The Enlightened Caveman

You Animal You
February 2, 2005, 4:34 pm
Filed under: Culture and Society, Enlightened Caveman Concept, Science

Original Post (with comments)
A couple of recent posts have generated some lively discussions, and some of them have led to the nature versus nurture debate. I have been arguing that we come with many of our basic emotions pre-wired, and that it is only the relatively new emergence of malleable cognitive faculties that gives us the chance to change the outcome of situations that would otherwise go down as instinctive responses to external stimuli. Basically, the complexities of cognition and consciousness provide us with free will. Some, however, do not agree. They believe that the hard-wired parts of our minds are limited to the autonomic stuff and the basic survival skills (fight or flight, etc.). They think that the only way I can be right is if humans are robots, robots that were designed. I’ve made my case in comments and will probably attempt to summarize once the dust settles, but I think there’s some value in introducing some basic cognitive science into the picture. What follows is taken almost directly from Chapter 3 of my book.

Contrary to what many people like to believe, no need to believe, humans are not cosmically special. We are animals, not uber-rulers of a vast universe. Yes, we are sophisticated and capable of staggering feats of intelligence, but we are also consistently guilty of acts of passion that mirror the instinctive exploits of our animal cousins. What can we say? It’s in our genes. We all have the same basic genetic framework. The same four letter DNA alphabet (A, T, G, and C) serves as the underlying scaffold for all life on earth. Strands of DNA form genes. Throughout the history of life on this planet, genes have given rise to new organisms that were incrementally different from the ones that came before. However, new organisms were not created from scratch every time. Their designs were built upon designs that have worked well all along. This is why it makes sense that we share 98% of our DNA with chimpanzees, but only 90% with mice. This notion of conservation of design is starkly evident when it comes to the design of the human mind.

The vertebrate brain is divided into three major divisions: the hindbrain, midbrain, and forebrain. It turns out that the structure and function of the hindbrain and midbrain in humans are very similar to what is seen in reptiles, birds, and other mammals. All vertebrates have basically the same organization in the spinal cord, brain stem, thalamus, and cerebellum. That goes for rats, lizards, chimps, and humans. To go even further, we know that the same neurochemicals found in the human brain are also found in the nervous systems of leeches and worms, as well as reptiles, birds, and other mammals. Of course, this is not to say that we have the same minds as other animals. Humans are certainly endowed with mental structures and capabilities that far exceed those of any other animals on our planet. The point, however, is that the aspects we share with other animals are playing a leading role in our everyday lives, whether we know it or not. A light exploration of the architecture of the human mind will give us a feel for this.

The fact that we share our emotional infrastructure with other animals has a profound implication on how we experience life and on our search for truth. Consider the following diagram.
Brain Diagram

It depicts the pathway from an emotional stimulus to a bodily response in the brain. The first thing that happens is the emotional stimulus (say spotting a bear when you’re walking in the woods) sends a signal to the thalamus. The thalamus sends the signal to both the amygdala and the cerebral cortex. The amygdala (a brain structure known to be critical in the execution of basic emotional behavior) is responsible for issuing the response as quickly as possible to prepare you for action. The thalamus to amygdala loop constitutes what we’ll call the emotional pathway. The response it issues manifests itself not only in the immediate body response (such as elevating your heart, causing you to freeze, and preparing your muscles to act), but also in a signal to the cerebral cortex. The cerebral cortex has the luxury of taking its time to receive the signals both from the thalamus and from the amygdala. It also sends signals back down to the amygdala to be processed along with incoming information from the thalamus. So, the conscious emotional experience is separate and comes after the emotional response. The emotional response is what we share with all vertebrates. The emotional experience is reserved for those of us with consciousness. The jury is out as to exactly where that line is drawn, and I won’t dare hazard a guess. But I’d like to believe my dog is conscious. In any case, there are some points to be made about this arrangement between emotions and cognition.

In terms of the brain, there is a “low road” and “high road” when it comes to mentally processing an external stimulus. The low road is the evolutionarily old route. It corresponds to the pathway from the stimulus to the thalamus to the amygdala to the bodily response. This is the basic flow of what we can think of as emotional programs that take place in what is known as the emotional unconscious. It was designed by evolution to produce survival-enhancing responses to stimuli in the real world. This is really the point of the emotions we share with other animals – they are our rapid-response system. The high road, on the other hand, is the evolutionary new kid on the block. It corresponds to the pathway from the emotional stimulus to the thalamus to the cerebral cortex to the amygdala (and back to the cerebral cortex in a loop) to the bodily response. The cerebral cortex is, in a sense, where the cognitive processing happens. While the stimulus is eliciting a response on the “low road,” the cerebral cortex is assimilating both the stimulus and the emotional response into something that can be considered in a larger context. There are two aspects of this arrangement that have implications on our everyday lives.

The first is the notion that emotional processing inhibits cognition. Look back at the diagram and notice how the brain’s cognitive and emotional equipment are connected to each other. As crude as it is (I hear publishers have editors for this kind of thing), the arrangement is deliberate. The emotional low road is connected more closely to the nervous system, and therefore to the environment, than the cognitive high road. This is because, in evolutionary terms, it is much older. It is the part of the brain that we share with other mammals. In a way, our emotions are our brain’s first line of defense. The cognitive loop is “above” the emotional loop in the sense that all stimuli pass through the emotions en route to the cerebral cortex. The thalamus to amygdala loop, therefore, gets first right of refusal in terms of mounting a response to any given stimulus. It gets to decide whether and how to react to a stimulus before the high road is ever involved. This is important because, when the emotions take charge, there seems to be little room for cognition. It’s that simple. And there are plenty of examples in everyday life to prove it.

