Archive for the ‘Uncategorized’ category

Flushing a random tube #2

August 21, 2009

Continuing with posting random notes focusing on science, I’ve looked around for some interesting articles dealing with evolution with free online access.  Here’s a few to start:

First, the 1972 Eldredge and Gould Punctuated Equilibria article, available here in pdf format. This is the paper where Eldredge and Gould first describe the concept.  For a more basic explanation of Punctuated Equilibria, talk.origins has a decent overview on the subject (available here).

Continuing with Gould, here’s his article titled “The Validation of Continental Drift”, focusing on some of the developments leading up to the modern theory of plate tectonics.  Good stuff! 

If you’re interested in origins, the 1858 Darwin and Wallace evolution paper is well worth checking out.  If you’ve read the Origin of Species, you owe your sanity to this paper presentation, which (along with Wallace initially contacting Darwin) led to the publication of Darwin’s “short abstract” that is the Origin of SpeciesHere’s the paper presentation from the University of Maryland website.

A final link of interest for this posting, the NCSE has a decent overview of all the major court cases dealing with evolution or anti-evolution movements.  If you’re interested in this topic, their site has an entire section focusing on it.  Available here.

Flushing a Random Tube #1

August 19, 2009

Trying a new approach on here.  I’m going to keep doing my more intense posts on a regular basis (ie longer posts focusing on one thing in detail), but also try to post other material of interest in shorter posts on a daily (or at least almost daily) basis, just to keep things interesting.  Today, as a result of inspiration from Stephen Colbert’s satirical wiki page, I’m flushing some random tubes, or looking around the internet for sites of interest.

First site in line is from Access Research Network, one of the major ID sites on the internet.  This is the ID Arts page.  From the page itself (available here):

“Our worldview impacts all areas of life including the arts. The arts also reflect philosophical and cultural trends in human societies. If philosophical and scientific concepts of intelligent design (ID) are valid, we believe they will both inspire, and be reflected in, our art, music, literature and film.”

So as we can see, ID is a social movement after all, regardless of the science.  This social aspect is reflected in the Wedge Document (although ARN is not part of the Discovery Institute, they are closely linked)(available here):

Discovery Institute’s Center for the Renewal of Science and Culture seeks nothing less than the overthrow of materialism and its cultural legacies. Bringing together leading scholars from the natural sciences and those from the humanities and social sciences, the Center explores how new developments in biology, physics and cognitive science raise serious doubts about scientific materialism and have re-opened the case for a broadly theistic understanding of nature. The Center awards fellowships for original research, holds conferences, and briefs policymakers about the opportunities for life after materialism.”

Now, stepping away from the Intelligent Movement, I want to highlight an extremely well-done paleontology website, the Oceans of Kansas project (available here).  If you’re interested in Mosasaurs and other aquatic reptiles from the Mesozoic (or paleontology in general), this site is well-worth checking out.

Also, in the world of Climate Change, the Hughen Falconer thing seems to be resolved.  In a comment on Chris Colose’s blog, it appears that someone sent an email to the people compiling the list asking to be added to it.  The people compiling the list apparently didn’t care enough to check the background of the the person in question though; apparently verifying a person’s credentials is not important.  Here’s the relevant part of the comment (available here; August 19th 2009 comment):

Further to this, I received an email reply from the site administrator and a person calling himself Hughen Falconer has had himself added via an email sent from a yahoo.com email address on 29th July.”

At least there’s some resolution there now; this “Hughen Falconer” guy seems like a hoaxter.

A Simple Truth

August 17, 2009

I put this post together in response to a conversation I got involved in dealing with science, pseudoscience, and religion.  Here it is in it’s unpolished, angry, and raw form:

What’s so terrifying about evolution?

While evolution is generally accepted among scientists, the public perception of evolutionary theory is mixed.  Many people perceive the existence of a “controversy” between advocates and opponents of evolution.  Some view evolution as an atheistic godless project that seeks to destroy all that is sacred to them.  Others sincerely believe that the science behind evolution is truly lacking, that competing ideas such as Intelligent Design or Creation Science (which are pseudoscientific in nature) are actually valid alternative ideas. 

