Sunday, October 31, 2010

A New Creationist Cosmology

In the latest issue of Acts & Facts, D. Russell Humphreys and Larry Vardiman have the first article in a series on Humphreys' latest revision of his "white hole" cosmology.   They claim that they have found a solution to relativistic equations that permit time to go on in one part of the universe while it stops entirely in a large region: this would permit stars and galaxies to form and age, and their light to reach Earth, while no time at all passed on Earth.  Thus the entire mutli-hecto-giga-galaxy of the "host of heavens" could arise in what would be, on Earth, a single day (indeed, a single instant of a single day).  The article itself provides only a simplified preliminary for a simplified explanation of the new solution, and no details of the solution itself.

Of course, if it did, I -- with my "B" average in high school physics -- would not be the optimal person to evaluate the authors' work.  But I find it somewhat odd that the authors published their paper in a creationist journal, and don't mention even trying to submit it to, say, Science or Nature.  If they're right, they've revolutionized our understanding of physics; one might suppose that mainstream cosmologists would be interested in their ideas even if they didn't like the young-earth implications that Humphreys and Vardiman draw from them.

There are a few details in their article that strike me as rather implausible.  They suggest, for example, that at the start of creation, the matter of the universe comprised a single sphere of "probably ordinary liquid H2O" a few light-years in diameter (this is inspired by Genesis 1's reference to "the deep" and the Spirit of God moving over the face of the waters).  I lack a PhD in physics, but I'm pretty sure that the laws of gravity don't permit a sphere several light years in diameter to be made of ordinary water; the water's own mass (and consequent gravity) would crush it into degenerate matter and then keep going.  God would need a miracle (on a scale that made, say, the feeding of the multitudes look like a card trick) just to keep "the deep" from turning into a black hole before He could turn it into those hundreds of billions of galaxies.

Note that this conjecture also takes the same approach to scripture -- that its true, inerrant meaning would have been opaque to the first 300+ generations of its readers, and even then be discernible only by advanced scholarship -- as James J.S. Johnson's article in the same issue of Acts & Facts.  Since the Bible speaks of a "firmament," and since Humphreys and Vardiman interpret this as referring not to the weather sky but to the entirety of the visible universe, they argue that this is teaching that the vacuum of space is really a plenum, a solid mass filling at least the entire Hubble volume, citing quantum physics and estimates of the vacuum energy to support their point.  References in Isaiah (and also in Revelation) to the sky being rolled up like a scroll are interpreted as references to a fourth spatial dimension large enough for the known three dimensional space to be rolled up in (as I understand it, this is a departure for standard "string theory" cosmologies, that invoke several additional spatial dimensions, but require them to all be very small in extent).

Well, I suppose that Humphreys and Vardiman can hardly be expected to take the literal meaning of the text: that the sky is a relatively flat surface that is very thin in the third dimension, like the tent over the "circle of the Earth" that Isaiah compares it to, and that "the heavens" is limited to this dome or canopy, and not a space extending many billions of light-years in all directions.

Both Humphreys and Vardiman have played a role in the ICR's RATE Project, attempting to show that radiometric dating is valueless.  Even were their arguments not flawed; invalidating radiometric dating would not really be "evidence that the Earth is young;" geological data known for the last couple of centuries, from angular unconformities in the strata to intersticed layers of saltwater and freshwater sediments to faunal succession in the fossil record would argue for an Earth very much older than the 6000 or so years that Humphreys and Vardiman argue for.  They've come up with a cosmological Rube Goldberg contraption and a very strained biblical exegesis to provide a cosmology that permits the Earth to be young when stars and galaxies are old, but the geology itself does not permit the Earth to be young.

Every Nation Under Heaven

This post deals with an article by one James J.S. Johnson in the latest edition of Acts & Facts, a publication of the Institute for Creation Research recommended to my attention by Dr. Alan ("barjona") Trimble.  The article has very little if any direct relevance to evolution (I hope to deal further with more evolution-relevant articles in the near future), but it offers an interesting look into the mindset of one particular creationist, and perhaps into the young-earth creationist mindset more generally.

The article deals with the interpretation of a sentence in Acts 2:5-11: "And there were dwelling in Jerusalem Jews, devout men, from every nation under heaven."  Taken literally, this is of course problematic, inasmuch as one would not expect there to be Jews from, e.g. the Andean Indian cultures present, or, most likely, from Han China or northern Europe.  Johnson considers the idea that the phrase is just hyperbole (the actual list of nations runs to fifteen, all in the middle east), a position advanced by some Christians Johnson commends for their high view of scripture, and one likely to be accepted by fair-minded skeptics.  But while he's not willing to rule out the idea that some passages in the Bible might be hyperbole, he doesn't like that idea for this passage.  Instead, he notes that it is important to seek out what the word translated "nation" (ethnos) in the biblical text itself, and then goes on to seek, in the Bible, a use of this word or its Hebrew equivalent goy that makes the statement literally true.  He doesn't appear to consider that there may be some tension between these two ideas.

Johnson finds a passage that will serve: the "Table of Nations" in Genesis 11 (he marvels "Isn’t it amazing how every major doctrine in the Bible, and every theological question, has a root in Genesis?" --  for my own part, I think I'd say that you can find the roots of every theological question there if you work hard enough to read them into the text of Genesis), which lists about seventy ethnic groups supposedly descended from the three sons of Noah.  Not all these groups can be definitely identified with any historically-known group (who are the "Sinites," for example?), but most can be, and all seem to have been living in the middle eastern region.  Johnson thus argues that Luke must mean that descendants of each of these seventy groups -- not, of course, the parts of these groups that had colonized Scandinavia or Australia or sub-Saharan Africa or the New World, but descendants of the original groups -- must have been present at Pentecost, and that Luke meant this.

That is neat, and slightly bizarre.  After all, on the face of things, Acts was written to "the most excellent Theophilus," apparently a Roman or Greek dignitary who desired to know more about the founding of Christianity.  One might suppose that Theophilus, or other early readers of Acts, may have been a bit shaky in their grasp of the Table of Nations (which Luke of course nowhere mentions explicitly), and not have been aware that Johnson's interpretation was even possible (after all, a lot of modern Christians with Genesis and Acts bound between the same leather covers apparently have missed it).  Johnson's interpretation, in other words, demands that the true meaning of a passage be one  that almost certainly was missed by the original intended audience.

Of course, a lot of creationist argumentation is like that.  From Ray Comfort -- and may other creationists -- arguing that Isaiah's reference to the "circle of the Earth" describes the Earth as a sphere (though we know that early Jews and Christians didn't read it that way, because they referred in some of their writings to a flat Earth ) to the insistence that the same passage's mention of "spreading out the heavens" refers to the expansion of the universe revealed through galactic redshifts (which interpretation would have been  unavailable to anyone prior to the 20th century), creationist surprisingly often insist that the plain meaning of the text must be something different from its plain meaning to centuries of earlier Christians and Jews.  Indeed, the whole idea that "created kinds" correspond to genera, families, or suborders rather than species is something that wasn't found in the text until the mid-20th century (though granted, if you go back before the 17th century, the idea of "immutable species" was impossible as the modern concept of "species" had not yet been invented).  One must wonder whether Johnson -- both a theologian and a lawyer -- could possibly reason his way to the conclusion that the real, true, hitherto undiscerned biblical meaning of the early chapters of Genesis referred to common descent with modification by natural selection.

AiG News to Note, October 30, 2010

Answers in Genesis refers to the discovery of  what appears to be a hundred-thousand-year-old Homo sapiens jawbone in China as "win[ning] two points for creationist views."  First, it contradicts evolutionary theories, and second, since the jaw's morphology seems intermediate between modern human and Neanderthal jaws (and thus implies interbreeding between H. sapiens and H. neanderthalensis), it contradicts the idea that there were multiple species  alive at various times in the  history of our species.  I should point out in passing that, by creationist logic, this is resting a rather large case on a rather fragmentary finding.  More relevantly, I don't see it as that big a problem even for mainstream reconstructions of human prehistory, much less for evolutionary theory in general.