Ask almost any first time mother of an infant this question. When your baby cries, how easy it for you to think clearly? My straw poll of some well-educated young mothers yielded a pretty much unanimous response, “When my baby cries, I become completely stupid.” They went on to explain that the sound of their babies’ crying brought out feelings of anguish to fix the situation. Of course, as the children get older, this effect diminishes. However, the anguish is perfectly understandable. Some of the most basic emotional functions exist to ensure the wellbeing of offspring. They most directly serve the most gigantic of biological imperatives – the perpetuation of genes. It is, therefore, no surprise that the sound of one’s own baby’s crying elicits a very strong emotional response. (This was originally written before my child was born. I can now personally attest to this.) What is surprising, however, is how much our emotions are involved in our thought processes.

The second implication of the brain’s organization has to do with the cognition versus emotion question. The fact that all cognitive processing happens after emotional processing means that we can’t really be sure about the state of our processing system for any given stimulus (or situation). We can’t be sure how much of the processing that is going on is emotional versus cognitive. In other words, how much of how we are evaluating the world and responding to it is because of what we’re thinking versus what we’re feeling? As much as we would all like to say that we can usually answer that question accurately, the fact is that we really can’t. The odds are against us – for two reasons.

For one thing, emotional processing happens much faster than cognitive processing. Consider the fact that emotions evolved to deal with life and death situations. They facilitate split-second responses when necessary. Cognitive processes, however, are in no hurry. If something is important enough for you to need to respond almost automatically, you can bet there is a basic emotion mediating it. So, emotions are involved first, and they work fast. In the real world, this means that by the time we get around to thinking about something, there’s no telling how much emotional processing has occurred. We can all recall situations where we have reacted emotionally, but denied it vehemently, only to come to our senses and apologize later.

The odds are also against us because of the sheer magnitude of tasks handled by emotions versus those handled by cognition. The brain’s cognitive faculties are evolutionarily new, and they have been built on top of the ancestral emotional infrastructure we share with other animals. We are capable of handling tasks, such as finding food and shelter and responding to threats, with our emotions entirely. Whether we like it or not, the fact is that our animalistic emotions are involved in our daily lives a lot more than we think they are. They’re always on duty; that’s how the brain is wired.

So what does all this have to do with the nature versus nurture argument? It establishes the scientific basis for the idea that what we observe in nature (the phenotype) is the result of a combination of both forces – genes and the environment. More importantly, put this together with the ideas that we share much of our emotional infrastructure with animals and that other animals (primates, big cats, elephants, etc.) have basic emotions that lead to seeking status, anger, jealousy, and so on, but do not have our cognitive faculties, and you can reasonably conclude that a big part of our emotional repertoire is hard-wired. This is not to say that we are doomed to a predetermined existence. The diagram depicted shows quite clearly how the cognitive loop feeds back into the emotional loop, which means that even the most genetically controlled systems can be cognitively manipulated. That really is the scientific basis for the notion of enlightening the caveman in all of us. Am I getting through to you dualists out there?

Footnotes –
1. Some of the info on the wiring of the brain comes from Joseph LeDoux’s The Emotional Brain: The Mysterious Underpinnings of Emotional Life (Touchstone, 1996).
2. Aspects of the discussion on the evolutionary origins of emotion come from Descartes’ Error : Emotion, Reason, and the Human Brain by Antonio Damasio (Avon Books, 1994).

Evolution versus Creationism – Part 3 – Intelligent Design
January 18, 2005, 4:27 pm
Filed under: Science

Original Post (with comments)
(Warning – this is longer than usual. What’d you think – enlightenment is free?)
How do you get from primordial soup to living cell? That’s it. That’s the kryptonite in the creationist’s napsack. But that seems to be where it stays. They rarely (if ever) actually pull it out and examine it. How many times I have heard, “Ah, but intelligent design disproves everything you’re saying.” When I try to respond, deaf ears. The answer is somewhat complicated, so I somewhat understand, but it somewhat irks me that many creationists aren’t willing to fully examine what they believe, especially given how vehemently they believe them. This I also understand…somewhat.

They assume the Kryptonite works because it was handed to them by someone in whom they have implicit trust. If they put it to the test, this, the last hope for an argument that has been all but decimated in every debate it has entered, what happens if it fails? What happens if the evolutionary scientist is not weakened by the moment? What happens if the non-believer walks up, grabs the rock, crushes it into a fine powder, and sniffs some of it up his nose, and lives?! These are serious questions for some. Not me.

One thing I like about believing as I do is that I really have nothing invested in my beliefs, with the exception of my admittedly irrational belief in rationality as a superior method of thinking. But beyond that, I could change my mind about anything. Sure, it might be hard to get used to something new, but I’d be OK. All I need is for an assertion to meet my evidentiary requirements, then I’m the first to start exploring the logical consequences of it on my life. Creationists, however, do not enjoy such luxuries. Their belief in God’s creation of the world is the capstone on the arch of their religious faith. If it falls, the arch falls, and life as they know it changes forever. As I am the type to rip off the band-aid all at once, to the truly open-minded, I say get on with it. So let’s pull out the Kryptonite and take a look.