Lost in the wings of most public engagements of evolution lies the following line of inquiry:

“What if evolution is real? What does this imply for our destiny?”

Let’s consider the question for a moment.  The question in question cuts directly to the root of the human identity.  If evolutionary theory is even partially correct, then it has profound implications for our species.  Daniel Dennett (1995) describes the theoretical framework in question as a “universal acid” that intrinsically alters all that it touches.  Evolution is indeed such an acid.  When looking at ourselves as a species, what do we see? Are we somehow “above” nature, and immune to it’s carnal struggles, or are we a part of nature, subject to the rules that govern the natural world?

The most cutting aspect of evolutionary theory is also perhaps the most overlooked.   Let’s step away from transitional features, hox genes, phylogenies, radiometric dating techniques, and the plethora of other scientific lines of inquiry contributing to the study of evolution and deep time.  We’re looking for something much simpler, yet also much deeper.

This Simple Truth is stunningly obvious when considered.  If humans are the product of evolution, then our fate is intrinsically linked to that of our planet.  You may be preparing to question the validity of this statement, perhaps noting a possible re-definition with religious terms (perhaps a “Young-Earth-Creationist-friendly” re-statement of it).  However, at least to the depth necessary for this inquiry (although I am not an expert on theology or comparative religions), I feel that my statement holds true.  The God of the Young-Earth Creationists is one that can and does intervene often throughout Earth’s history, creating a global flood responsible for the fossil record and also able to remove the waters necessary for this flood (note that I am not in support of Flood Geology, a concept first developed by George McCready Price and later championed  by Whitcomb and Morris in The Genesis Flood; the scientific validity of Flood Geology is notably lacking).  This God could easily intervene if the human race leads itself towards the brink of extinction through nuclear proliferation, environmental destruction, global warming, or some other threat. On a slightly different note, Intelligent Design, with its strikingly anonymous designer, could present a similar situation.  Does the Magical Mystery Man (my preferred name for the Intelligent Designer, since we are given no name) intervene at the gaps in the fossil record, or after extinction events?  When does intelligent design take place?  And is the Magical Mystery Man able to intervene in other aspects of the universe?  We may never know.

However, if one accepts the validity of evolution, then we are on our own here.  I’m not claiming that evolution leads to atheism or agnosticism.  There are many theistic evolutionists, such as Roman Catholic scientist Kenneth Miller.  Miller’s 1999 book “Finding Darwin’s God: A Scientist’s Search for Common Ground Between God and Evolution” suggests that religious belief and an acceptance of evolution are not mutually exclusive.  Setting aside a discussion of whether evolution leads to atheism or not (as demonstrated, it need not), let us return to our discussion.  Evolutionary theory places us as a part of nature.  Our fate and the fate of the world around us is inextricably linked.  If we destroy the world in which we live, we can likely expect no divine intervention, no saving grace from above.  From a Christian perspective, God gave us free will, and is allowing us to exercise it (but expects us to face the consequences of our actions).  From an atheistic one, there is no God, and  besides, why would a non-existent entity intervene to save us from ourselves?

The heritage of our evolutionary history is visible on a global scale.  Like all organisms, everything we do impacts the world around us.  How can we be so naïve to think that we are invincible?  We have destroyed countless species in our own lust for growth, development, and opulence.  Judging from the fossil record, it is likely that our actions will catch up with us eventually.  Life is a precious thing, and the fossil record shows us that it can easily be extinguished (such as during the mass extinctions at the end of the Permian, Ordovician, and Devonian Periods, among others).  Are we on the path towards our own extinction? 

