Evolution

My God...they're evolving!

I was reading Micheal Crichton's Jurassic Park sequel, The Lost World when I discovered it. By bringing dinosaurs out of pre-history, setting them down on a modern tropical island, and then suggesting that they were adapting to their new environment, Crichton confronted me with the amazing idea that the word "species" did not in fact denote a static thing, but rather something that flowed through time; something that evolved.

And by suggesting that, through this process, his already terrifying dinosaurs were becoming even more dangerous and cunning, Crichton successfully imbued the concept of evolution with a thrilling poignancy that immediately captured my imagination. The very next book I signed out of the library was The Origin of Species.

At the time I was sixteen, and I had just dropped put of school having concluded that I was wasting my time there. In retrospect - since my interest in evolution played a key role in my eventual return to the educational system - this seems more than a little ironic. But at the time, my discovery actually seemed to forcefully justify my decision to drop out of school. After all, why had I been left to languish in math, art, or "business education" classes, or been forced to read A Midsummer Nights Dream (for crying out loud), while ideas this cool remained unexplored and unmentioned? Why the hell wasn't I told about evolution in school ???

Even more disturbingly, I now know that I was not a unique case because I have met many people who badly misunderstand Darwin's theory. This is a grave tragedy: evolution by natural selection represents the single most important scientific discovery human beings have ever, or will ever make. I sincerely believe that in endeavoring to understand evolution, one becomes a better person; and that in attempting to effectively communicate it to others, one also makes the world a better place to live.

In this spirit, let me pose you a question: do you think you understand biological evolution? Here are the four most common evolution-based misconceptions that I encounter, and the reasons why they are just that. I bet you ten bucks that you've fallen for at least one of them.

Music

"The trills, chills, and tears we experience from music are the result of having our expectations artfully manipulated."

- Daniel J. Levitin, This is Your Brain on Music 

If you were to hear every note contained in a particular song played all at once, you wouldn't get much out of the experience: one of the most important aspects of music is that it presents us with a pattern that unfolds over time.

In doing so, music gives our brains the irresistible opportunity to second-guess how it will unfold. We do this based on clues we have gleaned from our experience with the tune thus far, as well as on our past experiences with music in general. And the music we tend to enjoy is that which we can anticipate with a reasonable degree of success. But while good music must not altogether defy our expectations, it is also essential that it pleasantly surprise us from time to time. As we all know, when a tune is too predictable, we become bored with it; in a way, good music is very much like an enjoyable game, in that it must be challenging, but not too challenging, to anticipate.

I think Mr. Levitin's perspective provides a good starting point from which to approach some music-related controversies. For instance:

• Do plants like music, too?
• And what about animals other than ourselves? 

Many, many people would have you believe that yes, and yes: they do. Are these people just over-anthropomorphizing? Or is their logic, in fact, sound?

Recycling

Nobody likes a cheat. But did you know that neither do monkeys, birds, and insects? For us organisms, the ability to protect ourselves against parasites is of prime importance - and that includes parasitic members of our own species. Many animals have responded to this threat by evolving an intrinsic capacity to both expertly detect, and instinctively resent, cheaters.

But humans have become especially good at this. So even if I preface my admission by first informing you that I don't own a vehicle; bring my backpack to the grocery store; stay away from over-packaged products; don't have a lawn; and have personally planted well over a million trees by hand; you are still likely to feel a twinge of annoyance when I tell you that I don't always recycle. This suggests that it's not so much my net impact on the environment that so bothers you, as it is the simple fact that I'm cheating.

But am I, really? After all, I need look no further than Wikipedia to see that there are innumerable controversies surrounding the practice. Micheal Moore, with his book Stupid White Men, made me suspect that much of what I recycle ends up in a landfill anyway, and Penn &Teller used this episode of Bullshit! to convincingly argue that in many cases the landfill option is actually the more environmentally sound alternative.