Here’s what’s about to happen, and it may not be pretty. I’m going to put forward a theory for how you get from non-living chemicals floating around in a liquid to a living cell. It all comes down to chemistry and the theory of self-organization, which is most eloquently articulated by Stu Kauffman in, At Home In The Universe. (You simply cannot consider yourself a scientist without knowing what’s inside this book.) I will start by drawing attention to the fact that something this ostensibly miraculous is actually not so uncommon in nature – we’ll look at phase transitions. Then, we’ll look at how connections between entities can become so complex that the entity itself eventually becomes something entirely different (via, you guessed it, a phase transition). I’ll then bring these two ideas together by talking about a chemical reaction network and how you to get to catalytic closure. Finally, we’ll use some back of the envelope stats to conclude that life from chemicals in a soup is not only possible; it’s probable. So consider yourself warned – serious scientifigeekification ahead.

Phase Transitions
The idea that something seemingly random can suddenly transform into something orderly may seem strange. In the world of science, these transformations are called phase transitions. The easiest example is ice. The arrangement of the molecules in liquid water is pretty much random in the sense that the nature of water is not dependent upon the specific arrangement of water molecules. But suddenly, when the temperature of the water reaches 0 degrees Celsius, the water molecules assemble themselves into the orderly substance we call ice. If you look at ice molecules under a microscope, they are crystallized in a stacked arrangement – an orderly arrangement. Ice is, in fact, defined by the arrangement of the constituent molecules as much as it is by the temperature. The phase transition in this case is the change in the physical state from liquid to solid, which corresponds to a change from disorder to order.

The point of this is to suggest that the emergence of complex life was just a phase transition, where a teeming soup of replicating molecules transformed into a cornucopia of living diversity. It’s really about connections. The following toy problem illustrates what I mean.

Buttons and Thread
Imagine throwing 1000 buttons onto a hardwood floor. Now randomly pick two buttons and connect them with a string of thread, and put them back down. Keep doing this. Sometimes you’ll pick up two buttons you haven’t picked up before. Sometimes, one or the other will already have a thread tied to it. No matter, you just keep connecting buttons. Over time, you’ll find that when you pick up some buttons, they are interconnected with several others. This is an example of a random graph. We’ll call these interconnected clusters webs. If you keep glancing at the whole floor as you connect pairs of buttons, you’ll start to see that more and more webs are emerging. You’ll start to see “islands” of buttons with nothing connected to them, bordered in all directions by webs of varying sizes. If you keep going, you’ll find that webs begin to become connected to other webs, resulting in larger and larger webs. You’ll also find that fewer and fewer islands remain. Eventually, the whole thing will be connected; it will become one big web. But it doesn’t happen steadily.

This random graph undergoes the equivalent of a phase transition when the ratio of buttons to threads reaches 0.5. So you can actually predict when the giant web will emerge! When there are 500 threads on the floor, something happens. Below 0.5, all you have is random assemblage of webs and islands – and the largest web is pretty small (a maximum of say 100 buttons). But as you approach 0.5, the webs get larger and begin to interconnect but there are still quite a few of them. But as the 0.5 mark is passed, whamo, the majority of the webs become interconnected, in one giant web. And it doesn’t matter how many buttons you use. If you throw 10,000 on the ground, as soon as there are 5000 threads, you can be sure that there will be a giant web. This is a classic example of a phase transition.

The key thing to take away from this is the idea that a phase transition can almost instantaneously change the face of things. Below 0.5, the random graph above is nothing more than a bunch of buttons and threads random connected and strewn about. Above 0.5, you quickly have a makeshift fishing net! Think about that. If you found this button and thread net hanging in your garage, would you think of it as a net or as a collection of buttons and threads? This is abstraction at its finest, and it happens via phase transitions. So what, right? Why should we believe they play a role in the origin of life explanations? Well let’s try a random graph with chemicals.

Reaction Networks
Considering how the random graph underwent a phase transition, let’s jump from talking about abstract non-living systems to talking about abstract living systems. A metabolic (or chemical) reaction graph is a graph with chemicals represented as circles, reactions represented as squares, lines indicating the reactions between chemicals, and arrows pointing to the products of chemical reactions. Here’s an example…

They come in handy when you want to visually represent all of the reactions that take place between a certain set of molecules. A reaction graph (or reaction network) is a good way to show what’s going on within a chemical system. For simplicity, we’ll look at an abstract reaction graph. Instead of using real chemicals and concerning ourselves with the specific details of reactions, this reaction graph will use generic chemicals and some simple kinds of reactions.

In chemistry, reactions are really nothing more than molecules breaking apart and mixing together to form new molecules or energy or both. Imagine chemical A and chemical B. You can turn chemical A into chemical B, and vice versa. These are one substrate, one product reactions. You can also combine A and B to get AB, and you can cleave AB to form A and B. Simple, you’re now an expert at chemistry. From there, you just add more chemicals and do more of the same kind of thing.
For example, look some more reactions you can get from As and Bs:
AB + A = AA + B
AB + A = ABA
AB + A = A + BA
I could go on and on showing the endless ways these chemicals could react to produce new chemicals. But that is not my purpose. The relevance of the reaction graph is that it works a lot like the button and thread network. Basically, you can think of the buttons as chemicals and the reactions as threads. Here’s what really matters: A network of chemicals can emerge from a random soup of chemicals simply by tuning the ratio of chemicals to reactions.