If evolution happens, then what about other “controversial” ideas such as climate change?  Are humans really able to alter global temperatures on a noticeable scale?  After all, there are lists of scientists who seem reputable that oppose climate change.  However, these lists are often relatively disreputable.  For example, a recent one lists a “Hughen Falconer” among its signees (as noted on Chris Colose’s blog.  Click here).  This “Hughen Falconer” appears to be none other than Hugh Falconer, the Victorian paleontologist.  Of course, nobody was talking about global warming in Falconer’s day!  The general scientific consensus tends to be a “positive” one: humans have had a noticeable impact on climate change.  This makes sense.  If one looks at the amount of energy used by people on a global scale per day, it is absolutely astounding.  Our mining ventures can easily destroy entire mountains and replace them with lakes (see LeCain 2009 [for more on this book, see here] for more on open pit mining); the human hunger for metals such as copper for industrialization has had huge environmental costs.  Why doubt the impact of other human activities?  Lowly stromatolites (Cyanobacteria, or “algae) were able to forever alter Earth’s early atmosphere.  Why wouldn’t humans be capable of causing alterations of a similar scale.  According to most reputable climatologists, the verdict is in.  Humans have accelerated global warming.

If the implications of evolution and climate change are so profound, then why do so many people question the validity of these ideas?  I have implied that both evolution and climate change are well established scientific concepts. But if scientists accept them, then why does the general public often perceive them to be controversial ideas? Why evolution and climate change instead of quantum physics and advanced calculus?  Do the scientists have something to hide?

Luckily for scientists, it appears that they aren’t hiding anything.  Deniers of global warming or evolution often use out-dated or false arguments to further their point.  For example, in his book “Evolution: The Fossils Say No!”, Young Earth Creationist Duane T. Gish states that if we had “five or six” transitional forms from the evolutionary transition between fish and amphibians, it would be sufficient to prove evolution (52).  However, Gish was apparently not familiar with Icthyostega, Acanthostega, Tiktaalik, Panderichthys, Eusthenopteron, or other “transitional forms” (I will use the old term, which can be translated loosely to an organism that showcases lots of transitional features).  Even if he was, it he would likely make the same argument.  Scientific credibility is often not important to these people. 

What is important is public perception.  Raise objections that the average person, with little background in the subject in question, would see as reasonable.  Appeal to his sense of reason and fairness.   Show a list of scientists who doubt climate change or evolution, and claim that that list represents a sizeable portion of reputable scientists.  It’s ok if they are people with PhDs in Business and no scientific credentials, or have been dead for 200 years, or have little or no credibility within their own field of study.  You have their name on a list of people that deny climate change or evolution.  You can claim that they’re being oppressed for their views. Remind your reader that this is a democratic society, and that this oppression is unfair and un-American.  Heck, you can even appeal to your reader’s sense of patriotism if you want! Show your reader surveys of the American public that illustrate public doubts about evolution or climate change against surveys of scientists who overwhelmingly accept evolution or climate change, and then ask “why should the minority govern the majority?”

But most important of all, don’t worry about the facts.  Forget the fact that science is not a democracy.  Forget that science is governed by cold, hard data and not feelings, sympathy, and fairness.  Forget  (or rather exploit the fact) that the general public knows little about science, and do not attempt to educate the public.  Rather, use this lack of knowledge as a weapon to further your own goals.  Forget to try to publish your ideas in reputable journals, and focus on winning public opinion rather than scientific credibility.

But judging from the implications of evolution and climate change, should we let you succeed?  I say NO.  We should strive to educate the public about the nature of science, how it is done, the real meaning of the word “theory” in science (hint: it doesn’t mean “an unsupported guess”!!).  Point out the unscientific nature of religious attacks on evolution, but remain respectful of religion. Critically examine lists of “scientists who accept Creationism”, or “scientists who doubt climate change”, or “scientists who have doubts about Darwin”.  But most importantly, we must strive to expose pseudoscience and misinformation campaigns for what they are:

Bullshit.

The cards are on the table, and the stakes are high.  We can embrace our place within nature and fight the threats to our existence, or we can deny it, and blindly hope for the Magic Mystery Man (our old friend the “intelligent designer) to ride in and save us.  What’s it going to be?