Anatomically modern humans are known from fossils nearly twice as old as the new Chinese specimen.  It is certainly plausible that the migration out of Africa from which modern Eurasian, Australian, and American humans are descended was not the first attempt to leave the African continent by anatomically modern humans.  On the other hand, as the AiG article notes, paleoanthropologist John Hawks has noted that the jawbone is within the known range of variation of both modern humans and Neanderthals: while he himself suspects that its bearer had anatomically modern human ancestors, it might be just another "archaic H. sapiens" that has no effect on current theories of when and how humans spread out from Africa.  As the article also notes, there is no consensus on whether modern humans and Neanderthals were separate species or merely separate -- and sometimes interbreeding -- subspecies, implying that some evolutionists won't find their ideas challenged at all if this jawbone is indeed from a modern human-Neanderthal hybrid (there is in fact strong evidence that Neanderthals and anatomically modern humans interbred, but this may not have been more regular or common than, say, the interbreeding that sometimes goes on between brown bears and polar bears and may not imply that modern and Neanderthal humans were the same species).

Oddly, AiG nowhere takes issue with or even makes snarky comments about the dating of the fossil.  Given their persistent and adamant young-earth creationism, I wonder if they don't want to stress the point that "evolutionists" don't just make up the dates to fit their theories, but find the dates indicated by the evidence.

The AiG article next comments on  a story on how New Caledonian crows learn tool use from their parents.  After a brief diversion to another story about bees able to find the shortest path among a variety of flowers (the famously difficult "travelling salesman problem"), the article argues that this discovery contradicts evolutionary theory again, by showing that apes don't support evolution just because they're smart.  Well, of course, apes don't support evolution just because they're smart; they support evolution by numerous genetic and anatomical homologies with humans, and because humans are nested, anatomically and genetically, among other primates.  One would think that an organization that has figured out that evolution predicts an evolutionary tree of life rather than an evolutionary ladder, and is aware of the idea of convergent evolution, would realize that evolutionary theory is not overturned by the discovery that primates are not the only tool-users on the planet.

The "News to Note" article has a brief paragraph on a recent suggestion that a drastic rise in oxygen levels in the Earth's atmosphere a couple of million centuries before the onset of the Paleozoic (and the "Cambrian Explosion") was caused by algae blooms triggered by retreating and advancing glaciers of a worldwide ice age that reached, at the time, nearly to the equator (the "snowball Earth").  It notes, of course, that creationists only accept one ice age, right after Noah's flood about 4500 years ago, notes that the geological record isn't very complete, and segues into the question of how life could evolve to breathe oxygen in the first place.  It's not quite clear whether the writer grasps that the scientists who proposed the idea think that animals -- all of whom breathe oxygen -- already existed on Earth in very primitive forms such as sponges.  And it seems rather odd to argue that, given experiments in which bacteria evolve the ability to metabolize weird substances such as nylon, that mutations and natural selections are unlikely to be able to give an organism the ability to use oxygen.

The article goes on to consider a report of a headless dragonfly and part of a small lizard fossilized in million-century-old amber.   This of course confirms creationism because lizards that eat dragonflies exist today, and the amber is probably only thousands rather than tens of millions of years old.   "We would," the author explains, "certainly expect to find significant similarities of behaviors and ecosystems between the time periods."  Of course, we would, if we were AiG-style creationists, also expect house cats and lions to diverge from a single pair of ur-felids aboard Noah's Ark in under 5000 years, and perhaps even expect the entire Equidae, from Hyracotherium to modern donkeys and zebras, to similarly "microevolve" from a single pair of ur-equids in the same time.  It's not really clear, given that sort of warp-speed evolution, and the "world that perished" view of a radical discontinuity between the pre- and post-flood worlds, why creationism is more supported than evolutionary theory by the idea that lizards and dragonflies existed together in the days of the dinosaurs as they do today.

Finally, the article responds to a column on Physorg.com complaining that creationists attack Darwin personally rather than deal with evolutionary theory as it is.  The article points out, reasonably enough, that in fact many of its articles don't even mention Darwin.  The author omits, though, quite a few AiG articles that deal with the supposed evil effects of people accepting Darwin's ideas rather than with either the scientific merits of the theory or the modern theory as opposed to Darwin's own formulations.

Saturday, October 30, 2010

Answers in Genesis, not in Apes (Part 2)

The current issue of Acts & Facts (the journal of the Institute for Creation Research) has an article by Randy J. Guliuzza, MD, titled "Similar Features Demonstrate Common Design."  Although superficially similar in theme to the AiG article by the Viets, Guliuzza goes into considerably more depth in his argument.  He starts by noting that evolutionary theory deals in "function," not "purpose;" it explains a bird's wing or bat's wing in terms of mutations selected for their ability to aid in gliding or flying, not for a Creator's purpose in creating a flying animal.  This doesn't, really, offer much of an explanation of why, e.g. a bat's wing, a whale's flipper, and a human arm have such detailed correspondences in their skeletal structure, or why there are such differences in the way the tetrapod forelimb is modified into a wing in pterosaurs, birds, and bats.  Guliuzza mocks evolutionists for refusing to acknowledge "purpose," but he doesn't really offer any "purpose" for such a pattern of similarities and differences in living things.

Rather, he goes on to offer a series of not-terribly-coherent attacks on evolutionary theory and methodology.  He argues, e.g. that to properly understand homologous structures, we must:

  • Stop looking to the extrinsic environment coupled to natural selection to explain the origin and primary source of adaptive capability, and start looking to the built in diversifying reproductive power of organisms. Environments do not select organisms for habitation. Rather, organisms occupy environments when they generate traits that fit.
  • Drop the evolutionarily-tainted belief that answers to what causes adaptive change can be reduced to one or several components (e.g., DNA) of organisms—a fallacy basic to assertions of bit-by-bit origins from individual parts—and begin treating the entire organism as the minimum component necessary to reproduce, adapt, and fill environments.
  • Embrace the search for purpose as a guide for biological research to encourage the broadest array of questions and testing of all possible explanations.
Now, the first of these points seems weirdly wrong: organisms often occupy environments to which they are only indifferently fit.  The Italian wall lizards that evolved cecal valves in their guts on Pod Mrcaru didn't occupy the island because they were already ideally fitted to it: they did so because they could survive, and over time their descendants became better able to survive on a new diet in a new environment.   The same principle is seen in bacterial cultures that evolve traits ranging from antibiotic resistance to the ability to digest nylon.  The environment is not the "primary source of adaptive capability;" it is the source of selective pressures on the capacity of organisms to reproduce and mutate.

Obviously, entire organisms reproduce.  Indeed, quite a bit of evolutionary theory deals with the constraints on evolution imposed by the fact that isolated bits can't evolve by themselves: whether a given change is beneficial or not depends not only on that change, but on how it affects other parts of the organism, from the energy costs of building it to the effects on the development of other organs or structures (one species of blind cave fish, for example, seems to have its vestigial eyes selected for not directly, but as a side effect of selection for a larger jaw; as the jaw grows larger in embryonic development, it leads to shrinking of the eye -- which implies that the larger jaw wouldn't be beneficial if the fish needed to see, even if it made feeding easier).  But "begin treating the organism as a whole" doesn't give much guidance in explaining how adaption -- even the sorts and degrees of adaptions accepted by creationists -- occur.