Instead of throwing buttons on the floor, let’s throw a bunch of generic chemicals into a beaker. If you’re dumb enough to try this, please place your computer next to the beaker so that there is a high likelihood that it will be destroyed if something goes wrong. I’d hate to get sued. Anyhow, for any set of chemicals, a chemist could predict what reactions would take place. The laws of chemistry dictate what the reaction graph will look like. Not too exciting really. But what happens when you add more chemicals to the mixture? You get a whole bunch more reactions. Things start picking up a bit. Thinking in terms of As and Bs, this makes sense. It’s easy to grasp that mixing AA and BB will have more possible reactions than mixing A and B. There are only three possible reactions when mixing A and B:

A can become B
B can become A
A and B can become AB
That’s about it. But look at AA and BB.
AA and BB can become A and ABB
AA and BB can become AAB and B
AA and BB can become AB and AB
AA and BB can become A and AB and B
AA and BB can become AABB
AA and BB can become A and A and B and B

It turns out that as the molecules get bigger, as you add Cs, Ds, and so on, the number of possible reactions increases exponentially. This is not only because of the reactions that can proceed between the initial chemicals. The products of those reactions then become the substrates for new reactions, thereby further increasing the number of reactions. So as you add more and more molecules, the number of reactions that can take place goes up very quickly. And just like the button and thread web, when the ratio of molecules to reactions gets to a certain point, the whole thing becomes an interconnected network.

Now for the big question: can we imagine a reaction graph for a set of chemicals that could lead to the origin of life? In other words, what would the reaction graph of the primordial soup look like? Since there is really no way of knowing, the best we can do is to explore the idea in generic terms to see if anything interesting happens.

Catalytic Closure
Self-organization theory, by putting together the notion of phase transitions together with the complexity of chemical networks, actually shows how the interconnected network can become collectively autocatalytic (self-perpetuating, stable, and catalytically closed), meaning the whole thing can provide for itself, withstand being perturbed, and just keep on running – like a living organism. The secret ingredient is a decent helping of catalysts.

Without catalysts, the fact is that the network is pretty boring. Yes, once the ratio of reactions to chemicals gets high enough, the whole thing becomes connected. But just being connected isn’t enough to produce life. Chemicals just sitting in a beaker together don’t always react very quickly – even if they are connected. Like a bunch of shy kids at a school dance, they take a while to warm up to each other and start interacting. If the kids are too shy, the dance never takes off and everyone ends up going home early. Similarly, a beaker with a set of chemicals that don’t react very much isn’t going to lead to the emergence of life – that’s for sure. Thankfully, catalysts are big stars in the world of chemistry.
Catalysts push chemical reactions along. In the school dance, this would be the equivalent of a teacher convincing little Jimmy to ask Mary Sue to dance. So the reaction graph we’re after has to have catalysts. But since everything is connected, all chemicals are either substrates or products. That means that some chemicals will have to act as catalysts in addition to their day jobs as substrates and products. This is acceptable. There are plenty of examples of this in nature.

But the mere presence of catalysts still doesn’t get us to catalytic closure. In order for the system to become autocatalytic, a set of connected catalyzed chemicals must be present. Within the larger connected web of reacting chemicals, there must exist a subweb of catalyzing reactions. Catalytic closure, which Kauffman asserts should be a major component of any definition of life, means the system is continuously reacting using chemicals it has or produces. Little pockets of catalyzed reactions in the system won’t achieve this. The catalyzed reactions must all be connected to get closure. Luckily, with the help of our old friend statistics, this is not too hard to imagine.
The question now is what is the likelihood that a system with a connected catalyzed reaction subgraph would arise naturally in the primordial soup? Is it a fairytale or could it actually happen? To find out, we really need to know which chemicals can serve as catalysts in any given system. But rather than get tangled in analyzing each chemical, let’s just assume that each chemical has a one in a million chance of catalyzing any given reaction. As remote as these chances may seem, we can still easily show how increasing molecular diversity will inevitably result in the emergence of a collectively autocatalytic set.

Think back to the fact that chemical reactions increase exponentially as the number of molecules in a system increases. If you keep raising the diversity of molecules in the beaker, eventually the ratio of reactions to molecules will reach a million to one. Therefore, the average chemical in the system will undergo a million different reactions. So, probability tells us that each chemical will then catalyze at least one reaction (remember it has a one in a million chance). That means that the ratio of catalyzed reactions to molecules in the system would then be 1.0. At that point, it is highly likely that a large web will emerge, containing a fully connected catalyzed reaction subgraph. At that point, it will be collectively autocatalytic – and alive.

This explanation may seem too generic to be real but that is the point. The key to this line of reasoning is the idea that once any chemical mixture gets to a certain level of complexity, it is easy to see how living order can emerge. It needn’t necessarily even be organic; that just happens to be what was around on earth way back when. If we change the likelihood of catalysis to one in two million, well then the system just needs to have more living diversity, which is really just more time. The message is that the primordial soup had eons of time to work with. It is entirely plausible (and actually very probable) that the molecular diversity became sufficient to cause phase transitions that resulted in collectively autocatalytic, living systems. If this seems like the ultimate just-so scientific explanation, I understand. I’ve only scratched the surface on it. Stu Kauffman is the father of self-organization theory, so you can expect much better from him. Read his book for the juicy details – there’s depth to be absorbed.
My only aim in this lengthy discussion has been to propose a VERY plausible way to get around the supposed intelligent design problem. Once again, we are confronted with the limits of man’s imagination, not the limits of nature. So…I say again, please bring me an argument against evolution that holds water. Please.