But of the three, recycling is easily the biggest pain in the Rss. Like any sensible person, I don't want to pollute, or be thought of as a social parasite, but neither do I want to wash, sort and recycle my garbage if it isn't going to do any concrete good. 

So! Should I just shut up and recycle? Or is it your disapproving attitude that should be curbed?

Shaving

Almost everyone selectively removes disgraceful body hair, and many of us do it as a matter of routine. We subject ourselves to the agony of waxing, and spend small fortunes buying razor blades and various shaving lotions. But despite this investment in time and resources, we don't think about it much; it's a means to an end, and a fairly mundane and straightforward one at that. Because of this, even if you consider yourself to be an expert leg-waxer or face-shaver, a bit of skepticism and a dash of research might still confront you with some surprising and practical insights.

Race

"Now, I don't see race. People tell me I'm white and I believe

them, because I belong to an all-white country club."

- Stephan Colbert

The war on racism often manifests itself as a war on race. This is evidenced by slogans like "there is only one race - the human race". And the often-expressed hope that the 2008 election of Barack Obama would usher in a "post-racial" era suggests the complete abolishment of the idea of race is seen as a kind of Utopian ideal. The spice of life - variety - apparently goes with people like cayenne pepper goes with bubble gum ice-cream.

The argument against race comes in three primary flavors:

1. It is an artificial concept, that does not exist outside our minds.
2. It is a useless concept from which no good has - or will - ever come.
3. "Race" always has and will continue to do more harm than good: it is a destructive and divisive concept that can do - and has done - great harm to humanity.

Is "race" really nothing more than a destructive human construct? Have I finally bitten off more than I can chew? (hehe)

The olympics

The winter Olympics are set to commence in Vancouver but a hop,skip, and a ferry ride away from where I currently sit. This immediacy has moved me to ponder the practicality of the Olympic phenomenon more closely.

The games are magnets for controversy, so it's easy to find good reasons to oppose them. The decision to host the 2010 games has been opposed by many who are concerned about their effect on the homeless; Native rights; the environment; the local economy; and media freedoms (you might be interested to hear of the recent experience of a visiting American journalist if you haven't already). As a counter to these concerns, proponents of the games tend to point to a few key pros. I have attempted to investigate these.

So how do the Olympic games allegedly benefit the human race? Do they increase our average level of physical fitness? Are they good for the economy? Do they help foster international togetherness? More...

FITNESS

The modern Olympic games owe their existence in large part to the actions of a French Baron, who was convinced that his country's catastrophic military defeat by the Prussians in 1871 was in part due to the inadequate physical conditioning of the French troops. Today, the argument that the games contribute to a populations average fitness is predicated on the idea that the Olympic spectacle inspires amateur athletes.

Moreover, a high gold medal tally is seen to reflect positively on a nations dedication to health and sporting excellence. Rich industrialized nations are therefore expected to dominate the standings, and a failure to do so can have political consequences. For instance, after Australia failed to meet it's goals in the Beijing games last year, a great cry went up in support of increased funding of Olympic sports programs. Some even demanded more gold medals from future athletes "at all costs".

The Australian government responded by commissioning a report into the current state of it's national sports programs, and it's findings are proving interesting to people the world over (including here in Canada). Released last month to much shock and horror, the report actually recommends that Australia's quest for Olympic gold be tempered. According to it:

• gold medal tallies should not be the units by which national sporting success is measured.
• rugby and cricket - sports Australians actually enjoy - should be favored over relatively unpopular Olympic sports like water-polo and archery.
• and community and school sports programs should be favored over those for training elite Olympic athletes.

Although all this makes pretty good sense to me, I am unsurprised that the report has been showered in criticism and distain. "So much for excellence!" critics sneer, many of whom see the report as a great insult to Olympic athletes. The 'quest for gold' is seen to be a national obligation in Australia just as it is in many other parts of the world.

