Archive for July 2009

Hugh Falconer

July 28, 2009

According to Stephen Jay Gould (2002 p. 745), Hugh Falconer might be remembered as one of the greatest Victorian paleontologists if he had not died before publishing major works.  However, unfortunately for Falconer’s legacy, this was not the case.  Falconer died at the age of 57 in January 1865, during the last year of the violent and bloody US Civil War (for general biographical sketch, click here).  Gould obviously held Falconer in high regards, even though most people today have never heard his name.  Let’s take a look at why.

Falconer performed his most recognized work in India, a place he was transported to by the British East India Company in 1830 (see biographical sketch).  He is remembered, if at all, for his work on the mammalian fauna of the Siwalik (also spelled Sivalik in some texts) Hills (see for example Mayor 2001 p. 133, Chakrabarti  2004 p. 72, Gould 2002 p. 745). Through his work on the Siwalik Hills fauna and his later 1863 monograph on fossil elephants, Falconer observed and noted the prevalence of “stasis” in the fossil record.  By the publication of the 1863 monograph, Falconer had accepted the general premises of Darwin’s model (although he was critical of it previously…more on this later). If the term stasis brings to mind Eldredge and Gould’s theory of punctuated equilibria, it should.  Eldredge and Gould’s work on punctuated equilibria was essentially a re-discovery of what Falconer had already observed; Falconer noted long-term stability of species, with an occasional sudden appearance of new species.  Thus, Falconer noted a key observation of punctuated equilibrium, namely that:

“a local pattern of abrupt repalcement does not signify macromutational transformation in situ, but an origin of the later species from an ancestral population living elsewhere, followed by migration into the local region.” (Gould 2002 748)

More specifically, Falconer was referring to European fossil elephants, and placed their likely ancestral stock in India.  Falconer started out critical of Darwin, so much that when Darwin sent Falconer a copy of The Origin of Species, Darwin noted in a letter that included with the book that:

“Lord, how you will long to crucify me alive! I fear it will produce no other effect on you; but if it should stagger you in ever so slight a degree, in this case, I am fully convinced that you will become, year after year, less fixed in your belief in the immutability of species.  With this audacious and presumptuous conviction, I remain, my dear Falconer, Yours most truly, Charles Darwin” (quoted in Gould 2002 p. 746)

This passage illustrates a few realities.  First, Darwin valued Falconer’s judgement (in fact, Falconer was one of the first scientists who Darwin described his theory to; see Gould 2002 p. 746).  It also implies that Darwin and Falconer were on somewhat friendly terms.  Desmond and Moore’s (Desmond and Moore 1991) biography of Darwin hints at this friendship as well, as do letters between Falconer and Darwin, for example Falconer offering specimens to Darwin, etc.  Something deeper is also at work here.  In Falconer, we see an early critic of Darwin who has been convinced of the strength and viability of Darwin’s model.  While Falconer still viewed evolution differently than Darwin to a degree, Falconer had warmed to the strength of Natural Selection.

Falconer is less remembered for his views on Archaeopteryx.  In 1863, Falconer wrote to Darwin, stating:

You were never more missed—at any rate by me—for there has been this grand Darwinian case of the Archaeopteryx for you and me to have a long jaw about…You are not to put your faith in the slip-shod and hasty account of it given to the Royal Society.  It is a much more astounding creature—than has entered into the conception of the describer” (Falconer, 1863 in Correspondences vol. 11 p.5)

Thus, Falconer was aware of the relevance of the find to Darwin’s work.  The above quote hints that Falconer may have viewed Archaeopteryx as some sort of “missing link”, perhaps between reptiles and birds.  This passage also hints at a friendly relationship between Falconer and Darwin (for more on Darwin and Archaeopteryx, see my post on the topic here).  The passage also hints at some brewing troubles between Owen and Falconer; Falconer viewed Owen’s description of Archaeopteryx as “not…well done” (Footnote 10, here)

One other facet of Falconer’s career that is often overlooked is his rough relationship with some other Victorian scientists, most notably Richard Owen.  As Darwin wrote in his 1887 Autobiography (quoted here):

“Poor dear Falconer….had a very bad opinion of him, being convinced that he was not only ambitious, very envious and arrogant, but untruthful and dishonest.  His power of hatred was certainly unsurpassed.  When in former days I used to defend Owen, Falconer often said, “You will find him out some day, and so it has proved.”