Evolution Versus Creationism – Part 2 – Ring Species
January 17, 2005, 4:25 pm
Filed under: Science

Original Post (with comments)
It appears, from my inbox, that I’ve started something here. (He says as he feigns surprise.) All objections point to “intelligent design” as the achilles heel of Darwin’s elegant theory. It appears that this is the real anchor for creationists. They envision it as the AHA! moment in the debate, when deity denying evolutionists will scamper for the corners. Ahem. Not this one. But before I demolish this red herring of an argument, let me just put another nail in the coffin of one other creationist argument – the notion that the fossil record does not back up the assertions of evolution’s apologists. Let’s talk about ring species.

Ring species provide a unique glimpse into how some species came to be. Here’s the dull version: A ring of populations encircles an area of unsuitable habitat. At one location in the ring, two distinct forms coexist without interbreeding. Around the rest of the ring, the traits of one species change gradually through intermediate populations into the second species’ traits. Yawn.
Now let me just quote the master himself, Richard Dawkins:

The best known case is the Herring Gull/Lesser Black-backed Gull ring. In Britain these are clearly distinct species, quite different in color. Anybody can tell them apart. But if you follow the population of Herring Gulls westward round the North Pole to North America, then via Alaska across Siberia and back to Europe again, you notice a curious fact. The ‘Herring Gulls’ become less and less like Herring Gulls and more and more like Lesser Black-backed Gulls until it turns out that our European Lesser Black-backed Gulls actually are the other end of a ring that started out as Herring Gulls. At every stage around the ring, the birds are sufficiently similar to their neighbors to interbreed with them. Until, that is, the ends of the continuum are reached, in Europe. At this point, the Herring Gull and the Lesser Black-backed Gull never interbreed, although they are linked by a continuous series of interbreeding colleagues all the way round the world. The only thing that is special about ring species like these gulls is that the intermediates are still alive. All pairs of related species are potentially ring species. The intermediates must have lived once. It is just that in most cases they are now dead.
“Gaps In The Mind” from A Devil’s Chaplain (2003)

As has previously been stated, the fossil record is indeed discontinuous, but the preferred explanation is not that the life forms required by evolutionary theory did not exist. With ring species, evolving viruses and bacteria, the maturation of the human immune response, and many other examples, it’s obvious that evolution happened and is still happening in lots of circumstances. Nevertheless, it’s truly amazing how easy it is to disbelieve the obvious when you desperately want to. A good friend, a creationist no less, when commenting on women who know their men are cheating but stay anyway, is fond of saying, “They want to believe.” That always strikes me as funny. (You know I love ya, buddy.)

Evolution Versus Creationism – Part 1
January 16, 2005, 4:24 pm
Filed under: Science

Original Post (with comments)
There are far too many people who approach evolution as a theory which opposes most religious creation myths. So I have no choice but to spend some time on the evolution versus creationism debate. There are large books dedicated to making a case for creation science – as if it could ever be considered scientific. Rather than make this a treatise on the evolution versus creationism debate, I’ll stick to the best (yet startlingly inadequate) of the creationists’ arguments against evolution. The first is regarding the so-called “design problem”.

The question is how could evolution by way of natural selection have created such staggering living complexity. How could it create something as complex as a human eye, for example? After all, if evolution brings about changes gradually by acting on the occasional mutation, how could something as sophisticated as a binocular eye have emerged? To answer this, consider the time when the Earth was populated with simple animals – some of them with no eyes. Of course, natural selection was around back then – always finding the fittest animals to create subsequent generations. So the issue with binocular vision is the intermediate steps. What possible value could half an eye confer upon its host? It turns out that natural selection is quite handy at using seemingly innocuous talents to an animal’s advantage.

For example, imagine a population of little slug-like animals. These animals slide along the ground eating bacteria and such. They also happen to be the favorite food of another, more sophisticated crab-like animal. These crabs hunt during the day, gobbling up slugs whenever they find them. Now imagine that one day a slug emerges with a thin patch of cells on its dorsal side. It just so happens that this set of cells is light sensitive. Before your BS detector goes off, remember that evolution has millions of years to work with. Nature randomly explores the range of mutations quite well over that kind of time.

So the imaginary slug has light sensitive cells. When the slug is exposed to sunlight, these cells contract causing the slug to move away from the light. Now selection goes to work. Since the slug’s mortal enemy is the crab and the crab only hunts during the day, the mutated slug will enjoy a reproductive advantage over its contemporaries. During the day, while they’re randomly sliding around looking for bacteria, the mutant stays put in a shady hiding spot. The crabs pick off the others while the mutant is safe. It is easy to see how the mutant would live to make baby slugs. Over time, the population of slugs would be filled with light-sensitive individuals. Now imagine that a new predator comes on the scene.

This lizard-like animal hunts both day and night by using scent detection. The lizard doesn’t see very well so it uses its tongue to detect scent changes in the air. Now suppose that, when a slug feeds, the chemical reactions taking place give off a specific odor. The lizard has the ability to detect this odor. When it detects the scent, it follows it to its origin and eats the slug. So what happens if a new slug mutation causes the light-sensitive patch to be able to detect motion? Those with this new mutation would be able to detect the presence of the lizard and stop feeding. Those without it would continue to feed, oblivious to the threats around them. The continued emission of the odor would attract the lizard to them and that would be that. Again, thanks to selection, this mutation would flourish in the population.

