some of the more thoughtful analyses of the reasons behind the 9/11 attacks, you may have noticed repeated use of the word ‘blowback’. Some may not be aware that this word is used by the CIA to denote the consequences that its covert activities abroad might cause, and the disasters they might someday bring down on the US.

The idea that one’s actions have repercussions is perfectly sensible. It is absurd to think that US foreign policy, especially when it is used aggressively and militarily and covertly to interfere in the internal affairs of other countries, will not give rise to opposition and antagonism that may manifest itself in unexpected and unconventional ways.

This rational view of how actors behave on the world stage is excoriated by those demagogues in the media (by which I mean the major political leaders and pundits) who prefer to couch foreign policy debates in simple dualistic good-and-evil terms, and to suggest that the ‘evil they’ hate the ‘good us’ simply because of our virtue.

The word ‘blowback’ and its associated meaning moved from the murky clandestine world and entered the popular culture when it was used as the title of an influential book Blowback: The Costs and Consequences of American Empire published in 2000 by Chalmers Johnson. Johnson is a former CIA consultant and a professor of Asian studies at Berkeley, and was an avowed cold-war warrior during the Vietnam war era.

Johnson has now written a very interesting article titled Evil Empire: Is Imperial Liquidation Possible for America? on the current state of affairs. The whole article is quite long but well worth reading but here are some excerpts:

The United States, today, suffers from a plethora of public ills. Most of them can be traced to the militarism and imperialism that have led to the near-collapse of our Constitutional system of checks and balances.
. . .
If these people actually believe a presidential election a year-and-a-half from now will significantly alter how the country is run, they have almost surely wasted their money. As Andrew Bacevich, author of The New American Militarism, puts it: “None of the Democrats vying to replace President Bush is doing so with the promise of reviving the system of check and balances…. The aim of the party out of power is not to cut the presidency down to size but to seize it, not to reduce the prerogatives of the executive branch but to regain them.”

George W. Bush has, of course, flagrantly violated his oath of office, which requires him “to protect and defend the constitution,” and the opposition party has been remarkably reluctant to hold him to account. Among the “high crimes and misdemeanors” that, under other political circumstances, would surely constitute the Constitutional grounds for impeachment are these: the President and his top officials pressured the Central Intelligence Agency to put together a National Intelligence Estimate (NIE) on Iraq’s nuclear weapons that both the administration and the Agency knew to be patently dishonest. They then used this false NIE to justify an American war of aggression. After launching an invasion of Iraq, the administration unilaterally reinterpreted international and domestic law to permit the torture of prisoners held at Abu Ghraib prison in Baghdad, at Guantánamo Bay, Cuba, and at other secret locations around the world.

Nothing in the Constitution, least of all the commander-in-chief clause, allows the president to commit felonies. Nonetheless, within days after the 9/11 attacks, President Bush had signed a secret executive order authorizing a new policy of “extraordinary rendition,” in which the CIA is allowed to kidnap terrorist suspects anywhere on Earth and transfer them to prisons in countries like Egypt, Syria, or Uzbekistan, where torture is a normal practice, or to secret CIA prisons outside the United States where Agency operatives themselves do the torturing.

On the home front, despite the post-9/11 congressional authorization of new surveillance powers to the administration, its officials chose to ignore these and, on its own initiative, undertook extensive spying on American citizens without obtaining the necessary judicial warrants and without reporting to Congress on this program. These actions are prima-facie violations of the Foreign Intelligence Surveillance Act of 1978 (and subsequent revisions) and of Amendment IV of the Constitution.

These alone constitute more than adequate grounds for impeachment, while hardly scratching the surface.

It is a measure of how weakened the Congress has become that it has failed to seriously consider impeachment of the President despite having a very strong case for doing so. Only Congressman and Democratic presidential candidate Dennis Kucinich has made any moves to at least impeach Vice President Cheney.

POST SCRIPT: The flourishing of nonsense

Not heard about best selling self-help book The Secret? These two funny guys from Australia explain what it is all about and take the correct attitude towards it. (Thanks to Onegoodmove.)

One reason that religion is a negative influence in society is that it enables other evidence-free beliefs to flourish in its wake, because it creates a climate where vague mystical and supernatural forces are given credibility. How else can one explain the vast numbers of people who take stuff like The Secret seriously?

Materialists can dismiss this stuff as nonsense because it invokes some mysterious and unknown agency that intervenes in the world in response to human requests. But on what basis can someone who believes in a personal god do so, even if they wanted to? Isn’t The Secret based on prayer and faith, just like religion?

Evolution-4: Darwin gets an idea from Malthus

(See part 1, part 2, and part 3.)

In Darwin’s travels to distant lands from 1831 to 1836 on the Beagle, the different climates and environmental conditions he encountered made him aware of the weakness of the existing theory of ‘special creation’, where god was assumed to have created creatures best suited for their environment. Darwin saw for himself that very similar climates could produce hugely different kinds of species, and that the nature of these species seemed to be more influenced by the species in nearby areas than by anything else. This seemed to him to suggest that new species arose from the modifications of the old.