But it is precisely for this reason that Olympic success is usually achieved by investing vast resources in a few, select athletes who are then able to dedicate their lives to their sport; receive the best instruction and medical treatment available; train at high altitudes; and obtain the latest in "performance-enhancing" technology (like the seemingly crucial new swimsuits that appeared in Beijing last year).

In considering the winter Olympics, I can't help but wonder if the money spent training world-class biathalon, luge, and speed-skating athletes might not also be much better spent if the goal really is to increase general fitness. And I also think it's reasonable to suspect that the inspirational value of these and many other Olympic events is greatly overshadowed by the couch-potatoing they encourage.

ECONOMIC BENEFITS

Nations also compete intensely for the honor of hosting the games, as evidenced by the bribing of previous  International Olympic Committee (IOC) board members, and the recent unsuccessful but energetic attempt of Barack Obama and Oprah Winfrey to secure the 2016 Chicago bid.

This is despite the fact that the only city ever to have actually profit from the experience is Los Angeles - and even they only got it right the second time around. In fact, the Olympics are almost invariably billions of dollars over budget when all is said and done. The quintessential victim of Olympic overspending, Montreal took 30 years to pay off the huge debt it incurred hosting the 1976 summer games. Most of this money was spent on the building of a stadium that is currently badly underused.

Critics argue further that while Olympic infrastructure can see decades of continued use, the creation of it serves to concentrate resources in the cities at the expense of the surrounding countrysides. In any case, it is certainly true that rural folk who might not get to take advantage of the improvements in infrastructure still must help pay for them.

Not everyone tends to lose out at the games of course. Various private interests are well served: television broadcasters expect to make a tidy profit for example, as does the IOC itself. Host cities hope to recoup their expenditures by attracting foreign investment, and corporate sponsors and incumbent politicians stand to cultivate valuable PR.

But it seems to me that economic arguments for the Olympics depend largely on the so-called "trickle-down effect": the idea that the taxpayers and consumers (who are ultimately footing the bill) benefit indirectly from the endeavor. And it is worth noting that "trickle-down economics" is a highly politicized and controversial topic unto itself.


INTERNATIONAL TOGETHERNESS

The games are also supposed to facilitate a greater understanding between cultures, and serve to help foster world peace by uniting all of humanity through the universal "Olympic values" of excellence, sportsmanship, and fun. Here's where I get to sound really cynical.

A major problem with these claims is that politically-inspired Olympic boycotts are far from uncommon: the American boycott of the 1980 games in Moscow and the retaliatory USSR boycott of the 1984 Olympics in Los Angeles are only the best such examples. (A boycott of the 2014 games in Sochi, Russia has also been recently called for by the Georgian government.)

Another problem stems from the fact (mentioned above while considering FITNESS) that Olympic success is often considered a matter of national prestige. Because of this, even when the US and USSR did share the Olympic stage their contests were often invested with political significance, as the athletes produced by the capitalist system competed with those produced by the communist system. The euphoria surrounding the 1980 American hockey victory over the Russians (the "Miracle on ice"), was no doubt largely due to this effect.

When there are positive political effects, they tend to be limited and sadly temporary - like the removal of openly anti-semitic signage for the 1936 Berlin Olympics in Nazi Germany, or the greater media freedoms allowed by the Chinese in 2008.

In addition, it should be added that the games have been cancelled 3 times due to global conflicts; and I know of at least one example where an international (albeit non-Olympic) sporting event may have actually contributed directly to armed conflict.

To me, all of this suggests that those who think that the Olympics lead to peace have confused the cause with the effect.

* * *

I don't necessarily mean to suggest that the Olympic games should be terminated; I know that many people enjoy participating in and watching the Olympic games, and that is surely worth something. But it does seem to me that large holes exist in the foundations of many pro-Olympic arguments. And in ignoring them we simultaneously deny ourselves the opportunity to address them. Allow me to leave you with what I feel are the most pressing questions that should be asked of the modern Olympics:

• Is it really necessary that athletes be associated so closely with their respective nationalities?
• Luge??! Really - come on!  What the hell is with the LUGE??
• DOUBLES LUGE?? You've got to be kidding me.