And as noted, the "search for purpose" doesn't do much to account the question the article is supposed to be addressing: why, e.g. detailed similarities exist between structures that serve vastly different functions, whether the forelimbs of moles and bats, or the GULO gene in moles and the GULO pseudogene in old world anthropoids.   Guliuzza wants to argue that living "kinds" were created with the in-built ability to evolve so far and no further, but offers neither a real mechanism nor a basis for built-in limits that would prevent, e.g. humans and macaques from sharing a common ancestor.  Guliuzza argues that:
Any explanation must explain these observations: diversity within, and similar features between, kinds of organisms; and stasis, meaning a fossil and its living counterpart show remarkably little change.3 Biological life is fundamentally discontinuous, meaning organisms fit only one phylum, class, and order. Common descent explanations generally clash with these observations.
Note that "stasis," as commonly used by paleontologists, means that a fossil species does not show microevolutionary change across its geological duration.  It doesn't mean that sequences of species don't exist that demonstrate significant change over time (and Guliuzza has already conceded microevolutionary change, and probably accepts, as other ICR writers do, speciation within "kinds").  Note also that species fitting into only one phylum, class, order, etc. is in fact a prediction of branching descent with modification: nothing in creationism prevents, e.g. something like centaurs that nest in multiple different places in the nested hierarchy simultaneously: a "creation model" is compatible with, e.g. bats with feathers or birds with mammary glands in a way that evolution is not.

Guliuzza goes on to make a rather strange argument, possibly having changed trains of thought halfway to his demonstration.  He notes that gene regulatory networks that accomplish similar ends often use very different sequences of regulators, and hence are regarded as having evolved convergently.  He then goes on to mock the fact that although evolutionists explain homology (detailed similarity in structure beyond that needed to account for similarity of function) in terms of common ancestry, they do not explain analogy (lack of similarity beyond that needed to account for similarity in function) this way: an obvious contradiction, by his lights.

Frankly, his entire article, despite bursts of erudition, is a mess.



Answers in Genesis, not in Apes (Part 1)

Darius and Karin Viet, apparent newcomers to Answers in Genesis, have an article on that website titled "Why Did God Create Apes with Human Features?"  The article is in response to a question from an Australian reader: "If God knew that apes and the like would be used so passionately by evolutionists to support their theory, why did he create them?"   The authors give the answer that God did so to demonstrate His creative power, though this doesn't really address the question of why God didn't demonstrate his power by creating something that wouldn't fit so well a theory of common ancestry of humans and other species (well, in the end they do address that question: "because He wanted to;" creationism has often been cited as a science-stopper, but the Viets seem content to let it be a theology-stopper too.

The authors do hint at another possible divine motive: "belief in man as a highly-evolved ape may become a sign of judgment when man honors the creature rather than the Creator."  God created apes, in other words, so that if we were minded to reject or question His revelation in the Bible, we would have something to pin our evolutionary hopes on.  Or perhaps God made apes to teach us to trust his word rather than our own judgment on the evidence.  On the other hand, the authors don't seem to think (or at least, don't concede) that evolution has anything significant to do with evidence in the first place.
Third, God focused on the disease (sin) instead of the symptom (evolution). Since the all-knowing God knew evolution would deceive many people, why did He create creatures like apes, which evolutionists would use to support their dogma? If God had not created apes, however, evolutionists would just find another “common ancestor.” The problem is not the evidence, but sinful man’s faulty interpretation of the evidence made in a futile attempt to avoid recognizing the Creator, Law Giver, and Judge. Instead of not creating things Satan would warp for evil, God sent the remedy for the deadly disease of sin: the Lord Jesus Christ.
The authors may be new, but they seem very familiar with the Answers in Genesis mantra: evidence by itself proves nothing; it all depends on the "presuppositions" you bring to the evidence.   Now, this comports rather ill with the fact that many Christians, even evangelical Christians, nonetheless find the evidence compelling, even when their presuppositions include the idea that Jesus Christ is Lord.

The authors assert that "similarities between organisms" do not constitute evidence for evolution.  They speak of "the evolutionary idea of homology," although homologies were named by the anti-Darwinist comparative anatomist Richard Owen, and were recognized earlier: Pierre Belon du Mans identified homologies between a bird skeleton and a human skeleton in the 16th century, and such (still unnamed) homologies formed the basis by which Carolus Linnaeus, in the 18th century, classed whales with mammals rather than fish, and arranged thousands of species in the nested hierarchy that Darwin and later evolutionists were to use as the principal line of evidence for common ancestry.

"Homologies" are not just similarities: they are similarities that are not required for similarity in function.  The evidence for evolution is not just that apes and monkeys are, in their faces and hands and bodies, eerily reminiscent of human beings, but in that there's no obvious reason that they ought to be.  Why, e.g. should humans (most of us, anyway) have a plantaris tendon, corresponding to the tendon that in apes and monkeys clenches the feet into a fist, but which in humans does not even connect to the foot bones?  There's even less reason, other than common ancestry, why, e.g. humans should have more genetic similarities to chimpanzees  than gorillas do, or why humans and other old world anthropoids should share identically-disabled GULO pseudogenes.

Wednesday, October 27, 2010

Appearance of Age versus Appearance of History

Dr. Tommy Mitchell of Answers in Genesis has a new article on an argument creationists shouldn't use: the idea that "God created things to look old" or the "appearance of age" argument.  Instead, Mitchell counsels, creationists should say that things were created "mature" and ready to function.  Adam, for example, did not look, say, twenty years old; in those original days in the Garden of Eden, Adam would have no idea how long it took human beings to grow up or any idea that he looked any older than the few days he could remember (one might raise the objection that as Adam grew older and raised sons and daughters, it would have occurred to him that he didn't recall ever being a boy, nor had Eve ever been  a girl.  Mitchell seems here to be arguing that something has not been created with the "appearance of age" unless the observer at the time it is first observed has a sense of how long it should "normally" take to achieve that appearance or level of maturity.  He goes on, of course, to dispute mainstream scientific ideas about "fallible dating methods," although he does not go into details, and to suggest that we have no idea what a young universe or Earth should look like, and hence no reason to assert that this one looks old.

Now, why some creationists have argued for an "appearance of age," it should be noted that an "appearance of age" is really an "appearance of history."  Even a radiometrically dated rock is dated by inferring a history: many of the initial radioactive atoms have decayed, and we have measurements telling how long that would take.  An omnipotent Creator could, one would suppose, create rocks containing radioactive isotopes without creating large amounts of their decay products with them.  He could create trees without multiple rings showing of alternating breadth, hinting at nonexistent dry and wet years.  He could create Adam without, e.g. half-digested food already in his stomach, or healed fractures and scars from the childhood Adam never had.  And really, if you accept that Adam and Eden were literal and real, and that a global flood is not only possible but can alter dozens of radioactive decay rates in perfect synchrony, then perhaps God did do so.

But there are, in nature, many other indicators of history.  There are distant galaxies whose distorted shapes match computer models of what would happen if galaxies collided -- and galaxies, being the size they are and the speeds at which they move, take millions of years to collide.  Answers in Genesis has tried to get around this by suggesting that time might move faster the further away from Earth one is, so that distant galaxies might indeed be billions of years old while the Earth is only thousands (this is a rather unparsimonious suggestion, as well as unbacked by any evidence beyond the need to somehow reconcile a literal-inerrantist reading of Genesis with astronomy, but it does implicitly acknowledge that the universe appears to have a history because it does have one).

The implicit history in fossils and strata is dealt with, of course, by attributing most of them to Noah's Flood (and by dealing as little as possible with angular unconformities in the strata, and faunal segregation and succession in those same strata).  But there are yet other indicators of history.  Was Adam created with a functional GULO gene, that somehow became identically-disabled to match the GULO pseudogenes that either "micro-evolved" or were created in other old world primate species?  Was he created with 24 pairs of chromosomes, two of which fused to leave his descendants with 23 pairs?  How does Mitchell propose to explain the host of apparent relics of history in our genome, from disabled copies of the cytochrome-c gene (shared, again, with other primates at the same loci), pseudogenes homologous to genes used in other species for a sense of smell rather more discriminating than our own, etc.?  The pseudogenes by themselves imply either creation with an appearance of history (pseudogenes implying ancestors in which they were functional) or a truly astonishing amount of genetic history to pack into the few hundred generations that Answers in Genesis allows for our species, even without considering how much of that history is apparently shared with other species.