These two just-so explanations are more than plausible given the long periods of time evolution has to work with. We can invent one after another until we arrive at an animal with a very sophisticated visual system. The point is that intermediate stages of design do exist and natural selection makes handy use of them. Moreover, given the choice between an argument that defies all natural explanation and an argument that is plausible, the clear thinker will choose the latter. There really is no design problem.

With the design problem worked out, I’ll turn to the question of transition fossils. Creationists typically do not accept the above explanation of the design problem because they argue that even if the intermediate stages were useful, the fossil record does not show the transitional forms that led to the current designs. They would say that there are no fossils of early light-sensitive slugs so they must not have existed. But this is not exactly true. In fact, the fossil record shows many intermediate designs. The transitional fossils between amphibians and reptiles are so various that it is extremely difficult to tell where one begins and the other leaves off. It doesn’t help matters that the prevailing system of classification of animals is somewhat arbitrary in its assignment of type.

For example, the dinosaur Archaeopteryx is clearly an intermediate between reptiles and birds – even though reptiles and birds don’t seem that closely related when you look at today’s zoological classifications. This is simply because early taxonomists didn’t have access to the information we have today. If we were to now reconstruct animal taxonomy based upon genetic similarity, we’d end up with a whole new classification system. This would be a big change so I doubt it will ever be done. But it doesn’t really matter. Even though this situation is a bit of a thorn in our side, the facts are still the same – there are plenty of transition fossils to lend credence to selection’s role in shaping life on Earth.

Creationists also like to highlight their misunderstanding of thermodynamics in their quest to overthrow evolution. Their argument is that evolution disobeys the second law of thermodynamics. They are referring to entropy, the idea that systems tend toward disorder from order. The order and complexity of living systems, in their view, is something that could not have emerged because systems should be moving toward disorder and simplicity. But this is simply incorrect.

For one thing, the second law of thermodynamics doesn’t really deal with order and disorder.  It deals with energy and how it flows in and out of systems. The second law of thermodynamics actually tells us that something complex can spontaneously emerge from something simple if the energy of the complex entity is lower than the energy of the constituents. Ice is a good example. But even if we put that aside, the second law also only deals with closed systems. An open system (meaning energy and/or matter can flow in and out of it) has no such restrictions. The creationist’s argument is like saying that a bicycle is impossible because entropy would force the components apart. But this is absurd. In this case, a bicycle is an open system. The energy applied by the mechanic to put it together is all it takes to make a bicycle from its parts. As long as living systems are open systems, the second law of thermodynamics can have no real bearing on their complexity. The inflow of energy and resources from the environment can account for any and all levels of complexity seen in living organisms.

The last major argument creationists tend to make against evolution is the silliest, in my opinion. The Bible lays out a timeline for man that is about 10,000 years long. Adam and Eve were supposedly created 10,000 or so years ago. But archaeologists have found multitudes of humanoid fossils that date back 2 million years. So creationists dispute our current dating techniques. They cite the decay of the Earth’s magnetism and the fallibility of Carbon 14 dating as evidence that the Earth is really only 10,000 years old. The reality is that the Earth’s magnetism is known to have reversed many times in its history. So it may be true that extrapolating the decay into the past indicates that the magnetism changed 10,000 years ago. But that certainly doesn’t lead to the conclusion that the world is 10,000 years old! Furthermore, Carbon 14 dating has been proven accurate countless times. This is just the kind of denial of reality that comes with trying to make facts fit theories instead of the other way around. It doesn’t work.

I’ve read several books on creationism and I have yet to run across one that puts forth an even remotely reasonable argument. As always, I’m willing to change my mind, but not based upon what’s currently out there. Anyone got anything better?

Hope, Despair, and the Need to Believe – An Argument for Reason
January 7, 2005, 4:21 pm
Filed under: Culture and Society, Enlightened Living, Philosophy, Science

Original Post (with comments)
I want to follow up on a comment about the post from two days ago. Michael Gersh (of Zero Base Thinking fame), has this to say about the opinions of many of secularists who come off more as anti-religious than agnostic:

Maybe I have missed something here, but isn’t religion, or at least the need to believe in that which we have no logical answer for, hard wired into the human brain, by the same forces of evolution that shaped the rest of our ouvre? Smug secularists posting here might believe themselves to be above this basic human need, but I think that this is a distinction without a difference. While many so-called rationalists might disbelieve the Bible’s miracles, they merely believe in something else. Maybe global warming, or other environmental belief, that Michael Crichton has so presciently perceived as akin to religious belief. Maybe it is some sort of overreliance of other human constructs, such as the social contract, or even the supremacy of rationality itself.

None of us are immune to this human tendency to believe in some specific explanation for an essentially unknown, and perhaps unknowable condition.

I don’t think we necessarily have an inherent need to believe in the inexplicable so much as we have a hard-wired need to explain our environment, if for no other reason than to connect cause with effect. Before we can associate a certain set of conditions with a certain outcome, we have to be able to identify and categorize what we perceive. If a caveman witnesses the mauling of a fellow tribesman by a lion, his mind notes the existence of a furry and ferocious entity. It then categorizes it as an entity that can kill humans. The next time he sees one, even if it looks a little different (perhaps it’s female and the first was a male), he will generalize that he is in danger. This is key mental adaptation for survival, one that is well distributed throughout the animal kingdom. But with humans, there is a layer of cognition that does not come installed in the brains of our animal brethren. This is where the belief problem comes from.