Global warming

In preparation for my post on the Gaia hypothesis, I went to see my former Geo-science instructor with some questions. We got to chatting about global warming and I causally mentioned that it seemed to me as if the denial of man-made global warming had been declining in the last few years. I was surprised when he immediately disagreed with me, but I nonetheless remained stubbornly convinced that I was right.

The next day, the "climate-gate" story broke, and my poor illusions shattered in a manner most spectacular.

Is global warming still real? Or has climate-gate really exposed it all as "the greatest scam in history"? More...

First of all I should point out that I am aware that I am no climatologist, and I do not intened to here make a water-tight case for global warming. However, in considering the controversy surrounding this phenomenon, it seems to me important to remember these three simple facts:

1) we know that the "greenhouse effect" is real, otherwise life as we know it would not exist;

2) we know that atmospheric gases (such as water vapor, carbon dioxide and methane) are responsible for it; and

3) we know that humans are responsible for the emission of large quantities of some of these gases into the atmosphere, mostly via industrial and agricultural activities.

While this doesn't mean global warming is necessarily inevitable (it could still be argued that there are other, as-of-yet unknown factors, like atmospheric aerosols, or cosmic rays, that could be counteracting the increase in atmospheric greenhouse gases), it is important to keep in mind that the theory of global warming is by no means based entirely on the observation that the Earth is getting hotter; it would actually be surprising if this wasn't the case.

But - unsurprisingly - the planet does seem to be getting hotter, and a huge body of evidence exists to corraborate this notion: melting glaciers and icecaps the world over; the increasing incidence of droughts and tropical storms; and ocean acidification, are just a few examples. While some of this might be disputed, the key point to be made here is that the evidence for global warming has been derived from several very different fields of inquiry: if all this evidence has indeed been fabricated, climatologists have a great many co-conspirators.

(Here's a cool history of the scientific debate, in a sweet English accent to boot)

"So then what about the 'climate-gate scandal'?"

When you consider all of this, the idea that a handful of hacked emails from a single institution could somehow show that the theory of anthropogenic global warming is a huge conspiracy is absolutely laughable. Even if it turns out that the scientists involved are indeed guilty of scientific spin-doctoring the debate over global warming should not be effected by this affair in the least.

However, as of this writing, it is far from certain that these emails do show that spin-doctoring has occurred. But none of this has stopped the story from wildly snowballing, and it did not stop The Telegraph from heralding it as "the final nail in the coffin of anthropogenic global warming". Meanwhile, heated "debates" (like this gem) reappeared on the airwaves. I think climate-gate will prove to be more of a media scandal, than it is a scientific one. It's another "balloon boy"; another Peruvian human fat smuggler: it's a non-story.

(The English dude also did this excellent video, dismembering some of the media's wilder claims about climate-gate.)

Let me be clear: it is important not to be too credulous, and it is important that we are able to have a completely open discussion and consider all of the possibilities. But the arguments of the outright deniers of anthropogenic global warming have become increasingly far-fetched, and I think that the most salient aspect of the climate-gate affair is that it has highlighted the resort of many global warming "skeptics" to conspiracy theory. And those that have done so have, in my opinion, effectively exited the debate.

An international climate summit commenced today in Copenhagen, Denmark. It is set to be the largest and most important ever held, and hopes are high that an agreement to replace the expiring Kyoto Protocol might be reached. If it is to succeed, people need to be knowledgeable and enlightened enough to be able to see past distractions like climate-gate, because the media are doing us few favors.

The gaia hypothesis

The "Gaia hypothesis" is the brainchild of the "independent scientist" and interesting character James Lovelock, who in the early 1970s proposed that the entire Earth was alive.

According to him:

"During the time, 3.2 billion years, that life has been present on Earth, the physical and chemical conditions of most of the planetary surface has never varied from those most favorable to life".

