Overwhelming Evidence

June 18, 2007

I came across a fascinating post at an Intelligent Design Creationism blog, called “micro vs. macro evolution – where to draw the line?”

Given the source, and the title, I immediately chuckled. Of course, this is a very difficult question for those whose religious beliefs lead them to reject the overwhelming evidence in support universal common descent. I’m going to offer some excerpts from this post in order to point out a few common themes among conservative Christians and their relationship with Intelligent Design proponents (most of the latter fall into the former category, but many Young Earth Creationist Christians have problems with the ID guys). First sentence:

Like many Christians (and unlike many Intelligent Design purists), I believe that Darwinian evolution cannot possibly account for the diversity of KINDS of animals.

Notice immediately the language of “belief.” There is no appeal here to evidence for a point of view, as this poster isn’t even trying to pose as interested in the science of it all. Also, the concept of “kinds” is highly ambiguous. What makes mammals a different kind from birds? Where’s the line between birds and reptiles (of which they are actually a subset)? Where do you stick a platypus, or an archaeopteryx?

I believe that our designer designed each KIND independently. But, as I mentioned in a previous blog post, it’s clear the designer recycled designs in a pattern roughly parallel to the evolutionists’ discredited “tree of life.” And at this point I have to make an unpleasant conceit to godless evolutionists: the designs of many parts of our body appear to be modified versions of those used in the design of apes. Yes, these smelly, dirty, brutish animals served as a launching point for our design and, though we certainly didn’t descend from them, we have a certain designerly connection to them, much as Windows Vista does to Windows Millennium Edition.

The adjectives are quite fun. Godless evolutionists may certainly describe Dawkins and PZ Myers, but it would be a hard term to fit to Francis Collins. There are probably more religious people who think the theory of evolution is well-proven then there are non-religious people, simply because there are more of the religious, at least in this country.

And of course, animals are “smelly, dirty, brutish” but we could never, ever have descended from them. What evidence is offered as refutation? None. And of course, there is no indication that the writer has considered the overwhelming evidence for universal common descent, be it fossil or genetic. It’s all about what one chooses to believe. In this sense, many believers are much more postmodern than the evolutionists who they think lack a belief in truth. Fascinating.

Then, the poster goes on to say that there is diversity within a population, and that certain traits will be selected for, thereby ceding that evolution occurs on certain scales. So why can’t it account for new “kinds” (whatever those are)?

But it is micro-evolution, and never strays outside the boundary of a KIND. A dog cannot evolve into a cat. In ten million years, I contend, a dog’s descendants will still be recognizable dogs. Indeed, even after a billion years of microevolution, a dog’s descendants will still be something other than cats.

This is silly. If change occurs, then over more time, you have more change. Now of course evolutionary biologists would never claim that a dog would turn into a cat. What they do note is that if at some point in those ten million years you have two populations of dogs that are separated for a period of time, by geography or habits or any other factor that prevents interbreeding, those populations will diverge over time. That’s speciation. And that is considered by many to be the dividing point between micro- and macroevolution. Natural selection does not pretend to predict a dog will become a cat, but to explain that dogs and cats at some point diverged from some common ancestor that had biological similarities to both. The prediction made is that any two other groups separated for a period of time will eventually diverge as well.

But where do we draw the line between kinds, between microevolution and macroevolution? Can a donkey be bred from a horse? Can an alpaca be bred from a camel? Can a tiger be bred from a lion? These all may sound in some way ridiculous, but all of these animal pairs can interbreed, which suggests that they may be of the same kind. Where things can get tricky is when the hybrid born of the mating is itself sterile. Does this mean we’ve crossed a line between kinds, and found the limits of what evolution can change?

These cases of species that are close enough to interbreed but not produce fertile offspring are excellent examples of the fluid nature of biological change. Tigers and lions can produce offspring because they diverged recently enough that they have yet to accumulate the level of genetic difference necessary to prevent all reproduction. However, they have diverged enough to be both noticeably different (unlike species that we humans can’t tell apart with our naked eyes) and noticeably incapable of producing fertile offspring (unlike some species of songbird that while they do not reproduce together in the wild for behavioral reasons, are still physically capable of doing so). Again, an excellent example of speciation and evolution at work, breaking down the idea that each “kind” was created in a perfect, separate form.