The discovery that the Earth was much older than had been previously thought, and the evidence for which was in the geology book by Charles Lyell that he had read on the boat, told him that it may be possible for these changes to occur gradually by very small steps provided that there was enough time for the changes to accumulate.

But why should species change at all? Why shouldn’t they stay the same forever? Or if they changed, why wouldn’t they change randomly instead of seeming to have a direction towards increasing complexity?

What Darwin still lacked was a mechanism that drove the change in organisms. The idea for this came in September 1838 when, after his return from his voyage and he was thinking about all the evidence he had gathered, he read Thomas Malthus’s Essay on the Principle of Population in which that political economist argued that the only thing that kept the population of anything (humans, other animals, plants) from experiencing runaway exponential growth was the limitation of essential resources (such as food and suitable habitats), and deprivations such as cruel climates, predators, and the like. (David Quammen, The Reluctant Mr. Darwin (2006), p. 42.)

Darwin knew that the size of plant and bird and animal populations in nature were fairly stable and he reasoned that the factors identified by Malthus might act differentially on members of the population, being more likely to remove the ones less suited and thus increasing the proportions of those more suited to the conditions. This kind of selection pressure, he felt, must be the driver of evolutionary change. Here at last was the mechanism that he had been seeking.

For the next twenty years, he carefully studied this process, starting with the breeding practices of pigeon owners and moving on to many others species. He even spent eight years studying barnacles. While breeders had the ability to artificially control the selection process, Darwin had the insight that the forces at work in nature might produce the same effect in the wild, hence his term ‘natural selection’.

Darwin eventually arrived at the basic tenets of evolution by natural selection. (The Advancement of Science, Philip Kitcher, 1993, p. 19. I have mentioned these before but reproduce them here for completeness.)

1. The Principle of Variation: At any stage in the history of a species, there will be variation among the members of the species: different organisms belonging to the species will have different properties.

In other words, children are never identical with their parents. Within each species there is considerable diversity in properties (the larger the population, the greater the diversity) and in support of this position, Darwin took great pains to point out how hard it was to distinguish between different varieties within the same species, and between species.

2. The Principle of the Struggle for Existence: At any stage in the history of a species, more organisms are born than can survive to reproduce.

If there is an abundance of food and other resources, the population of any species would multiply exponentially, as suggested by Malthus. The fact that it doesn’t is due to limitations in these necessary elements and this is what results in only some surviving and populations reaching more or less stable values.

3. The Principle of Variation in Fitness: At any stage in the history of a species, some of the variation among members of the species is variation with respect to properties that affect the ability to survive and reproduce; some organisms have characteristics that better dispose them to survive and reproduce.

The members of a species that are more likely to survive and pass on their properties to the next generation are those that have properties that give them some survival advantage in the environment in which they find themselves. It is important to note that only some of the properties need to be advantageous for the organism to have preferential survival. Other properties may also flourish not because they have an advantage but because they are somehow linked to advantageous properties and are thus carried along. Thus some properties may simply be byproducts of selection for other properties.

4. The Strong Principle of Inheritance: Heritability is the norm; most properties of an organism are inherited by its descendents.

Most properties that we have (five fingers, four limbs, one heart, etc.) are inherited from our ancestors.

All these four things were not controversial and were not hard to accept even for religious people. What gave Darwin’s theory its uniqueness and created controversy was that from these four principles, he inferred the crucial fifth. It was this extrapolation that is the key to Darwin’s theory of natural selection.

5. The Principle of Natural Selection: Typically, the history of a species will show the modification of that species in the direction of those characteristics which better dispose their bearers to survive and reproduce; properties which dispose their bearers to survive and reproduce are likely to become more prevalent in successive generations of the species.

So natural selection will favor those organisms that, by chance mutation, have properties that give them better chances for survival, and thus these characteristics will appear in the next generation in greater abundance. And from this he inferred that as these changes accumulate, eventually new species emerge.

But it was one thing to have a theory that satisfied him. It was quite another to convince others that it was the explanation for the diversity of life. There were many obstacles he had to overcome, not the least of which was the scale of time he was asking people to envisage was much longer than they were used to, the size of the mutations that underlay the process were so small as to be mostly invisible, and there was no agreement at that time on the whole question of how characteristics were inherited and how variations occurred in species.

It was to try and meet these objections that Darwin spent the rest of his life accumulating vast amounts of evidence from all over the world. Darwin, great scientist that he was, knew that just having a good idea wasn’t enough in science, however beautiful the idea was. You had to have evidence to support it.

Next in the series: How probability ideas can lead us astray

POST SCRIPT: How can we miss you if you won’t go away?

I was looking forward to British Prime Minister Tony Blair leaving office today. I found his preening pieties, his obsequious behavior toward Bush, and his self-righteous attitude irritating in the extreme and was looking forward to not having to see that on public display. But now comes the alarming news that Bush is thinking of making him some kind of special envoy to the Middle East, so we will be forced to endure even more of his grating presence.