He claimed that this was because the living and nonliving components of the world cooperate, and together display a capacity for self-regulation that is (he said) analogous to homeostasis. Thus, the whole of the Earth, by extension, is analogous to a massive single organism. He named this "organism" after the ancient Greek goddess of the Earth, "Gaia" (This NOVA documentary does a great job of thoroughly explaining the reasoning behind the idea.).

Many people see this idea as the scientific embodiment of "Mother Nature", and though to some the existence of Gaia seems incredibly far-fetched, others see it as being rather self-evident and undeniable; where some see an insightful revelation and appealing world perspective (especially when considering phenomenon such as climate change), others see a misguided logic, or even an ideologically-inspired pseudoscientific concept. But despite the controversy, those who actually understand Gaia (at least as Lovelock conceives it) are few and far between.

Why is an understanding of Gaia so elusive? And is it a valid scientific concept? More...

For starters, the very name, "Gaia", is highly misleading, and often provokes an automatic bias one way or the other. Lovelock admits it has given him trouble in terms of scientific acceptance, although I have not heard him lament it's effect on popular acceptance (or book sales). In any case, he hasn't exactly done a great job of compensating for this effect with his language (by referring to Gaia as "she", for example).

Secondly, Lovelock himself now has a vastly different conception of Gaia than he did forty years ago. He says this is because he has come to "better understand Gaia theory" over the years, but it might be more accurately stated that it is because he has had to disown many of his original claims: he has now abandoned the idea (expressed in the quote above) that there is such as thing as a particular set of conditions that are "most favorable to life"; and he no longer insists that Gaia is consciously trying to self-regulate itself. I personally think it is to his credit that he has recognized these blatant errors, and has attempted to compensate for them. But it is important to remember that these were not small details: they were some of his main points!

One inevitable consequence of this back-peddling has been that Lovelock's Gaia has been made a bit mundane- it's implications are certainly distinctly less profound than they were forty years ago. Another consequence is that many different interpretations of Gaia now exist. This huge range of views on the subject makes it almost impossible to determine what, exactly, someone actually means when they use the term "Gaia hypothesis", which makes even more difficult to properly understand and scrutinize.

"Ok, so people dont agree on what it is. But is Gaia real?"

It is worthwhile noting that the Earth is not really analogous to an organism at all. In fact, the ability to perform homeostasis is but one of life's defining traits. For example: the Earth doesn't reproduce; and neither did it undergo evolution by natural selection. And yet every other single thing that we describe as being "alive" has met these conditions. By saying "the Earth is alive" what you are, in effect, doing is redefining the word "life"; Lovelocks great analogy is nowhere close to perfect. Gaia isn't an organism: "she" is just a system (I doubt, however, that "the System hypothesis" is a title that would have moved quite as many of Lovelock's books).

It is also interesting to ponder how humans fit into all this. Are we a part of Gaia or not? This is not a petty distinction: if we are then Gaia is in trouble: humans aren't exactly helping to regulate the climate at the moment. On the other hand, how can it be that humans are distinct from Gaia? Are we not also of the Earth?

In this interview with the CBC's David Cayley, Lovelock explains that the greatest opposition to this theory has historically come from biologists, who (according to him) correctly perceive it as threat to Darwinian orthodoxy: after all, how could Gaia ever arise from a simple struggle between organisms for "the survival of the fittest"? He even suggests that the theory of evolution should be modified to account for the existence of Gaia.

But I think Lovelock missed the point: after all, the idea of an ecosystem is not foreign to Darwinism, so why should the idea of a global ecosystem constitute a threat to it? I think the bottom line is that where Lovelock sees Gaia, biologists see an equilibrium - and they are distincly unsurprised by this because equilibriums are the natural state of any system. Gaia does not threaten Darwin: it is simply that a Darwinian outlook does not require Gaia to explain anything.

"So what does Gaia explain?"

The quote I used at the beginning of this post suggests that Lovelock's original intent was to explain why "the planetary surface has never varied to those most favorable to life". But as we have seen, even he now admits that this is based on a false assumption. So I find myself at a bit of a loss as to how to answer this question.