I myself have no particular problem with a theory suggesting that all cats are descendant from a common ancestor. I’d even concede that all birds share a common ancestor – from hummingbirds to ostriches. Given enough time, I could see that change happening – it’s just a few orders of magnitude beyond the flexibility humans have brought to the domestic dog. Some quasi-evolutionists even allow for all of Primates (soulless monkeys and apes lumped together with humans) to have descended from a single designed ancestor. I myself could never believe such a thing, since I find it revolting to think my ancestors might have been animals.

Instead of the argument from personal incredulity, you get the argument from personal revulsion. Methinks this blogger has too high a view of humans and too low a view of animals. Biologically speaking, that is.

Some Intelligent Design proponents such as Michael Behe go so far as to say that yes, all species evolved from a common ancestor. They’ve been exposed to the evidence enough to know that arguing against this well-proven fact is simply impossible. However, to maintain some “proof” of an involved God from the physical world (pure faith is the enemy) they take their criticism to the level of evolutionary mechanisms. This critique still fails, but is substantially more subtle than run-of-the-mill Creationism, and has enough pseudoscientific sounding jargon backing it up to fool the scientifically uneducated market they’re aiming at: America’s conservative Christians.

And then you get tension between Christians who believe what they believe because it feels right (and/or it jives with their relatively unscrupulous reading of Scripture) and those Christians who are trying to make a (in their view) scientific argument for believing something. But this blogger talks about the revulsion that rely underlies all of Creationism, including the Intelligent Design movement: many simply reject the proposition that God is not necessary to account for the origin of the human species because it is religiously unpalatable. These rejectionists laud people like Behe (look, he says random mutation doesn’t work!) or Collins (look, a scientist who still believes in God) or Einstein (look, a guy who misleadingly uses the word “God” when talking about nature, thereby confirming our hopes that he’s on our side) to support what they believe by faith, and reject the parts they dislike.

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The Epitomal Transhumanist

January 19, 2007

This video of Ray Kurzweil (about 23 minutes long) is an excerpt from an annual seminar called TED Talks (for Technology, Entertainment and Design) that features leaders from a variety of fields. While most of the talks seem to focus on society or technology, the perspectives are quite broad: Al Gore, Rick Warren, Daniel Dennett, Bono, and Richard Dawkins have all graced its stage in recent years.

Ray Kurzweil is a prominent transhumanist, and has one of the most optimistic views of technology possible. One of his more recent books is The Singularity is Near, which describes his view that not only is the eventual surpassing of humanity by artificial intelligence inevitable, it is also nearer than we think. In Kurzweil’s view this process will include the merging of our own personal consciousness with the advanced capabilities of computers to eventually be able to process more quickly, analyze more astutely, retrieve data more accurately, and so on. In Kurzweil’s view, what truly distinguishes homo sapiens is not our current biological status, history, or accomplishments, but our impetus to transcend our limitations. Technology merely offers us a new vehicle for our transcendence.

Regardless of whether you embrace his views wholeheartedly (they seem a bit optimistic even for me) or you feel a shiver of terror or silent mockery slipping down your Luddite spine, Kurzweil’s thought should be examined because of his influence. He’s a successful inventor and author, and a prominent figure among futurists and transhumanists. Here’s a summary of sorts of Kurzweil’s TED talk:

Can we predict the future? While certain specifics of technological progress are very hard to predict, overall trends are predictable, and they’re also exponential. Growth in one technology enables and promotes growth in another technology. 50 years to adopt telephones, 8 years to adopt cell phones. TV took decades, but new technologies- like the internet- have taken off much faster.

Kurzweil then makes an analogy to biological evolution. The evolution of genetic material (DNA/RNA) took billions of years, but once certain genes were in place (or the common “tool-kit,” as evo-devo would put it) more rapid (~10 million years) change, like the Cambrian “explosion” (a term that is disliked in many circles) can occur. But as the first technology-creating species, our culture has allowed us to “evolve” on a level that is exponential in comparison to biological evolution (which is one reason we have a hard time understanding evolutionary time scales).