Tuesday, October 26, 2010

Does Intelligent Design Explain and Unify Scientific Data?

In the spirit of not trying to lure readers in by creating artificial suspense, the answer to the title question is "no."

In the spirit of getting something posted on the blog, though, I'm responding to the latest post by Casey Luskin on the Evolution News & Views blog.  Luskin is unhappy with with the suggestion that "intelligent design" is based on mystery -- unsolved questions in biology and other sciences, to be met with a "god  of the gaps" argument. Luskin argues that in fact, there is a positive argument to be made for ID.  ID proponents infer design, he claims, because they find in nature the same sort of features which result, in our day to day experience, only from design: things like:  "A vast amount of information encoded in a biochemical language; a computer-like system of commands and codes that processes the information in order to produce molecular machines and multi-machine systems."

But this is confusing drawing an analogy with actually finding the thing used as an analogy.  The genetic code can be compared to a a language; it is not actually a language, but a set of chemical reactions.  The genome and gene expression can be compared to a computer program, but a gene that regulates another gene isn't really a command line that calls up a subroutine.  And organic molecular systems can be analogized to machines, but calling them machines begs the question that Luskin purports to raise.

In many respects, biological design does not resemble human design; these respects (e.g. the consistent nested hierarchy of homologies, the use of dissimilar structures for similar functions (analogy) or similar structures for dissimilar functions (parahomology).  These dissimilarities have long been cited as phenomena that common descent can explain and that common design cannot (granted, as Luskin has previously noted, "ID ... does not intrinsically challenge common ancestry," but one wonders why, if a Designer is constantly intervening over the course of evolution, He refrains so consistently from copying design elements across lineages).  And then, of course, there are designs that work towards contrary ends: e.g. the keen eyes of predators and the camoflage of prey, or the infectious abilities of pathogens and the capabilities of hosts' immune systems.  These would imply, at least, either a multiplicity of designers or a Designer working for a multiplicity of clients.  To argue for design in the face of so many features that differ from the way known designers work requires that ID abjure and denounce any hypotheses about the motives, methods, and design philosophy of the Designer, which in turn means that they cannot find confirmations of such testable hypotheses about the designer, which means, in turn, that they are indeed reduced to "god of the gaps" arguments: "non-intelligent causes cannot, so far as we know, do this."

Luskin goes on to list various ways in which ID supposedly illuminates a broad range of scientific fields (basically, by encouraging us to marvel at the "design" in all of them).  But he also makes some specific arguments about the scientific testability of intelligent design arguments.
ID begins with the observation that intelligent agents produce complex and specified information (CSI). Design theorists hypothesize that if a natural object was designed, it will contain high levels of CSI. Scientists then perform experimental tests upon natural objects to determine if they contain complex and specified information. One form of CSI is irreducible complexity, which can be tested for by experimentally reverse-engineering biological structures through genetic knockout experiments to determine if they require all of their parts to function. When experimental work uncovers irreducible complexity in biology, researchers conclude that such structures were designed.
This is really awe-inspiringly confused.  "Complex and specified information" is not notably well-defined, which makes it difficult to say whether it has really been observed or not.  Dembski's most famous criterion for identifying it, the "explanatory filter," tries to find it by ruling out regularities of nature, then ruling out contingent combinations of regularities of nature and random chance, and identifying anything that can't be so explained as "CSI" and hence designed.  And this procedure would work very well, if we already knew every law of nature in the universe, and all the possible ways they could interact under all possible conditions.  But one would suppose that were we possessed of such near-omniscience, we wouldn't actually need the explanatory filter.

But assuming that it can be defined and is found to exist and is not defined simply as "complexity produced by intelligence and not by non-intelligent causes," then identifying it doesn't, in fact, rule out the possibility that non-intelligent causes could produce it.  Conversely, it is perfectly possible for a designer to seek simplicity, or complexity that serves no particular function except to look interesting.  So even a designed artifact will not necessarily contain "high levels of CSI" (note that it was William Dembski who first raised this point).

But in any case, "irreducible complexity" as Behe defined it, does not rule out explanations in terms of mutation and natural selection.  This was first shown, years before Behe was born, by the geneticist Hermann Muller, who used the term "interlocking complexity" for systems in which mutations had first built up and then eliminated redundancy.  Given that mutations can alter the functions of components of molecular systems (e.g. making them better at one function while robbing them of another) or delete them, it does not follow that a system that can be rendered nonfunctional by removing one component could not have been built up by mutations and natural selection.

In practice, testing of the ID hypothesis still comes down to arguments from personal incredulity and god of the gaps arguments.

Did Dinosaurs Eat Your Ancestors?

The "Cretaceous Terrestrial Revolution" (abbreviated "KTR") refers to the appearance of many modern groups of plants in the Cretaceous period.  Marsupials show up then, as do the first eutherian mammals (though there is no fossil evidence yet that true placental mammals existed during the Cretaceous -- though some estimates for the diversification of mammalian orders suggests that they must have existed at least as far back as ninety million years ago).  Flowering plants appeared and diversified rapidly.  Grass seems to have been present; at least, phytoliths (mineral inclusions in plants) similar to those in the grass family have shown up in coprolites (fossilized dung) from the late Cretaceous.  Birds of course were diversifying and taking on fairly modern appearances, as were many modern orders of insects such as wasps, ants, butterflies, etc.  But a study performed at the University of Bristol suggests that dinosaurs did not take part in this explosive diversification, and questions whether they exploited the new biological resources that were becoming available at this time (said resources including our tiny, shrew-like ancestors).

Their research involved trying to construct a cladogram of approximately 400 species of dinosaurs, as well as determining when the various species had branched off from earlier ancestors.  This was of course complicated by the notorious imperfection of the fossil record cited in previous posts: not only is fossilization rare, and not only are most fossils still undiscovered and undescribed, but some periods are better represented in accessible rock formations than others.  To compensate for this, researchers discarded data from the better-represented periods until they had samples from a similar volume of sediments for each era (they note that this method can be criticized, but it seemed more objective than inflating the number of species from poorly-sampled ages).  When this was done, dinosaur taxa seemed to radiate early on in their history and by the Cretaceous the production of new taxa had leveled off: the dinosaurs (birds presumably excepted) were no longer generating new species as fast as other groups like mammals, lizards, and insects.  The implication drawn was that they were holding their own but not innovating drastically.

Now, obviously, if those phytoliths mentioned above were really from grasses, and the coprolites containing them were in fact from dinosaurs (from their size and type, they were thought to be from titanosaur sauropods), then dinosaurs must have been at least occasionally exploiting some of the new resources.  And typically, carnivores are less choosy about their diet than herbivores; one must suspect that many of the maniraptoran theropods would not have turned down a chance to dine on early primates, if any were around in the late Cretaceous.    All we can be sure of was that if dinosaurs did eat any of our ancestors, it was after they had already reproduced, so thank a Troodon for its self-restraint.

Monday, October 25, 2010

Would Thomas Aquinas Have Been an Evolutionary Psychologist?

The question asked in the title was raised by a post by Jay W. Richards on the Evolution News & Views website.  His post was in response to Huffington Post article by Matt J. Rossano (head of the Psychology Department at Southeastern Louisiana University), who noted that many of Thomas' arguments anticipated "Darwinist" explanations for human behavior (e.g. the need among most humans for two parents to care for a child as a basis for marriage -- and even the analogy between the behavior of humans and birds in this matter).  The article also drew responses from one "vjtorley" and Joe Carter, the web editor for First Things.  You will perhaps not be astonished to learn that none of the above respondents found it likely that Aquinas would have endorsed evolutionary psychology, although Joe Carter grudgingly allows that Aquinas might have accepted common descent itself.