And it occurs to me that an idea that is so grand to deserve the name "Gaia" - and one that increasingly referred to as a "theory" - should be able to do a lot better than this. Maybe I just don't get it, but as I currently see things, Gaia - however appealing - is just a highly misleading and confusing concept, that also happens to be entirely devoid of any practical value. Don't get me wrong: James Lovelock is no crackpot by any means. He has made undeniably valuable contributions to science. But I find myself currently of the opinion that the Gaia hypothesis is just not one of them.

The full moon

That idea that the full moon effects human behavior is largely taken for granted, and is probably nearly as old as speculation itself. The word "lunacy" suggests that the ancient Romans (who worshiped the moon goddess, Luna) subscribed to this idea, but I doubt they were the first.

Today, this belief remains largely unquestioned. And why not? The moon causes the tides; informs the advice given by the Farmer's Almanac; (allegedly) regulates human menstrual cycles; and makes wolves howl. So it was only very recently that I even bothered to give this little tidbit of common knowledge much thought. But one day, I ventured to wonder if the moon really was periodically wresting my precious inhibitions from me, and if so, how I could put a stop to it.

Can the moon really effect our behavior/ physiology? If so, is the effect truly more pronounced when it's full? And if not, what about claims that women are "in sync" with the moon? More...
I've generally encountered two different explanations as to how the full moon allegedly effects us: I will call them the gravity theory; and the moonlight theory. The proponents of the gravity theory tend to say things like:

"Everyone knows that the moon has an immense effect on the ocean, and everyone knows that people are - like the ocean - mostly made of water, so the moon must effect us too, right?"

Well actually, no. In fact, it is incredibly easy to calculate the gravitational "pull" that the moon exerts on you, and it turns out that taking an elevator has a vastly greater effect on your physiology; and I don't mean to play up the physiological effect of elevators.The moon's effect on the ocean is due to two things: the size of the ocean; and the fact that is fluid. People - puny, viscus things that they are - are actually effected much differently than the ocean, regardless of their percentage water content.

And anyway, according to the gravity explanation it is the new moon - not the full - that should have the greater effect, as it is only then that the gravitational influence of the sun and the moon are complimentary, as you can see in the image above. But, again: even with the sun and moon so ganging up on you, their combined gravitational influence on you really is incredibly infantesimal..

The moonlight theory on the other hand, holds that:

"To animals the world over, the full moon is associated with a change in behavior, often by acting as a mating signal. So isn't it possible that some sort of human "sensitivity" to the light of a full moon might be a kind of vestigial instinct, inherited from our evolutionary ancestors?"

First of all, even if this were true, modern dwellings and illumination techniques often obscure the moon's light altogether. But the best point to be made here is that there just really is no evidence that the full moon has any special effect on humans; we just don't seem to act any differently when the moon is full.

Don't get me wrong: full moon is beautiful to look at, can provide great lighting, which can help you feel romantic, and I'm sure that the knowledge the moon was full might has helped convince many a person to act like an idiot on more than one occasion. But the idea that such behavior can be directly caused by a full moon is, I think, false. And there really is little in the way of objective evidence to contradict me.

"So then what about the apparent correlation between the moon and human female menstruation?"

Ladies, if I may be so bold as to propose it, this apparent correlation is almost certainly just a coincidence! As the astronomer George O. Abell wrote:

"The moon's cycle of phases is 29.53 days, while the human female menstrual cycle averages 28 days (although it varies among women and from time to time with individual women); this is hardly even a good coincidence! The corresponding estrus cycles of some other mammals are 28 days for opossums, 11 days for guinea pigs, 16 to 17 days for sheep, 20 to 22 days for sows, 21 days for cows and mares, 24 to 26 days for macaque monkeys, 37 days for chimpanzees, and only 5 days for rats and mice. One could argue, I suppose, that the human female, being more intelligent and perhaps aware of her environment, adapted to a cycle close to that of the moon, while lower animals did not. But then the 28-day period for the opossum must be a coincidence, and if it is a coincidence for opossums, why not for humans?"