In my view, non-human animals, though driven by emotion, are supremely rational in their perception of their environment – water is wet, always. They cannot be otherwise. Humans, however, have the free will to choose to interpret their world irrationally. A human can decide that a cobra is not dangerous, even when his animal emotions drive him to act as if is. Though this free will undoubtedly serves us well, it has a downside. We can fall victim to false hope.

In a paper called, “The Evolution of Hope and Despair,” University of Michigan professor of psychiatry and psychology, Randolph Nesse, lays out the idea that hope and despair are simply emotions driven by our appraisals of whether or not our environment will favor or disfavor the realization of our goals. Like other emotions, they serve to drive us to do things that will keep us alive long enough to reproduce. They are sort of the uber-assessors of our surroundings. If we find ourselves in circumstances that bode well for us, we have hope, so we stick around. Alternatively, if our circumstances look grim, we feel despair, which pushes us to change our situation. But what happens when we cannot explain our environment? What happens when we have no categories for the phenomena we witness?

As an absurd example, suppose a caveman stumbles upon a spaceship. Neither he nor any of his tribesmen have ever seen anything even remotely like it, so they are perplexed, to say the least. But uncertainty does not make for decisive action, which, in harsh times, is an utter necessity. Indeed, in a heated competition for survival, prolonged contemplation of the unknown is often a grave mistake. Conclusions must be drawn so that decisions can be made. The human mind, given the choice between choosing an explanation for the unknown, even if it’s a bad one, and choosing to leave the matter unsettled, will, therefore, choose an explanation. But how?

Our rational animal perceptions will provide us with competing explanations for what we observe. Then, we will decide which one to believe – by choosing the one that offers the most hope. Just as we’re emotionally drawn to situations that give us the warm, fuzzy feeling in our stomachs, so are we drawn to hopeful situations. So, while I’m not prepared to say that we have inherent need to believe in irrational things, I will say that our need to explain our world coupled with our attraction to hopeful situations sets us up to fall victim to irrationalism, and not just with respect to religion.

The lottery is one of the ultimate examples of false hope. We’ve all seen poor people in line at convenience stores spending money that would more intelligently be spent elsewhere on scores of quick picks and scratch-off games. In fact, on more than one occasion, I’ve heard people say, “When I win the lottery, I’m going to…..” Now, it’s one thing to say this in jest; it’s quite another to believe it. Many people really do, and this is a shame because I am convinced that this false hope removes much of the necessity to recognize reality for what it is and to act accordingly.
It is a fact of life that many people are born into terrible circumstances. Those who rise above them are the ones who see and accept their plight for what it is. This acceptance is the first step in determining how to overcome whatever impedes their achievement of their aims. False hope blurs reality and fosters inaction, or worse yet, useless action. The same is true of irrationality.

I think there are two types of secularists – the ones who apply rationality to all things, including religion, and the ones who happen to be rational about religion, but have no particular allegiance to it in other matters. I am one of the former. Michael, I think the smug secularists you refer to would find themselves among the latter. In any case, there is one staggeringly straight forward fix for the problems that come from the need to explain and the attraction to hope. It is called critical rationalism.

We start by admitting that we can be certain about nothing. Nothing. Then, we decide to put everything into one of three categories – things we believe, things we do not believe, and things we choose to leave unsettled. To determine what we believe and what we do not believe, we demand evidence, and we favor evidence that disproves assertions over evidence that proves assertions (since we can never really prove anything). We weigh the evidence for possible explanations and decide what to believe and disbelieve, and when the evidence is not compelling one way or another, we abstain. We are not cavemen, which means ambiguity is not dangerous for us. We do not have to act or die. This means that we can (and must) become comfortable with uncertainty. If we are successful at being critically rational, we are immuned from the perils of false hope and irrationality. But rationalism for the hope-addicted mind does not always come easy.

At the end of the day, each of us must decide how we will think. If we do not, we will vacillate opportunistically between rationality and irrationality – invoking either one based upon personal convenience. But deciding to be rational at all times is like deciding to be nice all the time. It’s an aim, an intention. We will, from time to time, falter. However, as long as we recognize the value of rationality, we will get back up and keep moving forward. That’s life. It’s best if we focus on our own journey and leave the arrogance to the certain, who always learn sooner or later that nothing is certain.

Your Genes Want You To Drive A BMW
December 27, 2004, 4:10 pm
Filed under: Culture and Society, Enlightened Caveman Concept, Science

Original Post (with comments)
Given some of the mail I’ve received of late, perhaps its time to go back to basics…

Your genes want you to drive a BMW. They also want you to be thin, tan, and to have a lovely smile. Your genes want you to be the life of the party – perhaps a musician or an artist or a celebrity of some sort. “What?” you say. That’s right. Though you probably don’t realize it, humans are genetically inclined to be aware of who’s at the top of the social totem pole, and more importantly, to emulate whatever it is those people did to get there.

According to evolutionary psychologists, our genes build our minds to pursue status in social groups. This is because, long ago, when humans were still cave-dwellers, status meant the difference between life and death. Being among the best hunters and warriors was a sure way to obtain food when food was scarce. Therefore, Mother Nature, ever the tinkerer, discovered that humans who were genetically driven to pursue status would outlive those who were not. Thus was born the status-seeking gene, and it has been with us ever since. (In truth, it is a gross oversimplification to assert that there are specific genes for this or that attribute. It’s just an easy way to say that a trait is largely genetic.)