Maybe Bush likes having his ‘pet poodle’ (which is actually an insult to a fine and dignified breed of dogs) around but as long-time Middle East correspondent Robert Fisk points out in the British newspaper The Independent, those who think that Blair, whom he describes as “this vain, deceitful man, this proven liar, a trumped-up lawyer who has the blood of thousands of Arab men, women and children on his hands,” has any credibility at all in the Middle East are woefully mistaken.

The mixed views of candidate Ron Paul

If anyone had any doubts that the US is ruled by a single pro-war, pro-business party, recent Congressional action should dispel them. It is clear that the wheels are already being oiled for starting a war with Iran, and the Democrats are complicit in this pre-war demagoguery, just as they were before the war with Iraq, when many voted for the Iraq war authorization resolution.
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Evolution-3: Natural selection and the age of the Earth

(See part 1 and part 2.)

It is clear that many people find it hard to accept Darwin’s theory of evolution by natural selection. One reason is of course because it completely undermines the need to believe in a creator, making god superfluous when it comes to explaining the nature and diversity of life, and thus people may have a negative emotional reaction that prevents them from seeing the power of the theory. As I have discussed earlier, people are quite able to develop quite sophisticated reasons to believe what they want and reject what they dislike.
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Film reviews: Network and Matewan

Here are two more reviews of old films that are worth seeing.

Network (1976)

This film is a brutal satire on the TV news business and, sad as it is to say and even harder to believe, the kinds of attitudes it satirized in 1976 has only gotten far worse in the subsequent three decades.

Screenwriter Paddy Chayefsky uses the story of Howard Beale, a network news anchor who has a mental breakdown when he is told that he is being fired because of his low ratings, to show what really drives TV news. When Beale starts saying the truth on air about how things really work in the news world and the contempt that the people in TV have for the intelligence of their viewers, he starts getting audience attention and his ratings start going up again. He starts to pick up steam by voicing the frustration and sense of powerlessness that people feel.

The people in the entertainment division of the network see the chance to gain huge ratings by converting the news into a kind of entertainment, complete with segments involving soothsayers and the like, the whole thing showcased by Beale, now nicknamed ‘the mad prophet of the airwaves’, ranting on some topic, as can be seen in this clip, where he denounces the dangerous control that TV has on the minds of the public.

(Nowadays, nowhere is this film’s critique of how ‘news’ has become trivialized more apparent than in the ridiculous amount of coverage given to Paris Hilton. The best commentary on the media frenzy about the non-event that was her recent jailing was that given by Tommy Chong in an interview with Stephen Colbert.)
The film is immensely helped by the performances of two wonderful actors (William Holden and Peter Finch) in the twilight of their careers, aided by two other fine actors Faye Dunaway and Robert Duvall who were at their peak. Finch won an Academy Award for his performance but died before he could accept it.

Although Chayevsky a tendency has sometimes to give his characters (especially the one played by Holden) set-piece speeches on life and love and death that give the film a somewhat stagey-look, his writing is so good that he gets away with it. There are some interesting side-plots involving urban guerrilla chic and radical black activists of that time. The film shows how, in the end, everyone is corrupted by the allure of fame and money that TV exposure brings, and are willing to be manipulated by the TV executives to achieve that goal.

Network is one of those films that I saw when it first came out and is still good after all these years. It is a film that has become a cultural touchstone, with the line “I’m as mad as hell and I’m not going to take this anymore” familiar to people who may not know from where it originated.

Matewan (1987)

Matewan is another fine film by independent filmmaker John Sayles. It is based on the true story of the struggle of coal miners in the West Virginia town of Matewan to obtain better condition by forming a union, and the fierce attempts by the mine owners and their thugs and goons to prevent it. Seeing films like this makes me appreciate so much more the efforts of the early efforts at unionization, fought by workers and their families at great cost and danger to themselves, which now give us the kinds of working conditions and safety that we take for granted.

Sayles’s first film was The Return of the Secausus Seven (1980), the story of a group of high school friends who reunite for a vacation ten years after graduation. It was shot on a low budget with an unknown and almost amateur cast. The much better-known The Big Chill (1983), which has almost the same story, looks like an unacknowledged remake of Sayles’s film.

Sayles has since gone on to make more commercially successful films (you can see a list of the films he as made here) and has been able to attract better known actors along the way, with some of them, such as Chris Cooper and David Strathairn, appearing repeatedly.

Sayles epitomizes the true independent. Many filmmakers like Steven Soderbergh who began as independents went the big budget Hollywood route after they achieved commercial success. Sayles refuses to do so. Even after he has shown himself to be a critical and commercially successful filmmaker, he refuses to seek funding from the big studios because they would require him to relinquish control over the final product. He says:

I want to direct films that no one else is going to make. I know if I don’t make them, I’m never going to see them. Of course, I hope some people will want to see my movies as well, but I won’t pander to the public. I won’t try to second guess what a Hollywood studio would like to see in a low-budget film, so that they will hire me the next time around. I know I will always do better work if I do projects in which I really believe. And if I never get to direct again, I will have made some movies I can feel proud of.