It took tens of thousands of years to develop agriculture, then thousands to move to more centralized forms of government (those two are arguably related, but the direction of causality is disputed), civilization led to quicker technological development, etc. The last 500 years of technological growth were incredible, but the last century has been even more impressive- bringing us widely available automobiles, radios, TVs, airplanes, medical technology, computers, Internet, not to mention space flight and an incredible plethora of new weapons systems with which to butcher each other.

This emphasis on technological development as an exponential process is a major theme of Kurzweil’s work. But, he points out, people always begin doubting when exponential growth for future technology is predicted. This growth is a result of

“worldwide chaotic behavior.. You would think it would be a very erratic process, yet you have a very smooth outcome… Just as we can’t predict what one molecule in a gas will do- it’s hopeless to predict a single molecule- yet we can predict the properties of the whole gas using thermodynamics very accurately. It’s the same thing here- we can’t predict any particular product, but the result of this whole worldwide chaotic, unpredictable activity of competition in the evolutionary process of technology is very predictable, and we can predict these trends very far into the future.”

Kurzweil also talks about the suboptimal nature of much human biology (so much for perfect design). For example, our metabolism, which leads us to hold onto every calorie, is a throwback to our hunter-gatherer days and is something that we might like to modify to prevent obesity in developed nations. And another problem, which seems to be Kurzweil’s main fascination: “Long life spans (as in more than 30) weren’t selected for.”

While some of his examples are sketchier than others, the idea of an engineered erythrocyte (red blood cell) that could increase oxygen capacity greatly is particular interesting. In my view, Kurzweil has a tendency to exaggerate about some possibilities, but then again, exponential growth will always appear as an exaggeration to those in a linear-growth mindset.

I think more important than any individual predictions about technological progress that Kurzweil makes (like reverse-engineering the brain by 2020), his main point stands: the progress of technology throughout history has been accelerating. The main question tends to be whether we’ll be able to harness these technologies to make life more certain, more pleasurable, more equitable, more eco-friendly, and more connected (and therefore more meaningful on some level) or to just wipe each other off the planet.


The Big Bad Reductionist

January 15, 2007

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I picked up a copy of Richard Dawkins’ The Blind Watchmaker used for about $3 the other day. I like to think that the person who sold the book did so because this paperback addition has a horrendously ugly cover, not because of the content.

I’ve been interested in reading The Blind Watchmaker for some time, as it seems to be the most direct reponse to the “argument from design” out there. Of course, my father, who teaches design as it applies to human art and is therefore rather convinced by this apologetic, is the most vocal proponent I know, but I hear jabs about watches found on walking paths and Boeing 747’s found in deserts fairly often from others as well.

Dawkins’ answer is, no surprise, that the watchmaker that designed the complexity of life is a blind one: the “designer” is Darwinian evolution. For now I’ve only gotten to page 13, where he’s currently defending reductionism (or more specifically, the hierarchical variety):

For those that like ‘ism’ sorts of names, the aptest name for my approach to understanding how things work is probably ‘hierarchical reductionism’. If you read trendy intellectual magazines, you may have noticed that ‘reductionism’ is one of those things, like sin, that is only mentioned by people who are against it. To call oneself a reductionist will sound, in some circles, a bit like admitting to eating babies. But, just as nobody actually eats babies, so nobody is really a reductionist in any sense worth being against. The nonexistent reductionist–the sort that everybody against, but who exists only in their imaginations–tries to explain complicated things directly in terms of the smallest parts, even, in some extreme versions of the myth, as the sum of the parts! The hierarchical reductionist, on the other hand, explains a complex entity at any particular level in the hierarchy of organization, in terms of entities only one level down the hierarchy; entities which, themselves, are likely to be complex enough to need further reducing to their own component parts; and so on. It goes without say–though the mythical, baby-eating reductionist is reputed to deny this–that the kinds of explanations which are suitable at high levels in the hierarchy are quite different from the kinds of explanations which are suitable at lower levels… Reductionism, in this sense, is just another name for an honest desire to understand how things work.

On a similar note, here’s an article on PubMed about “Reductionism and Antireductionism,” and another on the “Search for organizing principles: understanding in systems biology.” (The latter seems to advocate principles of holism as opposed to reductionism as a means for understanding complex systems.)