Now, the more I think about questions of this kind, the harder it is to figure out what the question actually means. If we ask, e.g. what Martin Luther King would have thought of the Tea Party movement if he were alive today, it's easy enough to imagine him still around at 81 years old and still holding much the views he held right before his death.  If we want to ask, though, what Martin Luther (the German religious reformer) would have thought about, say, gay rights (and the question has been asked, trust me), a problem arises.  Are we talking about Martin Luther somehow surviving and being a lucid and outspoken (and probably very fixed in his ways) 526-year-old?  Are we considering using a time machine to pluck him out of the sixteenth century, giving him a few months to acclimatize to the twenty-first, and then asking him (once he calmed down from the shock)?  Or are we asking what someone identical in traits and temperament to Martin Luther, but born, say, in 1960 in some heavily Roman Catholic region (i.e. not his native Eisleben, these days) of Germany?  I think those would be three very different questions and might have rather different answers.

By the same token, if we ask what a modern version of Thomas Aquinas would have thought, we need to ask "would he even be a theologian, or even a Christian, today?"  P.Z. Myers briefly argued this point in a post yesterday: in thirteenth century Italy, the brightest, most inquisitive people went into the church because it was pretty much the only intellectual game in town.  A Thomas of Aquino born seven centuries later might very well have become a scientist rather than a priest and monk, and might have been as casual about his theology as a lot of Italians are today.  Even had he gone into the church, his theology might well have been closer to Theodosius Dobzhansky's than, say, Christoph Shoenborn's.

If we're asking, rather, what would the original Thomas have thought about evolution, and evolutionary psychology, if he'd somehow been able to learn about them, that's hard to say.

It's easy for vjtorley to say, of course: as he sees it, four elements of Aquinas' theology militate against evolutionary psychology if not against common descent with modification altogether:

  1. Thomas was an essentialist (Darwinism is radically anti-essentialist)
  2. Thomas thought that God had made everything perfectly (no kludges or jerry-rigs).
  3. Thomas thought that God had personally made nothing useless or redundant (no vestiges).
  4. Thomas thought that God had made everything personally (no unguided causes).
In other words, if Thomas Aquinas had not changed any of his other views, he would not have abandoned creationism (given the number of assumptions about the nature, motives, and methods of the Designer in that list, though, could he have been an ID proponent?).   

Vjtorley goes on to argue that even a modern Thomist who accepted common ancestry could not reconcile that theological system with "Darwinism," though I'm not convinced by his arguments: the idea that, e.g. the world contains exactly the right amount of evil (necessitated by free will) would not depend on whether mindless evolutionary processes themselves could decide such things, but whether God in His wisdom could have decided that a "Darwinian" world would allow the optimal balance of freedom and necessity for all creation, including the non-human parts (as modern theologians such as John F. Haught have argued).

Thomas Aquinas also thought the sun orbited the Earth.  The question is, how many of these beliefs would  he have found reason to alter, as he learned of the advances of science over the succeeding seven centuries?   The "anti-essentialism" of evolutionary theory, after all, is not some random philosophical point; it is based on the actual observation of ubiquitous variation of living species in the field, on the observed mutability of domestic species, on the difficulty in many cases of deciding whether different populations (living or fossil) ought to be considered the same species or not.  Likewise, the idea that vestiges and kludges exist is based on comparative anatomy, not on a sense of what unguided natural evolution "ought" to do.  To argue that Thomas would not have abandoned it is to argue that Thomas would base his views on obstinacy rather than evidence and logic.  And as for the purely theological elements of his  thought, the very fact that the leading Catholic theologian dates from the 13th rather than, say, the 2nd, century, argues that theology can change and develop over time; its assumptions are themselves more mutable than the laws of the Medes and Persians were said to be.

It would be difficult to cast off the mental habits of his 13th century upbringing (not to mention abandoning positions he'd already staked out), but Rossano has a point: Thomas went somewhat beyond that upbringing already by incorporating so much of Aristotelian philosophy into his theology; it is reasonable to suppose that he would try to do likewise with later philosophy and science.  Evolution, and evolutionary psychology, would have been harder to accommodate than, say, heliocentrism or atomic physics, but not necessarily impossible.

Although vjtorley would, I think, want to think of it otherwise, he's basically arguing that Thomas Aquinas, even given access to modern scientific data and arguments, would reject evolutionary theory in favor of religious dogma as vjtorley has done.  Perhaps he would have (which does more to undercut the value of Thomas' opinions than it does to undercut evolutionary theory); this question, as I imply above, is interesting in part because there's no discernible way to definitively answer it.

Carter argues specifically against Thomas' ability to accept something as "dumb" as evolutionary psychology.  Now, here it's important to note that there is a difference between accepting that our minds have been shaped by evolution and accepting the views specifically labelled "evolutionary psychology," including: 
  1. All our mental traits are adaptions (there are no mental "spandrels")
  2. The mind comprises multiple specialized modules (no general intelligence).
  3. Human mental evolution stopped on the African savanna 100,000 years ago.
And even accepting evolutionary psychology would not mean accepting every "just-so" story about various human behaviors.  One might well suppose that the Angelic Doctor would not subscribe to vulgarized and dogmatic forms of evo-psych (those which Carter regards as the entire field) and still suspect that he'd find much of interest and even value in it.  But then, perhaps a modern-day (or modernly-educated) Thomas Aquinas would be among the harshest and most trenchant critics of evolutionary psychology.  The point remains: what Thomas thought would not settle the question of whether evolutionary theory, or particular applications of it to human psychology, were true.  I'm not sure that it would even settle the question of whether it was compatible with some form of Christian theology (which has, after all, evolved in its own way quite a bit over nineteen centuries).

In the end, the argument has been interesting, but isn't really to the point -- at least not if Intelligent Design is really about the science and not about religious dogma.

Saturday, October 23, 2010

The Obligatory Happy Birthday Earth Post

Today is, according to the chronology worked out by Bishop James Ussher (1581-1656), and not adjusted for the shift from Julian to Gregorian calendars, the sixth thousand thirteenth anniversary of Earth's creation.  Strictly speaking, according to Genesis, at the end of the day the Earth was still a chaotic, muddled, lifeless mess because all God had got around to doing was creating light, but frankly, haven't we all had days when it just seemed that we'd worked hard all day and got very little done (but at least we could see what we'd done)?

Tomorrow will mark the 6013th birthday of the creation of the sky, a fine accomplishment for all of you who enjoy breathing.  Monday, of course, will mark the birthday of the creation of dry land, Tuesday, of grass, trees, moss, algae, herbs, and presumably fungi of all types (for those of you who enjoy breathing oxygen, specifically).  On Wednesday, please remember to commemorate the creation of approximately 100 billion galaxies and all their myriads of myriads of stars, along with innumerable planets and moons (possibly but not necessarily including Gliese 581g).

Thursday will be the 6013th anniversary of the creation of fish, whales, sea urchins, marine molluscs, marine arthropods, marine everything else, birds, bats, and pterosaurs.  Presumably manatees and feathered dinosaurs rounded out the day.  And Friday, of course, is according to Ussher the 6013th anniversary of our own beloved species, along with Tyrannosaurus rex, Smilodon fatalis, and Dimetrodon macrospondylus.  According to Answers in Genesis (which is not celebrating this day, for some reason), all of these were vegetarians; I don't think the good bishop insisted on that.

Darwinian Assumptions and Extraterrestrial Life

Casey Luskin has a brief article on the ever-popular Evolution News & Views site.  It concerns a Fox News story about a possible (though thus far unconfirmed) somewhat Earthlike planet orbiting Gliese 581.  Steven Vogt, one of the astronomers who thinks they've discovered a planet there, said originally that he had "almost no doubt" that there was life there (and, rather confusingly, that he thought the chances of life on it were 100 percent; possibly that was rounded up to the nearest ten percent).

Anyway, Luskin promptly demonstrates a few things.  First, he does not quite grasp the meaning of "almost," declaring that Vogt had "no doubt" that there was life on Gliese 581g.  Granted, Vogt contributed to Luskin's confusion by giving the chances of life at 100%; still, the distinction between "no doubt" and "almost no doubt" approximates the distinction between almost falling off a cliff and actually falling off it.  