Falconer had fought with Owen over some fossil specimens, as evidenced in this letter from Charles Darwin to James Dwight Dana. The footnotes to this letter are instructive in this case, with one stating that:

CD probably refers to Owen’s palaeontological work on the fossil elephant Elephas columbi, and the fossil rhinoceros Rhinoceros leptorhinus. With respect to E. columbi, Owen had overlooked Falconer’s description of the fossil elephant and had renamed it E. texianus. Falconer interpreted this move as an attempt by Owen to usurp his priority in the description of the fossil, by substituting another, and in his view inferior, name (see letter to J. D. Hooker, 3 January [1863], n. 1). Falconer’s critique of Owen’s E. texianus was published in Falconer 1863a, pp. 45–9 (see also letter to Hugh Falconer, 5 [and 6] January [1863], and letter from Hugh Falconer, 8 January [1863]). Falconer may also have told CD of his doubts regarding Owen’s identification of Clacton, Tuscan, and Rhenish specimens of fossil rhinoceros as R. leptorhinus (see Owen 1846b and Falconer 1868, 2: 317–20). “ (again, letter and notes available here)

Falconer challenged other scientists as well.  For example, he debated with Huxley over methods of paleontology (see letter between Darwin and Hooker, here).  Falconer also butted heads with Charles Lyell (see a second Darwin and Hooker letter, here).  Falconer was clearly a man who was not afraid to ruffle some feathers.

However, in a society rich with scientific visionaries, it is all too often the case that some individuals get overlooked.  Hugh Falconer is one of these individuals.  Mention the words “Victorian” and “scientist” in a sentence, and most people will think of Darwin, Owen, Huxley, Lyell, Wallace, or some other well-known scientist.  Falconer operated in the same scientific arenas as these men, and often butted heads with some of them.  He was a relatively close friend of Darwin (see Desmond and Moore 1991 p. 528 on Darwin’s reaction to Falconer’s death for example).  He anticipated a modern development in evolutionary theory.  Yet hardly anyone knows his name. 

 

 

Works Cited:

Chakrabarti, P. Western Science in Modern India, Permanent Black, 2004

Desmond, A. and Moore, J.  Darwin: The Life of a Tormented Evolutionist.  WW Norton & Company, New York, 1991.

Falconer, H. letter of Jan. 3, 1863 to Charles Darwin.  In The Correspondence of Charles Darwin Vol. 11, edited by F. Furkhardt, DM Porter, SA Dean, JR Tophan, and S. Wilmot.  Cambridge University Press, Cambridge, 1999

Gould, SJ.  The Structure of Evolutionary Theory.  Belknap Harvard, Cambridge, 2002

Mayor, A. The First Fossil Hunters: Paleontology in Greek and Roman Times. Princeton University Press, Princeton,2001

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.

Christian and non-Christian creationist movements

July 6, 2009

When the term “creationist” is mentioned, most people take the term to be analogous with the term “Christian Creationist”.  However, there are many different religiously-driven creationist movements, all attacking evolutionary theory and other scientific ideas, and all working under different religious frameworks.  Therefore, while the Christian Creationist is perhaps the most familiar figure to most readers, many people from non-Christian belief systems can also be considered “creationists”, albeit with differing beliefs.

Some of these non-Christian creationist groups (as well as many Christian ones) operate outside of the United States.  For example, there are Hindu creationists operating in Asia, and Islamic creationists operating in Turkey.  Like Christian creationists, these groups attack not only the science of evolution, but also the perceived threat that evolutionary theory creates towards moral values. For more on these groups, see Numbers 418-427.  creationist movements are truly a global phenomenon.

However, for the purpose of this discussion, let’s focus on an often overlooked creationist movement operating within the borders of the United States.  The most visible antievolution movements within the United States include the fundamentalist Christian Young Earth Creationist movement and the less overtly religious Intelligent Design movement.  However, these movements (as well as Islamic, Hindu, and Jewish movements) are not the only such movements operating within America.  We’re going to look at something more local. 