Over at Meta-Library, a writer highlights a quote by Francis Crick (co-discoverer of the structure of DNA), that “The ultimate aim of the modern movement in biology is in fact to explain all biology in terms of physics and chemistry.” The writer (evidently a Christian, a dualist, and not a big fan of reductionism based on his disagreements with Dawkins and Wilson) asks three questions to consider whether Crick’s attempt to reduce biology to physics and chemistry has or ever will succeed. The three questions are as follows:

  1. do the laws of physics and chemistry apply to the atoms and molecules of living things?
  2. are the interactions of atoms and molecules according to physics and chemistry sufficient to account for biological phenomena, or are other kinds of interaction needed?
  3. can biological theories be deduced logically from the theories of physics and chemistry?

The author, a certain Dr. Southgate, answers yes to the first two and no to the last. I think the answer appears to be yes to all three, or at least that yes, these are possible to be deduced– not that we necessarily already have.

Today, during the opening lecture of my physics course, the professor made the statement that electromagnetic forces are what make everything work, at least on the scale that we normally experience–the biological scale (he noted the existence of nuclear forces, which we don’t often experience clearly firsthand). If it weren’t for those electromagnetic forces, gravity would pull a dropped ball straight through the earth because none of the particles would hold together. None of chemistry would work (or at least be the same) if the nature of electromagnetic reactions were different, and biochemistry, biology, ecology, and on and on would each in turn be different.

While all the principles of biology–such as a thorough understanding of human consciousness or religious belief–may not be fully reducible yet, I see no epistemic or ontological limitations that should limit our pursuit of reductionism. So Dr. Southgate would have to justify his answer of “no” to statement number three. Reductionism works; postulating that it will fail in the future because it might explain realms normally coveted by other realms, like psychology or theology- requires an explanation.


You Are Here (The Circle of Phylogenetics)

November 26, 2006

Phylogenetics is the study of the relatedness of organisms. In other words, scientists look at physical traits (morphology) and (more recently) DNA sequences to determine which organisms have more in common that others. Even if you’ve never heard of phylogenetic taxonomy before, you’re already familiar with some basic separations, such as between animals and plants. The Tree of Life has some nice illustrations, but I thought this circular phylogenetic tree was especially cool:

wholecircle

This circular tree, which was published in Science, Shows relationships between representatives of all species on Earth. It was developed by David M. Hillis, Derrick Zwickl, and Robin Gutell at the University of Texas. As they state on their website (where the full pdf file is available- a really cool thing to zoom in and out on!) the tree is:

“an analysis of small subunit rRNA sequences sampled from about 3,000 species from throughout the Tree of Life. The species were chosen based on their availability, but we attempted to include most of the major groups, sampled very roughly in proportion to the number of known species in each group (although many groups remain over- or under-represented). The number of species represented is approximately the square-root of the number of species thought to exist on Earth (i.e., three thousand out of an estimated nine million species), or about 0.18% of the 1.7 million species that have been formally described and named.”

Here’s a closeup of the Animals section:
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The arrow below points to humans:

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And one final zoom in:

This reminds me of a quote from Tim Rice that ended up in my Developmental Biology textbook:

“It’s the circle of life, and it moves us all.”


Concerning the Beast Folk

November 22, 2006

On a recent visit to Barnes & Noble (this literary addiction is getting rather expensive) I browsed through a stack of compilations of novels by famous authors. One caught my eye: a collection of works by H.G. Wells. It includes the Time Machine, War of the Worlds, and The Island of Dr. Moreau, all of which I’ve been meaning to read, so I found it a new, loving home–my bookshelf.

 

The Island of Dr. Moreau got inexplicably bumped to the top of my reading queue, probably because I was craving something fictional. I saw the movie adaptation some years ago, and had vague memories of it being creepy, scary and disgusting.

 

The basic premise is that Prendick, passenger on a sea voyage, is shipwrecked on an island occupied by the namesake physiologist and his assistant. The only other residents of the island, as the narrator eventually discovers, are monstrous human/animal hybrids.