Works Cited:
Dennett, D.  Darwin’s Dangerous Idea: Evolution and the Meanings of Life. Simon & Schuster Paperbacks, New York, 1995
Gish, DT.  Evolution: The Fossils Say No!. Creation-Life Publishers, San Diego, 1979.
LeCain, T.  Mass Destruction: The Men and giant Mines That Wired America and Scarred the Planet.  Rutgers University Press, New Brunswick, 2009.
Miller, K.  Finding Darwin’s God: A Scientist’s Search for Common Ground Between God and Evolution. HarpersCollins Publishers, New York, 1999

Also, thanks to everyone involved in organizing The Giants Shoulders, a monthy collection of posts focusing on history of science.  My Hugh Falconer post has been included in this month’s edition.  For this month’s edition, click here.

Would Thomas Jefferson support Intelligent Design?

July 22, 2009

According to a recent article (here) by Stephen Meyer (of The Discovery Institute’s Center for Science and Culture), Thomas Jefferson is claimed as an advocate of Intelligent Design (were he alive today).  However, the article has some relatively weak points that underly it’s basic claims.  First, let’s not ignore the obvious fact that Jefferson died in 1826 (July 4th), long before Darwin and Wallace first published their evolutionary thoughts.   So Jefferson is claimed as an opponent of Darwin, even though he was never exposed to Darwin’s theory of Natural Selection.   Meyer places deep emphasis on Jefferson’s opposition to “materialistic theories of evolution” that pre-dated Darwin:

“In 1823, when materialist evolutionary ideas had long been circulating, Jefferson wrote to John Adams and insisted that the scientific evidence of design in nature was clear: “I hold (without appeal to revelation) that when we take a view of the Universe, in its parts general or particular, it is impossible for the human mind not to perceive and feel a conviction of design, consummate skill, and indefinite power in every atom of its composition.’’ It was on empirical grounds, not religious ones, that he took this view.” (from Meyer article linked above)

So Jefferson rejected pre-Darwinian theories of evolution on empirical grounds.  This makes sense; pre-Darwinian models of evolution were often weak in nature, and generally deeply flawed.  Pre-Darwinian theories of evolution were often deep within the realm of pseudoscience, with no real mechanism to hold them up under scrutiny.  Lamarck’s work is remembered by most people as a failed alternative to Darwinian theory that preceded Darwinian theory.  Here’s a good description of Lamarck’s theoretical structure:

What was the mechanism for evolution? “Lamarckism” or “Lamarckianism” is now often used in a rather derogatory sense to refer to the theory that acquired traits can be inherited. What Lamarck actually believed was more complex: organisms are not passively altered by their environment, as his colleague Geoffroy Saint-Hilaire thought. Instead, a change in the environment causes changes in the needs of organisms living in that environment, which in turn causes changes in their behavior. Altered behavior leads to greater or lesser use of a given structure or organ; use would cause the structure to increase in size over several generations, whereas disuse would cause it to shrink or even disappear. This rule — that use or disuse causes structures to enlarge or shrink — Lamarck called the “First Law” in his book Philosophie zoologique. Lamarck’s “Second Law” stated that all such changes were heritable. The result of these laws was the continuous, gradual change of all organisms, as they became adapted to their environments; the physiological needs of organisms, created by their interactions with the environment, drive Lamarckian evolution.” (From here)

However, as sophisticated as Lamarck’s model was, he failed to win the support of many scientists of his period.  While Lamarck presented the first truly well-known scientific model of evolution, it would have been entirely possible for someone with a scientific background to reject it.  In fact, many scientists did, and with the advent of Natural Selection, Lamarckism was relegated to the intellectual dustbin in most societies.

What was extremely popular during Jefferson’s lifetime was popular pseudoscientific theories of evolution.  One of the most well-known of these publications is Robert Chambers’ Vestiges of the Natural History of Creation (published after Jefferson’s death, however.  I use it here for sake of familiarity). In any case, concepts of evolution circulating at the time of Jefferson were weak enough to be rejected outright by someone with a scientific background (as Jefferson had).