Second, he does not quite grasp Vogt's argument.  It is not, as Luskin puts it, "Dr. Vogt has "no doubt" that life evolves and exists elsewhere because he knows that it evolves and exists elsewhere."  Rather, Vogt assumes that because life is common and adapted to some rather extreme environments on this planet, it would arise on and thrive on any planet which had similar environments to those that harbored life on Earth (and while Gliese 581g is thought to be "Earthlike" in only a limited sense: three times Earth's and keeping one face to its sun at all times, it might indeed have niches not much more hostile than some that bear life on Earth) (assuming, again, that it meets one particular criterion that Earth does, actually existing).   Vogt doesn't actually explain why he thinks life is likely to arise on a suitable planet in the first place; I would guess that he reasons (as others have) that since life arose so early on Earth, abiogenesis is not, in fact, .very improbable (or else perhaps he thinks life arose in space and spread throughout the galaxy from wherever it started).

Third, Luskin seems to have some slight problem differentiating between the position of one "Darwinist" and another.  Accepting evolution doesn't involve accepting any particular idea about the probability of abiogenesis (except perhaps that it has to be at least as high as "once per universe," or at least, that however unlikely it happened at least once).  "Darwinism" does not depend on any particular idea of how or where life originally arose (strictly speaking, it does not depend even on the assumption that abiogenesis was a natural phenomenon).  As P.Z. Myers noted on his blog Pharyngula, we don't have any idea what value to assign to the chances of life arising on another planet -- and one might suppose that Luskin has both heard of Myers and regards him as a user of "Darwinian logic."   Vogt's reasoning is his own; it is not "Darwinian" to a greater extent than Myers'.

Of course, Luskin's incomprehension may well be tactical.  He wants to demonstrate that "Darwinists" make hasty, unexamined assumptions (about common ancestry, about the efficacy of nonmagical causes, about the likelihood of life in space), and picks an extreme example (which he then rather misrepresents) to make his case.

There is another point, though.  Luskin goes on to state that the theory of intelligent design (that would be "somewhere, sometime, somehow, Somebody did something, and furthermore, evolutionists are wrong about something or other") is compatible with life on other worlds.  He just wants to make sure that the problem is approached scientifically (which I would suppose means  that if we find extraterrestrial life, we declare that this is evidence for design, and if we don't, we declare that that is evidence for design).

I'm not sure whether he's hedging his bets against the chances that scientists actually will find extraterrestrial life, or whether he thinks that such a thing is to be expected.  After all, if you think that the universe was designed for a purpose, and that life was designed for a purpose, one might suppose that the Designer wanted to make a universe that had life in more than one out-of-the-way planet (and of course "life" is not the same as "intelligent life," and does not raise the same theological conundrums such as "why are extraterrestrials being punished for Adam's sin?").

Thursday, October 21, 2010

Good News and/or Bad News

Gerardo Aldana, an associate professor of Chicana and Chicano Studies at U.C. Santa Barbara, has argued that the now-traditional correlation between Mayan calendar dates and Gregorian calendar dates may be mistaken.  Granted, they may not be mistaken, but there is a margin of error measured in decades.  Aldana is the author of one chapter in the new book Calendars and Years II: Astronomy and Time in the Ancient and Medieval World.  According to reports on the web, Aldana has shown that work by Floyd Lounsbury in the 1970s that supposedly confirmed earlier correlations of the two calendars did not in fact prove that a unique correlation between the two calendars.

This is of course important because it raises the possibility that the world will not, in fact, end in 2012, as many popular books on the "2012 phenomenon" have suggested, but perhaps many years later -- or, conversely, that the world in fact ended decades ago, and we just failed to notice.  This news will perhaps come as a relief to Harold Camping, who predicted that the world would end in 1994 (Gregorian calendar), though he has since moved on to a new date, so perhaps it will not comfort him.

That the end of a period of the Mayan calendar does not, in fact, signify the end of the world is of course another possibility, arguably the only one actually backed by logic and evidence, but it's not nearly as interesting.

Wednesday, October 20, 2010

"Junk DNA" and Science Stoppers

The Discovery Institute's Evolution News & Views has an article by one "Jonathan M." entitled, as approximately one Discovery Institute article per month is required to be, "Yet More 'Junk DNA' Not-so-Junk After All."   It concerns a paper in the journal Cell discussing how long non-coding DNA strands near genes could affect gene expression, and goes on to note that while creationism and ID are often condemned as "science stoppers," it is ID that leads us to suppose that non-coding DNA probably serves some sort of function and encourages scientists to look for it.

It is nowhere suggested, to be sure, that the authors of the paper are ID supporters or were motivated in their research by a suspicion that the genome is "rationally designed."  But what struck me was that one of the first intimations that non-coding DNA played an important role in the functioning of the genome was Barbara McClintock's (ultimately Nobel-Prize winning) attempts to make some sense of the vagaries of corn genetics.  She was not moved to find a function for transposable, non-coding elements after their existence was shown; she was moved to posit them and perform painstaking experiments to show they existed because she needed something like them to explain why corn didn't follow straightforward Mendellian rules.

Granted that McClintock had difficulty convincing fellow botanists of her theories, it remains the case that the discovery of noncoding DNA was more or less simultaneous with the demonstration that some of it did something.  And then, of course, there was Ernst Mayr's initial suspicion of the whole idea that there were significant amounts of nonfunctional DNA in the genome: if it had survived natural selection, he first assumed, it must do something.  "Pan-adaptionism" is at least as compelling an argument for the functionality of "junk" DNA as design (a Designer, after all, might indulge in nonfunctional decorations of the genome according to His own ineffable aesthetics), although as Richard Dawkins has pointed out, we always need to consider that some parts of the genome might be adapted to help those parts survive, not to help us survive, and as Stephen Gould was fond of insisting, we cannot assume that everything about living organisms actually is an adaption.

Some "junk" DNA is plainly vestigial (and note, of course, that "vestigial" is defined as exhibiting reduced function, not nonexistent function): the famous GULO pseudogene in old-world anthropoids, or the numerous disabled genes for smell in human beings.  The notion that such genes are "junk" was based not on the assumption that they must have no function, but on the observation that they clearly didn't have the functions one would normally expect of DNA.  That "junk" could turn out, on occasion, to serve functions for the organism is no more astonishing or contrary to "Darwinism" than is the idea that random mutations in general could, on rare occasions, be beneficial or bestow novel traits.

That some "junk" is in fact pretty nonessential, though, was demonstrated by another scientific paper, Nóbrega, et al.'s "Megabase deletions of gene deserts result in viable mice" (Nature 431, October 2004), which showed that a million or more bases could be removed from some segments of a mouse's genome without affecting development in any noticeable way (note that some attempts did result in nonviable mice, which shows that the deleted segments contained important segments, not that the entire segments were functional; if you can find a million bases in a row that serve no vital function, there are probably a lot more shorter segments interspersed among functional segments that really are nonfunctional as well as noncoding).

As noted above, given that we are entitled, per ID principles, to no assumptions about the aesthetic or design principles of the Designer, it does not follow that function-free "gene deserts" contradict the design hypothesis (indeed, it's famously difficult to think of any possible observation that contradicts the design hypothesis).  But one wonders if a commitment to the idea that the genome was rationally designed rather than opportunistically evolved would lead to this particular "fruitful research."

Monday, October 18, 2010

God and Evolution Revisited

Jay W. Richards, Program Director for the Discovery Institute Center for Science and Culture, has the introduction to his new book, God and Evolution, available on line.  Additionally, on the DI's Evolution News and Views site, he has a post linking to an article by Msgr. Charles Pope on whether you can be a Catholic and uncritically accept "Darwinism" (note that Pope's comments are specifically Catholic only in that they don't insist that scripture has to be perspicuous -- interpreted "literally" -- to be inerrant; they are otherwise broadly applicable to Christian and conservative Jews).  Both writers seem content to accept the Big Bang, an old Earth, perhaps even common ancestry -- though both note that there are creationists who object strongly to some or all of these, they do not see these, by themselves, as insuperable obstacles to incorporating evolution and theism.