 

Dr. Moreau was a prominent physiologist in London who was eventually driven away from respectable society by his methods, including his disregard for the pain caused by his experiments. Dr. Moreau moved shop to his island, where he was free to take all manner of beast and shape them into human form.

 

While the science is assuredly outdated in ways, Dr. Moreau’s reality has a potential to become ours. Whole segments of one embryo can be grafted onto another of a different species during development, and many of the results can be both surprisingly revolting and survivable.

 

Our pursuit of cures for genetic diseases in humans will inevitably lead to an ability to alter specific genes for the sake of improvements, not just treatments. (Some, such as members of the transhumanist movement, openly advocate improving the human species in this way.) Surely someone will also realize the benefit of inserting genes for the production of human insulin, antibodies, or blood into a primate. Or what about using animals to grow replacement human organs?

 

Not many are openly calling for the creation of more grotesque human/animal chimeras, but as the ability to perform such experiments becomes more diffuse, it is nearly inevitable that someone will eventually attempt it. So we are left with the question of how we will regard these creations. Fully animal? Partly human?

 

For now, I’ll leave you with some rather disturbing diatribes by Dr. Moreau:

“So long as visible or audible pain turns you sick, so long as your own pains drive you, so long as pain underlies your propositions about sin, so long, I tell you, you are an animal, thinking a little less obscurely what an animal feels.”

“Then I am a religious man, Prendick, as every sane man must be. It may be I fancy I have seen more of the ways of this world’s Maker than you—for I have sought his laws, in my way, all my life. While you, I understand, have been collecting butterflies. And I tell you, pleasure and pain have nothing to do with heaven or hell. Pleasure and pain—Bah! What is your theologian’s ecstasy but Mahomet’s houri in the dark? This store which men and women set on pleasure and pain, Prendick, is the mark of the beast upon them, the mark of the beast from which they came.”

“To this day I have never troubled about the ethics of the matter. The study of Nature makes a man at last as remorseless as Nature.”

For the record, I don’t recommend Moreau’s ethics or theology. But bravo to Mr. Wells: good novel, nice concept, and interesting dilemmas. I think I’ll have to watch that movie again and see what I think now.


Gentlemen, we can rebuild them. We have the technology.

November 16, 2006

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Well, not exactly. But if we can sequence the human genome (in record time and underbudget, thanks Mr. Collins), why not the Neanderthals genome too?

There have been some big potential holdups. First, there’s the problem that they’re extinct. And then the fact that genomes start degrading right away. And that 95% of the DNA recovered from Neanderthal bones is bacterial DNA. And most Neanderthal bones that have been recovered are hopelessly contaminated by the DNA of the humans who found them.

But new advances in technology appear poised to overcome what used to be seen as insurmountable obstacles (a recurring theme in the biological sciences). The New York Times reports that scientists at the Max Planck Institute in Germany are using a new technique that can combine small fragments of ancient DNA (usually under 100 base pairs in length) into complete genomes.

The process filters out bacterial DNA and slowly pieces together the larger genome. It’s been used on ancient cave bears and mammoths, but the application to Neanderthals would shed light on a particularly controversial area of scientific investigation; whether Neanderthals are direct human ancestors or merely a related line that died off (or that we out-competed or killed off).

Sequencing the Neanderthal genome (which at ‘first glance’ is 99.5% identical to human, whereas chimpanzees are at least 95% identical genetically) will give us better evidence on the question of whether humans crossbred with Homo neanderthalensis, picking up important genes along the way, or simply displaced Neanderthals in Europe around 35,000 years ago. While most scientists seem to agree that there is no hard evidence for crossbreeding, not everyone agrees.

Some scientists have recently asserted (in the Proceedings of the National Academy of the Sciences) that humans picked up an important gene (microcephalin, MCPH1) necessary for brain development from Neanderthals.

One reason this research will be so fascinating to follow is that the relation of Homo sapiens (us) to Homo neanderthalensis (them) is anything but certain. Neanderthals (see Wikipedia) had tools, likely had language (their hyoid bone was nearly identical to ours), buried their dead, constructed complex shelters, controlled fire, and possibly even made rudimentary musical instruments.

So what we Neanderthals really like? Only time (and good genome sequencing technology) will tell.