Let’s go back to the Stephen Meyer article again.  Here’s another quote from it:

“Contemplating everything from the heavenly bodies down to the creaturely bodies of men and animals, he argued: “It is impossible, I say, for the human mind not to believe that there is, in all this, design, cause and effect, up to an ultimate cause, a fabricator of all things from matter and motion.’’

The “ultimate cause’’ and “fabricator of all things’’ that Jefferson invoked was also responsible for the “design’’ of life’s endlessly diverse forms as well as the manifestly special endowments of human beings. Moreover, because the evidence of “Nature’s God’’ was publicly accessible to all and did not depend upon a special appeal to religious authority, Jefferson believed that it provided a basis in reason for the protection of individual liberty. Thus, the Declaration of Independence asserted that humans are “endowed by their Creator with certain inalienable rights.’’

So now Meyer alludes to Jefferson’s alleged belief that life is “designed”.  Thanks to natural selection (see Richard Dawkins’ The Blind Watchmaker for more on this), science has a way to explain the apparent “design” of life.; natural selection weeds out “bad” “designs” and preserves “good” ones.  Note that I’m not saying that science is atheistic, however.  The big thing about science in its modern form is that it cannot by definition accept or deny supernatural causation as an explanation for observed phenomenon. Put Jefferson in a modern setting, with the full body of scientific knowledge available today, and it is entirely possible that he would embrace evolutionary theory with open arms.  However, dead men can’t speak, so it takes academics such as Stephen Meyer to try to translate their views into modern contexts.  Unfortunately for Meyer, claiming a long-dead person as a supporter of Intelligent Design ( be it Jefferson or Isaac Newton), even though that person died long before Darwin published his first works on natural selection, is misleading.  However, Meyer assures us that Jefferson’s support of Intelligent Design has been vindicated by modern discoveries such as the structure of DNA. 

  I would not be so quick to embrace Jefferson as a supporter of Intelligent Design.  Jefferson had no grasp of the terms of the modern playing field.  He was not exposed to the mountains of evidence that scientists now have amassed in favor of evolution, or to the weakness of “Intelligent Design”, which now stands as pseudoscience.  But even if Jefferson would accept Intelligent Design today, there is one more question to ask: Who cares?  What relevance does a 200-years-dead politician have in a debate over the validity of Intelligent Design?  I could sit here and claim Isaac Newton as an opponent of Einstein’s general relativity until I’m blue in the face.  However, that would not make my argument compelling.  If Intelligent Design is so compelling, why not quote a body of able-minded modern scientists with good reputations as supporters rather than a guy who’s been dead for almost two centuries and had virtually no connection to the modern issues? Seems like a weak strategy to me…

**News Flash** Acceptance of Evolution the Root of Drunken Misadventures Among College Students

July 16, 2009

Just read an article on the Institute for Creation Research’s website, and thought I’d share it on here.  I’ve said many times that anti-evolution movements are often sociopolitical rather than scientific at their base, and this article supports that claim.  According to the article (available here), an acceptance of humanism (which the article implies is deeply connected to an acceptance of evolution) is the cause for society’s ills, such as hedonism, alcoholism, and other miscellaneous evils.  The article also argues that universities are bastions for humanism, thus apparently making college campuses ripe breeding grounds for hedonism.  Let us not be mistaken, however.  The article also makes it clear that religious college students are not as at risk for drunken adventures as other students.  The cause of the problem is placed squarely on the shoulders of humanism and an acceptance of evolution.

Funny; I accept evolution as a valid science, yet I’m not glued to the bottom of a barstool or the rim of a pub toilet.  Oh well.  Can’t fit the stereotypes all the time.  Just keep in mind that this type of scenario is at the base of movements such as the Young Earth Creationist movement.  It’s not really the science that is the problem; it’s the worldview.  If you need me, I’ll be at the pub.

No intelligence allowed?