Rather, all three articles have a problem with the idea that evolutionary theory excludes God as a cause of biological phenomena.   Both authors seem to assume that "God didn't do it" is a key ingredient of evolutionary theory.  And both note, correctly, that quite a few biologists have explained evolutionary theory by contrasting it specifically with teleological processes.  Neither notes that this might be because, in the first place, there is a great deal of creationist opposition to common descent and adaption by natural selection, or, in the second place, that many people (both creationists and laymen who "believe in evolution") still have a vaguely Lamarkian, "evolutionary ladder" view of evolution in which humans are indeed the goal and inevitable result of evolution.  That is, evolutionary theory is not so much being defined as non-teleological or godless as being contrasted with distorted views of how it works -- or why it could not work.

That being said, evolutionary theory indeed doesn't invoke or incorporate a Creator at any stage in the theory.  Neither, to be sure, do atomic theory, or orbital dynamics, or meteorology.  Richards at one point notes that Newton was not trying to exclude God from the study of planetary orbits, but does not note that Newton's attempt to find a niche for Him to work in -- adjusting planetary orbits in small ways that his equations didn't quite predict -- was discredited by more careful calculations involving the gravitational pull of planets on each other.  By the time Pierre Simon Laplace got through with Newtonian dynamics, they no longer had any explicit role for God.   But then, Laplacian physics undercut only the "Prime mover" argument for God, which is always getting mixed up with the "First Cause" argument anyway and probably never had much traction as a defense of theism in its own right.  Evolutionary theory undercut the much more distinct and impressive argument from design (it also contradicts a perspicuous reading of Genesis, which probably aggravates the problem even if one doesn't explicitly accept six-day young-earth creationism).

This may explain why there are quite a number of areas where Richards, in his Introduction, seems quite content not to have any explicit acknowledgment of God.  He argues that the Big Bang, including stellar nucleosynthesis and even, presumably, the naturalistic origin of stars and planets, is quite compatible with theism and a belief in divine design.  The Bible may say that God created the Earth to be inhabited, but Richards apparently feels that this is compatible with God setting up the laws of physics so that at least one inhabitable planet would be formed eventually (though I'm not sure that this is compatible with EN&V's glee over the possible nonexistence of one such planet).   Richards isn't (nor is Pope) asking for a God Who hand-crafts the orbits and chemical makeup of individual planets.

Richards also notes that evolutionary theory has been applied, loosely and figuratively, in Niall Ferguson's The Ascent of Money, to the survival or failure of financial institutions.   He seems to have no problem with the idea that historical processes, in general, play out due to natural processes and human decisions (or to the idea that "due to human decisions" and "in accordance with human wishes" are not at all the same thing: history isn't necessarily what anyone actually wanted).  Nor does Pope insist that the Christian must incorporate God's providence into history as much as into the origin of species.  Yet the Bible is as clear and insistent on the idea that God is in charge of history -- that, e.g. He used the Babylonians to punish the Judeans for their sins against Him -- as it is that God is Creator of living kinds.  One might suppose that ID proponents would be as worried about the extreme (one might say vanishing) subtlety with which God seems to direct history (what exactly is God supposed to have done to make the Babylonians invade Judah on schedule? what was He doing during so much of church history?) as they are about finding gaps in the history of life that divine providence can fit into.  Of course, Richards probably assumes that all his readers will accept that God has acted, miraculously and spectacularly, on occasion in history; the problem is trying to make sure that God doesn't seem as if He's just sitting idly on the bench throughout all of prehistory.

For both Pope and Richards, it is not cosmology, or the age of the Earth, or even common descent, that is the sticking point; it is the idea that all this happened without some sort of plan, something that led up to humans.  Neither is quite clear what sort of role for God they want.  Pope insists that God must sustain and somehow direct evolution, though he offers no suggestions for what God might be doing.  Richards casts subtle aspersions on the ability of natural selection of random mutations to craft the avian lung or the human conscience, but he doesn't seem to want to rest his case purely on the insufficiency of known natural causes (possibly, at some point, it's been pointed out to him that from Darwin on down, "Darwinists" have noted that natural selection of random variation is surely not the sole cause of evolutionary change; other natural causes are possible and incorporated as evidence supports them -- and other natural causes might be involved even if we haven't guessed at them yet).   They seem to want something more than a mere verbal acknowledgment that, okay, a Christian can believe that God created and sustains evolutionary processes, and made them so that they would produce creatures who can believe in and love Him.  But it's not clear how much more they want.  Pope simply advises caution; Richards may hope that one of the contributors to his volume can add more.

The underlying problem, of course, is that science deals with what can be understood and supported by evidence.  ID proponents have noted in the past that "naturalistic" science has historically had no problem with intelligent designers, as in archaeology or forensic science.  The problem is, those designers need to operate according to discoverable regularities of their own nature.  And the larger problem, of course, is that there needs to be some evidence for them besides the felt need to reconcile science with religious dogma, and beyond the (admittedly multiply-confirmed) prediction that "somewhere, somehow, there's something that evolutionary theory can't explain yet."

Sunday, October 17, 2010

Vestigial Organs Revisited

Answers in Genesis has an article, "Vestigial Organs: A Vanishing Argument," that is noteworthy if only because it's the first creationist article I can recall that notices that "vestigial" refers to reduced function of an organ or structure rather than strictly nonexistent function.  To be sure, having made this concession, the author comes close to taking it right back: he states that we would have to demonstrate that a structure has "minimal or no use in its present form."  But then he gets back on track and makes the main argument of the article: to establish that an organ is "vestigial," we have to engage in circular reasoning, and assume what we're trying to prove: that the organ has an evolutionary history and precursors that did more in ancestors than they do in living descendants.

Both arguments miss the point.  One of the classic arguments for common descent with modification is "parahomology," or, as Darwin called it, similar structures serving dissimilar functions.  The flipper of a whale, the wing of a bat, and the arm and hand of a human being show striking similarities in skeletal architecture, considering the very different uses to which  these different forelimbs are put.  Bring in the foreleg of a dog or cat, and the question arises: why should modifications of the same basic plan be put to such diverse uses -- especially when we have (e.g. in the inverted retina of the vertebrate eye and the "right-side round" retina of the cephalopod  eye instances of dissimilar structures serving very similar functions)?  Evolutionary theory answers this: parahomologous structures are opportunistic modifications of a structure inherited from a common ancestor.

"Vestigiality" is a subcategory of parahomology: it refers to cases where the most conspicuous function of a structure in most species that have it is lacked by some species.  Now, "vestige," itself, does indeed reflect the conclusion that these structures are explained by evolution, but the basic observation does not assume common ancestry.  You don't have to assume that a dodo shares ancestors with flying pigeons to wonder why it had wings at all, since it didn't fly.  You don't have to start with the assumption of common hominoid ancestry to note the human plantaris tendon, and realize that in humans, unlike other hominoids, it doesn't enable us to clench our feet into fists (it doesn't even reach the foot bones).  You don't need to assume that vampire bats had ancestors who ate solid food to note that some species have small, rounded cheek teeth where other bats have molars suitable for grinding food, and wonder what vampire bats need these structures for.  Darwin called such structures "rudimentary" rather than "vestigial," and merely noted that they could most readily be explained as vestiges that had lost some of but rarely all of their functions.  They can be defined and recognized without any reference to evolution or common ancestry (and then used as evidence of that common ancestry).