Therefore, let’s turn our attention towards Native American creationist movements.  Like other religiously driven antievolution movements, Native American creationists seek to challenge science when it challenges their own religious belief systems.  However, unlike the Creation Science movement (an expression of Christian Young Earth Creationism), which has failed legal attempts to challenge evolution (in this case, in the classroom), Native American creationists have a possible legal structure to successfully challenge scientists.

This legal structure is known as the Native American Graves Repatriation Act (NAGPRA), passed in 1990, which allows tribes to claim ancestral remains (as well as artifacts) held by museums and agencies that receive federal funding (Mayor 302).  NAGPRA is intended to protect Native American interests, especially in cases where museums have historically collected large amounts of Native American artifacts and remains, often without tribal permission.  While NAGPRA does not currently cover fossils (305) unless these fossils are a piece of an obvious artifact such as a medicine bundle (the status of fossils is defined under the Archaeological Resources Protection Act (ARPA), passed in 1979, see Mayor 305), some people, such as Allison Dussias, feel that fossil remains should be protected as cultural items, due to the role that fossils play in some Native American myths (Mayor 305).  Therefore, the status of fossils, while currently legally defined by ARPA, could hypothetically be altered at some level in the future.

In some cases, considerable controversies can develop around ancient human remains found within the United States.  For a quick case study, take Kennewick Man.  This skeleton, found in the bank of the Columbia River, was a relatively significant find at about 9200 years old.   Under NAGPRA, a group of tribes filed for custody of the skeleton for burial, while the scientists who discovered the skeleton sought to study the remains. Eventually, a federal judge ruled that the skeleton was too old to establish a “cultural affiliation”, thus nullifying the tribal claim to this skeleton (Mayor 395).

This incident is instructive because it highlights Native American thoughts towards science in general.  The Umatilla, one of the five tribes who sought custody of Kennewick Man’s remains, offer an especially good look at these issues.  Kennewick Man was initially believed to be most closely related to Europeans; later studies suggest a closer affiliation to the Ainu of Hokkaido (the northern island of Japan) (Schnee 1999).  Both of these interpretations of Kennewick Man can be interpreted to contradict the creation story of the Umatilla, who believe that their ancestors have always lived in the Americas . Some Umatilla members view any study that contradicts Umatilla beliefs as inherently disrespectful (Egan 1996), bringing to mind Christian Creationist beliefs about evolution. 

When cases such as this are considered, it is easy to see how NAGPRA can be used as a legal tool to protect Native American belief systems; remains that seem to contradict a tribe’s creation story could be sought under NAGPRA for reburial.  Given the language of NAGPRA, it is plausible that some such challenges could be won by Native American peoples.  Therefore, unlike Christian Creationists, whose legal strategy has been overtly defeated at the Supreme Court level, it is possible for Native Americans to win some legal battles over remains which seem to contradict their own creation stories (the case of Kennewick Man was initially a victory for the coalition of tribes involved until a federal judge overturned the ruling for the reasoning stated above; Mayor 395).  If the legal structure shifts to incorporate fossil remains, a shift which would prove difficult (and I would guess unlikely), then the results could be drastic.  However, NAGPRA is not meant to challenge archaeology and anthropology, but rather to protect Native American interests. In the vast majority of cases, NAGPRA is utilized as it was meant to be.

Therefore, an assumption that all “creationists” are Christian Creationists is drastically flawed.  There are many different Native American groups, all with their own belief systems.  There are large-scale movements by Muslim and Hindu creationists as well (as alluded to early on).  There are plenty of antievolution movements that one could focus on.  Therefore, whenever someone implies that there are only two sides in a discussion over evolution (evolutionists and Christian Creationists), their position is irreparably weak.  When I use the phrase “the Creation-evolution struggle” in posts, I’m referring specifically to Christian creationist movements, not because they are the only antievolutionist movements, but because in those cases I am referring explicitly to these movements.  Given the comparably mainstream coverage of Christian creationist movements, they tend to be the most well-known.  However, they are not the only such movements in existence.
 