July 14, 2009

I’d like to start off by wishing everyone a happy Bastille Day. I’m not French, but I am a Rush fan, and this date always reminds me of the Rush song titled “Bastille Day”, with Geddy Lee’s Canadian high-pitched voice singing “there’s no bread, let them eat cake, there’s no end to what they’ll take…”. Anyway, while we’re on the topic of pop culture and media, let’s shift to something more academic in nature. In fact, lets take a look at a recent documentary that criticizes academia for allegedly suppressing advocates of a certain “scientific” theory.

 Those of you who have followed the ID movement closely will already suspect which documentary I’m referring to. To confirm your suspicions, yes, I am referring to Ben Stein’s Expelled. The problems with this film are myriad, and far too vast to be covered in one post. There is, however, a body of work criticizing this film available on the internet (see NCSE’s Expelled Exposed page, available here). As a result, I’ll focus only on a small piece of the documentary, namely it’s misrepresentations of mainstream science and scientists (and I will stop at 1 post with this topic). Let’s start out with one of the biggest quote-mines in the entire film, a misrepresentation of Darwin himself. In the film, Stein quotes from Darwin’s Descent of Man:

With savages, the weak in body or mind are soon eliminated. We civilized men, on the other hand, do our utmost to check the process of elimination. We build asylums for the imbecile, the maimed and the sick, thus the weak members of civilized societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man. Hardly anyone is so ignorant as to allow his worst animals to breed.”

Kind of makes Darwin sound like a racist bastard (please excuse my tone here, but it‘s the best description I can think of), doesn’t it? If you’ve read my other posts on here, or are familiar with Darwin (or a combination of both), this passage should raise some red flags. If you’re familiar with Darwin’s work and quote-mining tactics in general, one question that likely pops up in a case like this is “well where’s the rest of the passage?” This passage made me feel uneasy, and so I referred to my copy of the Descent of Man to find the rest of it. And, lo and behold, it looks like old man Darwin wasn’t so cold after all. Here’s the half of Darwin’s statement that Ben Stein & co neglect to share with us:

“The aid which we feel impelled to give to the helpless is mainly an incendental result of the instinct of sympathy, which was originally acquired as part of the social instincts, but subsequently rendered, in the manner previously indicated, more tender and more widely diffused. Nor could we check our sympathy, even at the urging of hard reason, without deterioration in the noblest part of our nature. The surgeon may harden himself while performing an operation, for he knows that he is acting for the good of his patient; but if we were intentionally to neglect the weak and helpless, it could only be for a contingent benefit, with an overwhelming present evil.” (Darwin 1871 p. 152)

Not surprisingly, reading the passage in its entirety offers a strikingly different perspective on Darwin. Darwin didn’t condone a eugenic-type system to systematically prevent certain members of society from reproducing (as the film suggests). In fact, his actual position was completely opposite, where he implies that this type of move is, at its core, evil. But the filmmakers apparently don’t think that this fact is important. Perhaps they never read the full context of their mined quote, or perhaps their reading comprehension skills suck and they thought that they were accurately portraying Darwin’s position. Maybe they are willfully misrepresenting his position here. Hard to say, but what is obvious is that the credibility of this film is off to a very bad start.

 A second major incident in this film occurs when Stein is talking with Florida State philosopher of science Michael Ruse. Stein asks Ruse about the origin of life, and Ruse suggests one of many ideas on the topic as popular. Those familiar with this area of research will instantly recognize the idea that Ruse is alluding to as one backed strongly by mineralogist Robert Hazen. The framework Ruse alludes to suggests that the early molecules of life formed “on the backs of crystals”. In this process, molecules would have gained structural elements from the crystals themselves. This picture is actually a viable idea, which would explain (among other things) the extreme prevalence of “left-handed” amino acids over “right-handed” ones, and also offer an early source of variation and mutation. However, Stein & co go out of their way to make this idea look ridiculous, cutting to a scene of a fortune teller with a crystal ball. Here, while at least Stein & co aren’t misquoting the idea, they are extremely oversimplifying it to the point that an audience would not be able to grasp the strong points of it. Thus, to an uninitiated audience, this idea would, in fact, seem ridiculous. Looks like a possible political move here; they’re apparently not really out to do good science in this film, but rather to win some cheap points with viewers.