Sayles is very good at capturing the mood of a time and an event, and does not shrink away from showing the politics of race and class. For him, what a film says is more important than how it looks. As he said, “I’m interested in the stuff I do being seen as widely as possible but I’m not interested enough to lie. . .[A movie] may not look the way we’d like it to look or sound the way we’d like it to sound or get seen by as many people as we’d like to have see it but at least it will say the stuff we want it to say.”

Evolution-2: The lack of evidence for perfect design

In the first post in this series, I showed with the example of a soap spray nozzle how natural design could come up with systems whose intricacy and complexity is such that it was superior to the efforts of intelligent human designers. But what about the argument that a god-like designer would be able to come up with an even better nozzle design? It is true that if we allow for the existence of such a designer, we could get the best possible design for a nozzle. The catch is that assuming that god is a perfect designer opens up a whole set of new problems, not the least of which is why if god is so powerful he would need any kind of nozzle at all and not simply create any kind of spray he/she needed.

Let me start with a limitation of natural selection. There is a well known result about any method of solving a problem that starts (like natural selection does) with some state, tries out small variations, selects the one that shows the greatest improvement over the starting point, tries out variations based on that new state, selects the best one again, and so on, which is exactly the way that natural selection works. The problem is that while you will end up with a better result than the one with which you started, it may not be the very best solution that is conceivable. Such algorithms result in finding a locally optimal solution but not a globally optimal one.

As an example, suppose you are in open ground and totally in the dark. For some reason, you need to get to the highest point in the ground, say because flooding is occurring and you know the water is rising very slowly. (The specific reasons are not important. The point is to have some kind of external pressure that drives the selection process in one direction.) You could gingerly take small steps in every direction, see which way went up the most, and move one step in that direction. Then you again take tiny steps in all directions and select the one direction that moved up most, and move to that position. And so on. By repeatedly doing this, you are guaranteed to arrive at a peak.

(This is how natural selection works, though to be a more accurate analogy, we need to start with many people at the starting point, have couples move in each direction, have only the couples that get to higher ground survive while the others drown, have those successful couples produce lots of children at that location, who then move as couples in different directions, and so on.)

The catch is that the peak you arrive at may not be the highest peak in the vicinity. If a yet higher peak were to be separated from your initial starting point by even a small dip in the ground, you would miss it using this algorithm, since it does not allow you to make a short-term disadvantageous change in anticipation of future benefits. Natural selection is not guaranteed to produce the very best or the most perfect solution or design. It instead works on a ‘just good enough for now’ basis. This means that biological systems do not necessarily make progress towards perfection even though they do become more complex over time.

Now a god-like designer would presumably be able to see all the possible solutions (even in the dark) and pick the one that is best overall and guide you to that point. But the interesting thing is that the results of nature are more consistent with the ‘just good enough for now’ strategy of natural selection than that of a perfect designer. After all, we know that while nature’s designs (by which I mean designs arrived at by natural selection) are marvelously adapted and successful for many things, they are by no means perfect.

As Sean B. Carroll says in his book The Making of the Fittest (2006) which examines the DNA evidence for natural selection:

Modern species are not better equipped than their ancestors, they are mostly just different. They have often gained some coding information in their DNA and, as I have shown throughout this chapter, they have often lost some, or even many, genes and capabilities along the way.

The fossilization and loss of genes are powerful arguments against notions of “design” or intent in the making of species. In the evolution of the leprosy bacterium, for example, we don’t see evidence that this pathogen was designed. Rather, we see that the organism is a stripped-down version of a mycobacterium, which still carries around over a thousand useless, broken genes that are vestiges of its ancestry. Similarly, we carry around the genetic vestiges of an olfactory system that was once much more acute than what we have today.

The patterns of gain and loss seen species’ DNA are exactly what we should expect if natural selection acts only in the present, and not as an engineer or designer would. Natural selection cannot preserve what is not being used and it cannot plan for the future. (p. 136)

The very fact that it is estimated that over 99% of all the species that ever existed are now extinct is powerful evidence against perfect creation. The only way out of this for the religious believer is to think that god, although perfect, is somehow holding back and deliberately creating imperfections and thus making it merely look like something like natural selection is at work. Or god does not interfere at all, ever in the natural selection process once it began way back at the beginning of life. Or is simply careless and produces sloppy designs.

Darwin himself, based on his careful study of plants and animals, found it hard to believe in the idea of an intelligent designer. His biographer David Quammen in the book The Reluctant Mr. Darwin (2006, p. 120) highlights the kinds of questions that troubled Darwin, and which he expressed in letters to the Harvard botanist Asa Gray, who believed in the idea of special creation of humans.

I cannot see, as plainly as others do, evidence of design & beneficence on all sides of us. There seems to me too much misery in the world.
. . .
Why would a benevolent God design ichneumon wasps, for instance, with the habit of laying eggs inside living caterpillars, so that the wasp larvae hatch and devour their hosts from inside out? Why would such a God design cats that torture mice for amusement? Why would a child be born with brain damage, facing a life of idiocy?
. . .
An innocent & good man stands under [a] tree & is killed by [a] flash of lightning. Do you believe (& I really shd like to hear) that God designedly killed this man? Many or most persons do believe this; I can’t and don’t.