Works Cited:
Egan, T. Tribes Stop Study of Bones that Challenge History. National Report, The New York Times, September 30, 1996.
Mayor, A. Fossil Legends of the First Americans. Princeton University Press, Princeton, 2005.
Numbers, RL.  The Creationists: From Scientific Creationism to Intelligent Design. Harvard University Press, Cambridge, 2006.
Schnee, K. Make No Bones About It. The Tech. Online Edition, Vol. 119, Issue 52, October 22, 1999.

aliens

July 6, 2009

Now, for a different angle, let’s take a look at aliens.  Don’t worry; I’m not advocating the myth that little green men from Mars are coming to Earth to eat our brains and rape our women.  Rather, I’m going to explore the modern structure of beliefs about extraterrestrial life.  Here, we’ll take a look at pseudoscientific claims about aliens visiting Earth in UFOs, the underlying assumptions of the SETI program and programs like it, and probe the possibility of some form of extraterrestrial life actually existing.

Perhaps the image most people have in mind when the term “alien” is mentioned is the classical Roswell-type alien.  You know the image.  A balloon-shaped head with huge eyes and a tiny mouth.  This head is attached by a short inconspicuous neck to a body with two legs, two arms, shoulders, a torso, and four to five fingers on each hand.  These things are bipedal, moving in human fashion.  If one were to probe the evolutionary history of these supposedly real aliens using only what we have available for evidence (that being alleged eyewitness accounts), these aliens would likely be classified within a quintessentially terrestrial system.  The reason is simple. The description given for these aliens suggests that the aliens are, in fact, derived tetrapods.  You’re familiar with these creatures.  Beginning with the evolution of early amphibians during the Devonian period, the tetrapod lineage has proven to be immensely successful.  Tetrapods include birds, amphibians, reptiles, horses, dogs, pandas, and humans. It’s safe to assume that most people would accept that these organisms are “earthlings”, native to our own planet.

Yet people who claim that aliens have visited Earth and even abducted humans often overlook this fact.  To assume that these humanoid aliens evolved on another planet far from Earth is to assume that an entire planetary history, almost exactly similar to that of Earth’s, has played out.  One must assume that the same selection pressures were present in both locations, thus fueling the development of a backbone or similar structure (these aliens appear to be vertebrates), a terrestrial lifestyle, exactly four limbs (rather than five, or eight, or two, for example), a head with two eyes, two nostrils, and one mouth, a bipedal stance, and also human-like intelligence with an emphasis on engineering, math, and science.  While convergence is a common trend within evolution (we see it in bats, birds, and pterosaurs, for example), convergence to this extent is pretty difficult to swallow.  To have the development of an almost exact replica of a human evolve thousands of light years away, while possible, is not exactly probable. And while some people claim that these aliens are visiting Earth, we should ask “why Earth?”, and also “why no physical evidence?”  If these aliens are visiting Earth, we should have some definitive physical evidence, not just some eyewitness accounts.   If, as some would claim, these aliens were instrumental in building the pyramids or the Nazca lines, then why don’t we have any physical evidence of their presence?

If you’re familiar with the work of Carl Sagan, you’re probably thinking “well yes, the aliens supposedly visiting Earth probably don’t exist, but the Drake equation suggests…”.  If you’re totally lost right now, things will make more sense if I briefly explain the Drake equation.  The Drake equation, a relatively speculative enterprise (mainly with regards to results, as they are extremely subjective) first explored by Francis Drake of Cornell University, seeks a number (N, which roughly illustrates the likelihood of extraterrestrial entities from within the Milky Way contacting Earth) by multiplying:
 
the number of stars in the Milky Way Galaxy by the fraction of stars that have planetary systems;
the number of planets in a given system that are ecologically suitable for life;
 the fraction of otherwise suitable planets on which life actually arises;
 the fraction of inhabited planets on which an intelligent form of life evolves;
 the fraction of planets inhabited by intelligent beings on which a communicative technical civilization develops;
and the fraction of a planetary lifetime graced by a technical civilization
” (Sagan 248)