The third major incident I’ll focus on here is Stein’s encounter with Richard Dawkins. This encounter is saved for the end of the film, with Stein confronting Dawkins on his atheist views. Stein proceeds to ask Dawkins whether there could be an intelligent designer. Dawkins utilizes his standard example, with an alien civilization seeding Earth with life. However, the second part of Dawkins’ statement states that the existence of the aliens must be explainable. Stein bites on the first half of the statement, but not the second half. Thus, we see Stein jumping at Dawkins accepting the possibility of some sort of intelligent design, while totally missing the point. Dawkins’ example is simple. Essentially, in the case of intelligent design, there is always the following conundrum, namely “how did the designer come to exist?”. The designer, in Dawkins’ scenario, likely evolved in its own past, thus rendering the ID movement’s critiques of evolution false. But Stein, rather than discussing this fact, just focuses on Dawkins accepting “some types of intelligent design, but not others”. Once again, the makers of Expelled offer an intellectual snow job.

It’s clear from these three examples that Expelled really isn’t about science or accuracy. What matters in the end is not whether any scientific advances have been inspired, but rather the achievement of a political goal. This political goal is a decline in the acceptance of evolutionary theory and all the evils (Nazism, Communism, materialism, humanism, etc.) that certain groups blame on it. Evolution becomes the scapegoat for what is perceived as a larger problem, a society where abortion and divorce and homosexuality run rampant. If the producers of Expelled truly cared about producing a viable intellectual documentary, one would expect that they would have done a better job with the science involved. The fact that they didn’t raises some huge questions about the credibility of the film, but also alludes to its deeper goal.

Works Cited:

Expelled: No Intelligence Allowed (the Ben Stein documentary)

Darwin, C. The Descent of Man and Selection in Relation to Sex, AL Burt Company Publishers, New York, reprint of 2nd Edition.

cladistics

July 6, 2009

Taxonomy can trace its roots back to the work of Linnaeus, who, working from a distinctly Creationist perspective, sought to classify the living world.  However, much has changed since his time.  Darwin published the Origin of Species in 1859, and his work suggested the plausibility of an updated system for classification.  Today, we have such a system.  Cladistic analysis is a newer system of classification (popular in the last 50 years) that has taken hold in recent years.  In fact, it is the basis for the structure of the American Museum of Natural History’s paleontology displays, and is incorporated into the instructive framework of paleontology displays in many other museums.   Let’s take a look at how the system operates.

The taxonomic structure of a cladogram is based on ancestry; a good, monophyletic clade (group sharing same ancestry, see Holtz and Brett-Surman, 92-106) includes only a common ancestor and its descendents.  For example, a Ceratopsian cladogram might include Psittacosaurs and other basal ceratopsians, as well as Protoceratops and more advanced ceratopsians such as Triceratops.  But how is ancestry defined?

Cladistic analysis focuses on shared derived characteristics to identify relationships.  For example, a relatively simple cladogram for humans could include the following traits:

1) presence of a notochord, placing humans within the Chordates.
2) presence of a backbone, thus rendering humans vertebrates.
3) presence of an amniotic sac, rendering humans amniotes.
4) (skipping a bunch here) presence of mammary glands and hair, thus rendering humans mammals
5) presence of a placenta, thus rendering humans placental mammals…

As you can see from the simplified illustration above, cladograms move from basal (or “simple” or “common”) traits towards derived characteristics, such as the placenta. There are more derived characteristics (obviously) defining the human species’ position in a taxonomic hierarchy, but I simplify here for sake of space and in an attempt to prevent complete boredom on the part of a casual reader.  A good cladogram always moves from least specific to most specific with regards to shared characteristics.  If a relationship fails the test of shared basal characteristics, then any apparently “derived” characteristics must be the result of convergent evolution.  Take, for example, birds and bats.  While both fly, birds have feathers and other distinctly archosaurian features, while bats exhibit distinctly mammalian features.  Therefore, birds and bats do not comprise a monophyletic clade. 