The question of pointless suffering and loss were not hypothetical issues for Darwin. He had been devastated when his own beloved daughter Annie had, at the age of ten, died after a long and mysterious and undiagnosed wasting illness. Darwin seemed to feel that such things were incompatible with a benevolent deity. As Quammen writes, “Any god who controlled events on Earth closely enough to preordain such an occurrence – or to permit it, if permission was necessary – wasn’t one that Darwin could take seriously.”

Darwin’s theory of evolution by natural selection, although not aimed at doing so, ultimately provided the basis on which belief in a designer god, and thus god itself, could be abandoned.

Film reviews: Hearts and Minds and Medium Cool

Film reviews are usually about films that have been newly released. Since I am almost never the first to see any film, my reviews deal with very old but good or interesting films that people may have not seen the first time around but can do so now, thanks to the easy availability tapes and DVDs. I see these reviews as pointing out films to those who may not know what they are missing.

Here are reviews of two old films that I saw recently that dealt with the time during the Vietnam war.
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Evolution-1: The power of natural selection

We are rapidly approaching 2009, a year that marks a major scientific milestone that is going to be commemorated worldwide. It is both the 150th anniversary of the publication of the landmark book On the Origin of Species that outlined the theory of evolution by natural selection, and the 200th anniversary of the birth of its author Charles Darwin.

Darwin’s theory represents arguably one of the most, if not the most, profound scientific advances of all time, ranking well up with those scientific revolutions associated with the names of Copernicus, Newton, and Einstein. And yet it is widely misunderstood, or more appropriately, under-understood because most discussions of it remain on too high a level of generality, enabling critics to make statements about the theory that are not valid but yet seem plausible.

In order to create a better awareness of what the theory involves, today I will begin an occasional series of posts that looks at the details of the theory, including the mathematics that underlies it and which was developed later by people like J. B. S. Haldane, Sewall Wright, and R. A. Fisher.

One of the most common misconceptions about evolution by natural selection is that it works purely by chance. After erroneously assuming that notion, people then look around them, see the wonderful complexity of nature, and conclude that this simply could not have occurred by chance and that therefore this points to the existence of a designer who must be god. This is exactly the explicit argument of intelligent design creationists, but also the implicit argument of some people who want to somehow find evidence for the necessity of god’s existence.

It seems as if no amount of reiteration (by those who have studied the theory of evolution) that this basic assumption of chance is not true, seems to have any effect. I recently had a correspondence with someone who, despite my repeatedly pointing out that chance was not the sole driver of natural selection, kept saying things like “How can you think all this came about by chance?”

Now chance does play a role in the way that genetic changes occur, externally from the occurrence of mutations due to things like ultraviolet radiation, and internally in the way that genetic shuffling occurs in the copying of the genetic information during reproduction. You cannot be sure, for example, what genetic features you will inherit from your mother and what from your father. But these chance variations are then acted upon by selection forces that are the very opposite of chance in that they pick out only those varieties that are beneficial for future propagation. This is a highly directed process that acts without an intelligent director and it is these selection forces that are behind the complexity of the systems that have evolved.

In response to the “evolution is just chance and is very unlikely to produce complexity” argument, those who understand the theory of evolution sometimes argue in its defense that the theory is just as good at producing complex things as any conscious designer. But such people are really selling the theory short. In actual fact, the theory of evolution by natural selection produces results that are often much better than those produced by conscious design.

A wonderful example that illustrates this point is given by biologist Steve Jones, as recounted in his book Almost Like a Whale: The Origin of Species Updated (1999) (Chapter IV, Natural Selection). (Thanks to Heidi Cool for alerting me to the podcast of a talk by Jones which is where I first heard this story.)

I once worked for a year or so, for what seemed good reasons at the time, as a fitter’s mate in a soap factory on the Wirral Peninsula, Liverpool’s Left Bank. It was a formative episode, and was also, by chance, my first exposure to the theory of evolution.

To make soap powder, a liquid is blown through a nozzle. As it streams out, the pressure drops and a cloud of particles forms. These fall into a tank and after some clandestine coloration and perfumery are packaged and sold. In my day, thirty years ago, the spray came through a simple pipe that narrowed from one end to the other. It did its job quite well, but had problems with changes in the size of the grains, liquid spilling through or − worst of all − blockages in the tube.

Those problems have been solved. The success is in the nozzle. What used to be a simple pipe has become an intricate duct, longer than before, with many constrictions and chambers. The liquid follows a complex path before it sprays from the hole. Each type of powder has its own nozzle design, which does the job with great efficiency.

What caused such progress? Soap companies hire plenty of scientists, who have long studied what happens when a liquid sprays out to become a powder. The problem is too hard to allow even the finest engineers to do what enjoy the most, to explore the question with mathematics and design the best solution. Because that failed, they tried another approach. It was the key to evolution, design without a designer: the preservation of favourable variations and the rejection of those injurious. It was, in other words, natural selection.