As you can see, this is an extremely speculative venture.  First, we don’t have a solid number of planetary systems within the Milky Way Galaxy, or a good number of planets with life.  Thus, the outcome of this equation will vary by user.  While some people would rank the probability of the evolution of “intelligence” (by human standards; here meaning something along the lines of proficiency in math, science, engineering, etc.) on other planets as probable, this represents a specific progressive reading of evolution.  This interpretation of the way evolutionary theory works implies that natural selection naturally favors “intelligence” over other factors. However, this interpretation is flawed.  While “intelligence” certainly offers a selective advantage in some circumstances, a lack of “intelligence” does not always spell extinction.  Hadrosaurs prospered during the Cretaceous Period without being overly bright (judging from their brain cases at least).  The case for “intelligence” as the key beneficial trait for dominance is thus flawed.  “Intelligence” does provide a selective advantage in many cases.  However, other traits can also drive evolution. In terrestrial evolution, “intelligence” to the point of intellectual pursuit has only evolved once (out of 4.6 billion years of Earth history).  If you read evolution as inherently progressive, then it is natural that the human brain is a late appearance on Earth.  You also probably read the hundreds of millions of years before the arrival of humans (at least subconsciously) as leading towards the evolution of “intelligence”.

However, from a paleontological perspective, looking at Earth’s history, one sees a series of accidents punctuating evolution.  Early chordates survive the early Cambrian even as many other genera go extinct.  Early plants find a selective edge on land, leading animals to follow.  Mammal-like reptiles rise to prominence in the Permian, only to be all but extinguished by an extinction event at the end of the period (after which the dinosaurs take over for a huge chunk of time).  At the K-T boundary, the dinosaurs get wiped out, largely as a result of non-biological processes (likely a meteorite impact).  Earth’s biological history is filled with accidents, non-biological events that have had a biological impact nonetheless.  Chance occurrences can play a key role in extinctions, which can pave the way for an inconspicuous group to conquer the planet (I mean, seriously, who would have thought that a few tiny shrews would eventually produce one of the most dominant species that the Earth has ever seen?!).  It is likely that these chance occurrences are key on any planet.  Mars, Mercury, and the Moon have all been repeatedly pelted by meteorites, for example.  Mars has had some highly active volcanoes as well.  Geologic and cosmic events can have as much an effect on evolution as biologic ones. 

With this in mind, it becomes extremely difficult to argue that evolution is “progressive.”  There are illusions of progress, to be sure.  We have more “advanced” organisms appearing after less “advanced” ones.  However, these trends are necessary; one would not expect a dog to appear before mammals evolved, after all!  However, it is wrong to assume that natural selection is goal-driven (I am assuming that natural selection works on other planets because it is the only viable explanation we have for the diversity of life on Earth.  However, the concept should work on other planets as well, as long as there is some sort of competition among individuals).  Natural selection merely weeds out poorly-adapted individuals.  If a mutation were to occur that led to the birth of a litter of bright pink leopards, one would not expect them to survive for long, depending, as the species does, on camouflage for hunting.  Natural selection predicts that these individuals will likely be weeded out.  However, natural selection does not strive for the development of intelligence 4 billion years down the road, any more than I strive to ensure that my great-great-great-great-great-great-great grandchildren have food on their table by going to work today. 

Therefore, it is bad practice to merely assume that intelligent life exists elsewhere in the universe.  The universe is extremely large.  We don’t know everything about it.  Intelligent life may exist elsewhere.  However, from what we know about Earth’s history and evolution in general, it is likely improbable.  While it is likely that “simple” lifeforms (think bacteria) exist elsewhere, judging from the abundance of amino acids and other materials present in the parts of the universe our species has explored, this does not mean that these lifeforms are striving to become “intelligent” in the future.  They are merely attempting to survive.  “Intelligence” may have evolved elsewhere in the universe, but it is not because of some goal-driven process of evolution.  Unless selection pressures strongly favoring “intelligence” over other factors are present, it is very possible that “intelligence” has not or will not evolve elsewhere in the universe. 

Works Cited:
Sagan, C.  Cosmos. Random House, New York, 1980