One of the key attributes of cladistic analysis is the fact that it can predict the presence of ancestral species even when we have no record of these species. For example, in the case of Archaeopteryx (and birds in general), almost all paleontologists would agree that these organisms are best classified as derived maniraptors.  The presence of many transitional features within Archaeopteryx (bony tail, claws, teeth, hip structure, neck shape, etc.) confirm this model, showing that Archaeopteryx, as a bird, had a demonstrably dinosaurian ancestry, specifically placing Archaeopteryx within a very specific branch of theropod dinosaurs, the maniraptors.  In instances where we cannot trace every transition in form from basal maniraptors into Archaeopteryx, scientists can infer the likely transitions that took place.  This is possible due to the fact that cladistic analysis focuses only on features unique to a single group within a clade. Thus, when antievolutionists claim that Archaeopteryx is nothing more than a “mosaic form” like the platypus, they are misrepresenting science.  Archaeopteryx’ features are transitional from a cladistic perspective, with features “in-between” that of basal theropods and modern birds, thus rendering Archaeopteryx a valid confirmation of evolutionary theory.  Archaeopteryx shares both basal and derived features with birds, thus passing the test of cladistic analysis.  The platypus, on the other hand, while having webbed feet and a bill, does not pass the key tests for “birdiness” (please note that this term is inherently unscientific, and is being used only for ease of explanation) such as presence of feathers, hollow bones, etc.  The basal features of the platypus place it on a basal tree of mammalia. 

Occasionally, Creationists will also use the claim that “since we can’t prove that a fossil reproduced, this means that it is not a valid transitional fossil”.  This is also a misrepresentation of how scientists think about ancestor-descendent relationships.  The search for transitions is not for transitional forms, but rather transitional features (as highlighted in Padian and Angielczyk, 197-231).  Thus, in the case of Archaeopteryx, to quote Padian and Angielczyk:

The point that we emphasize here is that the “bird” and “reptile” features of Archaeopteryx, or any such animal, can be explained in quite orderly fashion with  reference to their distribution on a cladogram… This distribution makes sense because it shows when each feature arose and was passed down, often in modified form, to the descendants of the first animals that had it.” (Padian and Angielczyk p. 209)

As demonstrated by the above quote, while Archaeopteryx has the characteristics to stand alone as a good piece of evidence for evolution, it is only in context where its significance truly makes sense.  If somebody asks for “just one transitional fossil”, as Creationists often do, they are misunderstanding how paleontology and taxonomy truly operate.  Through the use of cladistic analysis, scientists can pinpoint exact transitional features in context, rather than in a vacuum.  Nothing in evolution makes sense without context.  You cannot claim that a derived characteristic is transitional between two organisms if these organisms do not share the most basal characteristics on a cladogram.  Cladistic analysis always works from basal towards derived, so by the time one is ready to highlight “transitional features”, there is already a solid body of evidence to demonstrate a close relationship between the organisms in question.  It’s not just one isolated feature that’s important; it’s the sum of all parts.  Even while there are gaps in the fossil record, cladistic analysis allows to infer what is missing in these gaps, and even to predict what type of organism to expect in these gaps.  If you want to demonstrate to yourself that this process works, look up early amphibian evolution, remove any information on Tiktaalik rosea (to create a gap for yourself), and predict what type of transitional forms you would expect to appear in filling this gap.  Then compare your prediction with Tiktaalik’s description.  If you’ve developed a good prediction, it should line up pretty closely with the actual specimen.
 
Works Cited:
Holtz, T. and Brett-Surman, MK. The Taxonomy and Systematics of the Dinosaurs. In The Complete Dinosaur, ed. Farlow, JO and Brett-Surman, MK, Indiana University Press, Bloomington, 1997, p. 92-106.
Padian, K. and Angielczyk, KD.  “Transitional Forms” versus Transitional Features. In Scientists Confront Creationism: Intelligent Design and Beyond, ed. Petto, AJ and Godfrey, LR. WW Norton & Company, New York, 2007, p.197-231.