The engineers used the idea that moulds life itself: descent with modification. Take a nozzle that works quite well and make copies, each changed at random. Test them for how well they make powder. Then, impose a struggle for existence by insisting that not all can survive. Many of the altered devices are no better (or worse) than the parental form. They are discarded, but the few able to do a superior job are allowed to reproduce and are copied − but again not perfectly. As generations pass there emerges, as if by magic, a new and efficient pipe of complex and unexpected shape.
Natural selection is a machine that makes almost impossible things.

In other words, by mindlessly applying an algorithm based on the principle of natural selection, they were able to come up with a complex design for a superior spray nozzle that was inconceivable to the scientists trying to design one using engineering and science principles.

Believers in a god-like designer might argue that what natural selection did here was outperform mere mortal designers and that god, being a perfect designer, would be able to come up with a better design. But that argument doesn’t work that well, either, as I will discuss in the next posting in this series.

Guest post by Corbin Covault

My two posts on Taking offense and Taking offense (revisited) generated a lively discussion in the comments. One of the responses covered many of the issues raised by those who disagreed with some or all of my remarks and I felt that it should reach a wider readership so I asked the author to write it as a guest post. While it is a little longer than my own posts, I think readers will find that it provides an interesting perspective.

So what follows is Corbin’s guest post:

Thank you for your very thoughtful response to comments by myself and others regarding your post on taking offense. Indeed you tend to present very thoughtful remarks on your blog which is why I like to read it, and this most recent post is one of your most thoughtful. Your point on the tendency of conflation between plausibility and worthiness is particularly well taken.

Having said this and having reflected further on the issue, I would still say that you should not have been surprised to learn that some religious believers would find your comparison of belief in god to belief in the Easter Bunny offensive. But I should emphasize here at the start that I did not mean to imply in my previous comment that I myself found the comparison between god and the Easter bunny or whatever offensive. And even if I did, I probably not have “taken offense” at what was said.

An aside: I suppose it’s a level of degree: I mentioned before that I find many of Ann Coulter’s assertions offensive, but I do not “take offense” as she is so uniformly outrageous that it seems actively responding to what she says might serve no purpose. I also have number of friends and colleagues who by temperament may tend to say or do “offensive” things but since I otherwise value or respect the relationships for various reasons, its better to simply ignore the offense. In contrast, I recently found myself “taking offense” at some of our local Democratic congresspersons who failed to vote no on the war funding bill. In this case my offense took the form of phone calls, email and letters to the editor making known my unhappiness that they voted in apparent opposition to their stated commitments to end the war as soon as possible.

Anyway, I am saying that since you brought the topic of taking offense up, it seems quite natural to me that some people would find your comparison between god and childhood fictitious characters offensive. And as I said, I found Kathy’s points rather compelling for the reasons I stated earlier.

Upon further reflection, I realize part of the issue has to do with what I might call my natural tendency to try to put myself in the “other person’s shoes” on both sides of any discussion. If one side indicates that something expressed is “offensive” then this might be an indication that the other side appears not to have sufficient empathy for the alternate point of view.

I realize that an “apparent lack of empathy” for an opposing viewpoint is hardly a basis for evaluating the validity of a rational argument. But from a practical point of view in the context of persuasion and possible consensus building, it seems that some of the most effective discussions between opposing viewpoints result when a real effort is made by both sides to see the situation from an honest point of view of the other side. Of course the strength of arguments comes into the discussion as well, but I will say, based on my experience, that if there is not at least some level of willingness to “honor the viewpoint” of the other side, then all of the arguments in the world, no matter how rational, will fall on deaf ears. And if one side or the other “takes offense” then perhaps — maybe — this might be an indication that someone, somewhere is not really living up to this ideal of trying to be empathetic with the other side at some level.

Of course, I am not suggesting that trying to “avoid offense” is worthwhile in every scenario. If one is attempting to argue against what is perceived as a very dangerous idea, or if one is trying to counter an argument made by someone who at the onset demonstrates a propensity for demonizing those with opposing views then perhaps taking the empathetic tack might not get too far. As you indicated, perhaps there is not much value in worrying too much about whether Dick Cheney is offended by something. But I will contend that if one’s purpose is to engage in a dialog with individuals or groups who have an opposing point of view, but with whom you otherwise might respect and are trying to persuade to your own point of view, then raising arguments that might be construed as offensive — even if such an offense might be deemed irrational — might not be the best tactic, practically speaking.

I also recognize that there is a difference between the “public realm” of discourse and debate (which seems to be more “rough and tumble”) and the private or pseudo-private realm within (for example) families and organizations where a need for empathy might be much more motivated between people who have to be in close proximity to each other in some sense.

I suppose a “blog” lives mostly in the “public sphere” sort of….