Since we entirely lack any decent explanation as to how it might be otherwise, this seems to me be an etirely reasonable assumption. Moreover, according to Wikipedia, no study has ever "demonstrated the synchronization of women's menstrual cycles with the lunar cycle."

This means that virtually all the talk of the supposed "emotional/physiological effects" of the moon is, as far as I can tell, full of it. And I think that's just fascinating.

(Special thanks to Dr. Alf!)

Moral disagreements

I have heard it said that even though everyone agrees that firetrucks are red, we all actually "see" a different color when we look at one. For example, my "yellow" might be your "pink"; we just don't know it. The band Greenlaw has written a song wherein the idea that "we don't see the same color blue" is utilized to great poetic effect.

It's an interesting idea, but I think it is largely untrue (except in special cases, like color-blindness): our sense of sight is just too fundamentally important; too fine-tuned; and too old (in evolutionary terms), to vary as much as that. But when it comes to our sense of morals, the same cannot be said: morally speaking, it may in fact be truthfully said that we don't all "see the same color blue". More...
This is important because many of the modern world's most polarizing issues - though they appear to be intellectual divides - are in fact moral divides. The distinction is not trivial: if issues like these are treated as intellectual divides, then our opponents must be either misinformed, stupid, or amoral; if they are moral divides, however, we can see how our opponents might be simultaneously well-informed; intelligent; moral and genuine - it's just that their moral values are slightly different from our own.

The key difference is that while it is possible to be more intelligent than someone, it is impossible to be "more moral": thus intellectual debates can have an absolute "winner"; moral debates cannot.

American politics have in recent years become increasingly polarized, with conservative republicans clustered on the far right and liberal democrats on the left. The realization that our political affiliations stem from our individual moral sensitivities (as Jonathan Haidt argues convincingly) might go a long way in ending this era of mutual incomprehension.

Moreover, morality is at least partially heritable. Very loosely speaking, this means there are "liberal" and "conservative" genes, which may be influencing the stance that individual people (like yourself for example) have taken on issues like abortion, preemptive war, and economic policies. This means that, if you are willing to accept that homosexuality is "not a choice" - as most liberals are - then you might have to accept the same argument from someone who votes Cheney / Palin in 2012.

A recognition of these facts would, I believe, go a long way in easing the polarization of American politics; treating such disagreements as intellectual ones too easily leads to shouting matches, because they are, in fact, about moral values; they are disagreements between people who place a varying emphasis on the rights of the unborn versus the those of the living; security versus pacifism; economic freedom versus economic equality. There are no "right" or "wrong" answers to these moral questions, simply because their solutions are, inevitably, moral compromises.

Thus, many of these debates are analogous to a disagreement over the color of a shirt between people who are genuinely "seeing" a different color when they look at it. So the conversation is only productive if the parties involved can understand the fundamental reason why the disagreement is taking place; they must first agree that: yes, they are viewing the same object; and no, neither one of them is lying; and yes, that they actually are seeing different colors when they look at the shirt.

At this point you might ask "if some of our most fundamental disagreements are moral ones, and yet we are unable to "see the same color blue", how can these issues ever be resolved? Are we forced to merely agree to disagree?"

Fortunately, I don't think so: just as we can use science to determine the actual color of the shirt (by measuring the frequencies of light that it reflects), we can use it to resolve moral disagreements. Basically, we have to shift the focus of our debates from moral issues that appear to be intellectual, to genuinely intellectual issues. As Steven Pinker, in his (excellent) book The Blank Slate, points out:

"...biological facts are beginning to box in plausible political philosophies. The belief on the left that human nature can be changed at will, and the belief on the right that morality rests on God's endowing us with an immaterial soul, are becoming rearguard struggles against the juggernaut of science."