In any case, Robert Wright chronicled this and other insights into the evolutionary history of the human mind in his 1994 best-seller, The Moral Animal. As astounding as the book was, a decade has passed and most folks still don’t know anything about why they think and feel the way they do. This is a real problem, unless of course everyone can have a BMW, and assuming that having a BMW is really all it’s cracked up to be.
It breaks down like this. From a genetic perspective, modern humans have the minds of cavemen. As soon as humans could organize sufficiently to protect themselves from nature and other humans, and could consistently procure food in mass quantities, natural selection no longer had an easy task of separating the fit from the unfit. Fitness became more a function of luck or circumstance than strength or skill, at least when it came to living long enough to reproduce (which is the only real goal of our genes). The process that had been shaping the human mind for eons suddenly ground to a halt. This is believed to have happened somewhere between 20,000 and 100,000 years ago. Since then, the genes that code for our minds have not changed significantly. They just get reshuffled again and again, generation after generation. And here we are, dozens of millennia later, mostly unaware of the degree to which the environment of our ancestors affects our day-to-day lives.

Seeking status in ancient times was a survival necessity. In modern times, it is a fool’s errand. This is because what counts for status today has nothing to do with survival. Who’s at the top of the social totem pole these days? Celebrities. Whether we’re talking about sports stars, musicians, actors, business tycoons, and even religious figures, one thing is certain – the masses are paying close attention to what they do, and, in many cases, they are following suit.

Those who get the most attention in our society are the role models, whether they like it or not. They set the cultural agenda. It has always been so. From Elvis’ sideburns to Madonna’s material girl get-up to the current obsession with “bling,” it is instantly apparent how much popularity equals status in our modern world. From shows like Entertainment Tonight and magazines like Us and People, we can see that America’s obsession with stars is a multi-billion dollar industry. But doesn’t anyone ever wonder why so many people across such a diverse land would share such a shallow proclivity?

As we learn more and more, it becomes clearer and clearer that it’s genetic. But that doesn’t mean we have to give in. As they say in the world of addiction, admitting that there’s a problem is half the battle. Like it or not, we currently find ourselves in a battle for sanity, or at least emotional stability. How many among us are dying to drive a BMW, not because it is a superior automobile, but because of how it will be perceived by friends and acquaintances? How many are depressed when they look in the mirror because they don’t resemble the celebrities they so desperately envy? More generally, how much of what we do is for show rather than for substance? It doesn’t have to be this way.

If we’re going to make any more progress as a species, we’re going to have to recognize that our minds are constructed from the genetic blueprints of our cave-dwelling ancestors, blueprints that were designed for a world that no longer exists, blueprints that are at work every day pushing us to obtain status in our social endeavors. That’s our starting point. From there, the fix is within our reach. Indeed, many have overcome their genetic imperatives.

As a species, we have a long history of taming our genes. Birth control, monogamy, the rule of law, capitalism, and gene therapy are all examples of mankind overruling genetic influences in favor the conscious desires of human beings. A cursory look around reveals that there are many who have rationally concluded that society’s value systems are fickle at best, and demented at worst. Some folks have taught their genes not to want a BMW, at least not simply because the possession of a BMW means they’re somebody. They have deliberately concluded that wealth does not necessarily equate with value as a human being, nor does physical appearance or the ability to excel in sports or in the arts. Though any one of these things may (and often should) be admired by society, at the end of the day, none matters in and of itself.

John Kerry jokingly said during the campaign season that he and George Bush had “married up.” That a statement like this is categorically unremarkable is a testament to how much the awareness of and quest for status imbues our collective perspective. If we are to keep our genes from having their way with us, the time has come to start recognizing when our concern for status is getting in the way of our enjoying life. In other words, what do we have to give up so our genes can have a BMW? Asking questions like this is the first step in enlightening the caveman in all of us.

Random Thought on the Variation in Animal Behavior
December 17, 2004, 3:56 pm
Filed under: Science, TV

Original Post (with comments)
I love nature shows, but I’m always alarmed at the confidence with which folks like Steve Irwin and Jeff Corwin approach dangerous animals. They consistently refer to the exhaustive body of research on these animals as evidence of what these critters will do from moment to moment. This seems odd to me, even though the fact Corwin and Irwin are still alive reasonably substantiates their credibility. What gets me is this: how is that human tendencies have so much variation but animals are fairly well predictable?

I mean, there are good people who adhere to social norms, but there are also bad people, even evil people, who have no regard for others. The behavior of these kinds of people cannot be even remotely predicted. Are there not equivalents in the animal kingdom? Are there not “bad seeds” who, far from doing what researchers expect, will jump at the opportunity to maul a supremely arrogant human? This thought grips me most when I see marine biologists swim with sharks. Wasn’t the shark in Jaws one of these bad seeds? I know, it’s just Hollywood, but still. I saw a show a couple of nights ago where a guy was swimming with no weapons and in no cage with a slew of bull sharks. He was obviously very comfortable – the crazy bastard. Why is it that the behavior of such dangerous animals can be predicted so consistently, yet humans are all over the map?

Maybe it’s human culture that builds in so much variation in behavior. I don’t know, but you can count on one thing – if I ever encounter a bunch of bull sharks, I’m exiting the water immediately.