Yes, I agree very strongly with your general point that it is not “fair” for people with religious ideas to expect to be insulated from any kind of criticism (rhetorical devices as you put it) even if the device is relatively harsh. I agree that any set of ideas, in a free and pluralistic society, is fair game for public scrutiny.

But I could also argue that making arguments with harsh rhetorical devices might not always be the best way to make arguments in any sphere of discourse. I can think of two or three columnists, for example, that actively promote political views that I substantially agree with but who do so with such venom for any opposing view that I am embarrassed. Perhaps one might excuse such a confrontational approach in the sciences, since ultimately any particular viewpoint will be resolved not by the emotional strength of an argument but by experimental verification. But in the political (and religious) arenas, there is no experimentalist to resolve the argument about competing theories.

It’s not obvious to me that the way to find the best ideas in any given arena is always to subject them to withering rhetorical attacks to test their survivability. And one could argue that the use of harsh rhetorical devices might be as unhelpful for moving forward a rational discussion of the issues in the political and policy arenas as it may be becoming within the religious spheres. This is not to say that there is not a time and a place for the expression of objection, protest and complaint within a political arena, for example. But it seems to me that such activity all by itself is not the equivalent of making rational arguments. And it is my belief that if the rationale for an argument is sound, it should not depend so sensitively on a need to be expressed in the context of harsher rhetorical devices. And it might even be the case that the argument can be made more effectively if it is make empathetically. It’s an issue of persuasion.

As an example in the political arena, one might argue that the Greensboro sit-ins did much more to persuade white Americans of the validity of civil rights demands than did any number of protest marches. So I am not saying that atheists do not have the right to make harsh public criticisms of religion. They certainly enjoy that right and religious people do not really have any basis to ask for special protection from such criticism. I am just saying that using harsh rhetorical devices might not always be the best idea if you want people to listen thoughtfully to what you are saying. So yes, as you say, that ship has sailed, but perhaps not everyone ought to hop on it.

Indeed, I might suggest that the fair complaint about of some of the writings of the “new atheists” is not so much that the arguments are “disrespectful” but that they are sometimes rather non-empathetic to the opposing point of view. Some of the writing seems to be developed with the aim of simply tearing down a viewpoint rather than persuading people to change their minds. Again, this has nothing to do with the rationality or validity of the argument, but if the argument comes across in a certain way it may not “convert” fence-sitters or others. Indeed if the tone is perceived as too strident then you risk turning people off to your argument, logical or not.

For example, I personally cannot read much of what Sam Harris writes….not because his arguments are unsound (although there are several arguments he makes that I do not agree with) but because much of his writing is so uniformly unsympathetic to any opposing view. For example, in your quote of Sam Harris where he says: “[Atheism] is simply an admission of the obvious…” This comes across as rather arrogant and to just this extent it’s sort of offensive — or at least irritating. “Obvious”? Obvious to whom? To many people the word obvious implies something that “anyone but a simpleton”, anyone who has any rational ability at all, would readily agree to. In fact, by such a definition, atheism appears to be rather non-obvious. I know this is not the intended meaning. I know that Harris really means “obvious in the context of following the rational implication of adopting a purely scientific perspective on all things.” But he doesn’t put it that way, exactly. Instead he gives the impression of impatience and self-righteousness. I suspect that this particular wording of his argument here would only be appealing to someone who already shares this point of view.

I can think of one other example of this kind of thing. Some years ago I was involved in a class that dealt with the issue of scientifically assessing pseudo-scientific claims. It was a class for non-science majors, and one of the books on the reading list was The Demon-Haunted World: Science as a Candle in the Darkness by Carl Sagan. From my point of view this was an excellent book for this course that went right to the heart of several keys issues that I hoped the students would be addressing in the class. However, I was surprised by an outpouring of rather strong negative feedback about the book that I was getting from a large number of students in the class. Students felt that the writing was “arrogant”, “condescending” and uncompelling — “annoying to read” — this from students who were otherwise apparently quite open in a general way to looking and considering ideas about how to scientifically approach pseudo-scientific claims.

The problem was not that Sagan’s message was wrong or unsound — the problem was that it did not reach students where they were at. It turned students off. The point here is that in this context, at least, even to the extent that the scientific message was presented with what I thought was a reasonable tone, students turned away from what they perceived to be a “harsh argument” even when ultimately they found similar arguments quite compelling when presented in a different context.

Okay now finally, I would like to articulate one last reflection related to the atheism arguments you have made. Specifically, it seems like your whole case for atheism rests on the central premise that one should “take a scientific approach to every aspect of life.” You contend that atheism is not in-and-of-itself a philosophy, but I do not understand how a decision to “take a scientific approach to every aspect of life” is not itself a “philosophy”. Maybe I am misunderstanding your use of the word.

Indeed, if I narrow the issue further, it still seems like the application of science is a “philosophy”. If you say something as restricted even as “the best way to understand the physical universe is to apply the scientific approach” isn’t this a “philosophy”? Don’t we even call our experts “doctors of philosophy”? I will agree that it is a mighty powerful and effective philosophy but I do not see how it is not a philosophy. I do not see how science itself can be justified “scientifically”. We apply science to the physical world and we discover “it works”. Are you contending that science can be used to self-justify itself?

Likewise, when you make the argument that the “scientific approach should be applied to every aspect of life” are you not extrapolating at some level? I will concede that if one grants that such an approach should be taken, then what I will call a “strong atheism” is the logical rational conclusion. But I am not sure that rationality itself compels such an extrapolation. And while you might argue that the reason religious believers resist such an extrapolation is because they are extremely motivated to defend their beliefs, there have been and continue to be several prominent atheists who have also argued that it is not scientifically justified — or particular helpful for the cause of science — for atheistic scientists to make such an extrapolations. For example such an ardent defender of the scientific point of view as Lawrence Krauss has argued that science itself should not be used to dispute untestable religious claims. You may not agree with his conclusions but you also cannot attribute his opinion to a strong desire to defend his personal religious beliefs.

To my mind part of the issue is to what end is such an extrapolation being applied. What is the aim of extrapolating the very successful approach of science to arenas where science has not so clearly applied itself as successfully? What is the desired outcome?

It seems to me that the purpose of the application of science to the physical universe is the understanding of the underlying nature of physical reality — that is to determine what is and is not objectively true.

But I think the case can be made that there are topics and issues where we might be properly motivated by considerations that have nothing specifically to do with whether something is objectively true or not. There are issues worth contemplating that are not related to anything really existing or not. I suspect this is the case for many people with regards to religious issues. This gets back to the “plausibility” vs. “worthiness” issue. I suspect that for some religious people — especially those that might fall more into the “liberal” end of the spectrum — the issue of whether there is evidence for god’s existence has much less relevance than the issue of the value that the religious experience provides.

Indeed, you have mentioned and promised to address the issue of the “net good vs. evil” issue of religion in the world, and I think this is quite a tricky knot to tackle, but for many people, I suspect further that the motivation to adopt a religious perspective has less to do with the net world social value of religion and much more to do with the perceived value of that perspective to the individual, and this value is the central issue in making the decision to adopt the religious perspective. In other words it’s a personal choice that is based on the attractiveness of the experience rather than on whether some particular claims are being made and if they are true or not.

I would also argue that this kind of value can be defended, even if the defense is not based on a “rational argument” as to whether some claim is true or not. As you have admitted before, we all have “irrational” viewpoints on a number of things. But I think that perhaps one can argue that this irrationality does not automatically reduce the value of the viewpoint. If one assumes that some perspective provides value for the individual, then this can be a “reasonable” basis for that individual deciding to adopting the perspective, even if the perspective cannot be judged to be “rational”.

For example, last night I went to a baseball game. I had a great time (despite the fact that the home team lost) and I would go again. But I cannot see any way to justify my attendance at the game from a scientific point of view. Why did I go? Because it was appealing to go. Why did I cheer for the home team? Certainly not because I have some illusion that they are objectively more deserving of my support and praise relative to their opponents. Rather, I cheered the home team because the ritual of sport is constructed this way and because by investing myself in the outcome I become more engaged in the game and find it more rewarding. When the game ends, and the home team loses, however, I am quite content to put aside the ritual and recognize that the value of ritual is simply the emotional reward of the game itself. I do not carry my investment in the home team around with me from day-to-day. I am not a “sports fundamentalist”.

Similarly, suppose a student is considering a life in pursuit of a career as a concert musician. I am thinking that such a decision would be difficult to defend on the basis of a scientific argument. The basis for making such a decision is not whether or not something objectively exists (except perhaps, musical ability). The issue is whether the pursuit of such a career is seen as worthwhile.

It’s further worth remarking that just because neither baseball nor music can be justified scientifically does not mean that either of these enterprises is intellectually valueless.

Nor are these activities free to operate in a way that contradicts or ignores the constraints imposed by the laws of science. Physics governs baseballs and oboes. But physics does not define the home-run. Physics does not define an “impressive” concerto. People do this.

In the same way, then, I think, that there can be particular religious perspectives (liberal ones, I would think) that can make a case for themselves for particular individuals based not on assertions of belief regarding the existence of god, but on the value that these religious perspectives can provide — a value that is more comparable to the value of a game of baseball or the value of a life committed to musical excellence than it is to the value of determining the age of a rock or the charge on a quark. In my opinion, if such a religious perspective is constructed in a manner such that its claims are not inconsistent with the demonstrated laws of science then it may be defended as “worthy” in this context. The example I mentioned before, where the traditions are interpreted metaphorically, not literally, and where the emphasis in on the artistic interpretation of the narrative — and not on any objective claims of belief about the physical or meta-physical nature of god — seems like one example of such an acceptable construct.

Finally, I would note that with such a liberal religious perspective, there is no claim on any kind of “literal truth”. Such a viewpoint rather explicitly recognizes that the narratives from one tradition may be more or less attractive and worthwhile, varying from person-to-person and from culture-to-culture. In other words, the liberal tradition embraces an ecumenical perspective where a diversity of religious viewpoints and traditions by others are accepted and even celebrated.