Indeed, the philosopher John Wilkins once pointed out, on the Talk.Origins newsgroup, that one could recognize vestigial structures in cases where evolution wasn't even a possible explanation for them.  Consider the very reduced (in anatomical structure and function) limbs on many children of mothers who took thalidomide during pregnancy.  These are clearly reduced in function compared to their obvious homologs in related individuals, yet they clearly have nothing to do with evolution (thalidomide is a teratogen, not a mutagen, and these children can have children of their own with normal limbs; the effects of the drug are not inheritable).  But of course the point is that one can recognize vestigial organs in many cases where known mechanisms -- reproduction, inheritance, mutations that reduce function, genetic drift and natural selection -- can explain them, and do so better than any other explanation that has been offered: why else should such structures fall into nested hierarchies where other branches are occupied by species whose homologous organs have the additional, obvious function?

Of course, the author exhibits a small problem with understanding the classic mechanisms of evolutionary change.  He asks:
What is the mechanism that leads to loss of function? For example, consider the appendix, which was classified as a useless evolutionary leftover (although its function has been demonstrated in recent years). Evolutionists have postulated that in the past, man had a larger cecum, but as man progressed from a higher-fiber diet to a lower-fiber diet, the larger cecum became less necessary. Thus the appendix is said to have resulted from a loss of cecal size. What is not explained is just how a change in diet would change the DNA—adding, subtracting, or modifying information—in order to bring about this structural change in man.
A change in diet is not thought to have changed DNA.  Random copying errors that went on all the time produced changes in the size and shape of the cecum.  As the diet changed, though, changes that would once have been detrimental (because they left the mutant less able to digest food, hence less nourished and weaker) became neutral, perhaps even beneficial (since resources weren't being expended to build a large organ that wasn't necessary).  A change in diet changed which variations were "fittest" and most likely to survive; it didn't create the variations directly.

God and Evidence

Over the past week, Jerry Coyne and P.Z. Myers  have been engaged in an argument by blog over whether it is even logically possible for there to be evidence for God (both agree that there isn't actual evidence; the disagreement is over whether anything could be evidence if it existed).   Myers has staked out some positions that seem dubious (for example, that the concept of God is too ill-defined for us to say what could constitute evidence for it: as Coyne points out, "evidence for God" normally means "evidence for an all-powerful, all-knowing supreme Being, and if there were evidence for such a Being,, it presumably would rule out some concepts of God and be compatible with others), and some that invite deeper consideration.

Myers raises what looks, at first glance, like a logical error: he argues that if evidence for God could appear, wouldn't this mean that all current religions that get along without such compelling empirical evidence must be false?   But while absence of evidence is not automatically evidence of absence (it depends on how likely an entity or phenomenon is to leave empirically detectable traces), obviously, a God Who intended to make His existence obvious is capable of producing evidence, over and over again, that no one could miss.  That we don't see (to cite some examples given by Coyne) routine miraculous healings in response to prayer (to one particular conception of God, and not to other gods or to other conceptions of God), or water being turned into wine by prophets empowered by this God, argues that if there is a God, He doesn't wish to make His existence blatantly obvious.  Therefore, a blatant miracle (say, a 900 foot tall apparition of Jesus visible to multitudes of independent witnesses -- which, pace Myers, doesn't seem by itself more out of character for some biblical depictions of God than a pillar of fire or a burning bush), or the sudden commencement of a consistent pattern of less blatant miracles, would be too obvious, too out of the character God has evinced over the last fourteen to twenty-four centuries (depending on which Abrahamic religion one is asking).  This would at least argue that the traditional monotheistic religions had been advancing mistaken ideas about God.  We'd have evidence of something, but it might not be God as any traditional religion conceived Him.

But perhaps this is, like Doug Adams' "Babel fish" argument for the non-existence of God, taking a philosophical point a bit too far.  Of course, both Myers and Coyne note that evidence for God might be interpreted in various ways.  Myers, for example, suggests that if he witnessed an unmistakable miracle, he'd be more likely to conclude that he was hallucinating than that he was reliably witnessing a miracle.  One might get around this by asking what would happen if Myers' observation was supported by other witnesses as well.  When Coyne originally raised this argument, several commentators to his post noted, much more explicitly than he had, that it would be very difficult to distinguish between an actual miracle and the use of unknown technology to simulate a miracle.  This is indeed my own response to the problem of evidence for God: as finite beings, any phenomenon that we can perceive and wrap our minds around will be, itself, a finite phenomenon.  The most parsimonious explanation for anything -- from accurate, detailed prophecy of the future to healing amputated limbs -- is unlikely to be an infinitely-powerful, all-knowing Being.  Laws of nature we don't understand are more parsimonious than an Author of natural law able to amend them or make exceptions to them at will.

And here I seem to find myself siding with Myers against Coyne.  Coyne posits a documented series of nature miracles performed by someone who looks like and claims to be Jesus, and asks:
Now you can say that this is just a big magic stunt, but there’s a lot of documentation—all those healed amputees, for instance.  Even using Hume’s criterion, isn’t it more parsimonious to say that there’s a God (and a Christian one, given the presence of Jesus!) rather than to assert that it was all an elaborate, hard-to-fathom magic trick or the concatenation of many enigmatic natural forces?
It seems to me that the question is, is it more parsimonious to infer a finite but powerful being (possibly using unknown technology) who quite possibly has in the past established himself as the Christian God, or to infer an actual, omnipotent, omniscient, omnibenevolent Being when all you've seen is demonstrations of finite albeit great power?  Of course, awed by the impact of the events, and influenced by childhood upbringing, one might not be inclined to be rigorously parsimonious.  But I think the underlying principle remains.  Establishing the existence of God through the preponderance of evidence is not, I think, logically possible.

Saturday, October 16, 2010

Answers in Genesis Explains It All

The hot news on the creationist/ID front (featured on both Evolution News and Views and the AiG website) is that the most Earthlike exoplanet ever discovered may not exist.  Now, obviously, if "Earthlike" can be defined precisely enough, there must be a "most Earthlike exoplanet," but a team of astronomers trying to confirm the existence of a three-times-Earth mass planet in the habitable zone of Gliese 581g has been unable to do so.   From this embarrassment it follows, logically, that "evolutionists" are prone to premature announcements based on dubious and indirect observations that are quickly discredited.  What remains fascinating is the apparent determination of creationists and ID proponents that the Creator/Designer should not have put evidence of His handiwork on any planets but this one.  For open creationists, this makes sense (for some values of "sense"): if the entirety of creation has been cursed for Adam's sin, then it would be unfair (more so, apparently, than merely cursing all Adam's descendants and all life on Earth) to punish extraterrestrials for a sin committed on Earth.  But ID proponents aren't supposed to be creationists or committed to religious doctrines like the Fall and Original Sin.

Answers in Genesis goes on, in this weeks News to Note, to announce that creationists may be receiving help from dead fish, perhaps as science advisors.   Studies of rotting fish have shown that even where soft parts are preserved, some soft parts -- including parts that especially distinguish more advanced species from more primitive members of their clades -- are especially unlikely to be preserved.  From this, AiG confidently infers:
 More importantly, the research suggests that—at least in some biological taxa—there may be a systematic bias making fossils appear more “primitive” than they actually were; and by decreasing the frequency of supposedly primitive fossils, evolutionists have even less of an example of progressive evolution over time.
Apparently, Microraptor and Caudipteryx, if we only had complete specimens, would turn out to be modern bluebirds, and the braincases of the Dmanisi H. erectus specimens probably shrank after death.

Citing research at Emory University, Answers in Genesis marvels at how monarch butterflies lay their eggs preferentially on more toxic species of milkweed when the butterflies are infested with the parasite Ophryocystis elektroscirrha, apparently as a form of chemical warfare against the parasites.  AiG finds it especially intriguing that the mother butterfly does not benefit from this; only the offspring do (with the implicit question of how natural selection could favor behavior that improved only one's chances of leaving behind more copies of one's genes).  The article goes on to remark on God's benevolence and forethought in providing the monarch butterfly with a way to cope with the parasites He cursed it with in the Fall.

And AiG refers to the recent discovery of the prosauropod Sarahsaurus aurifontanalis in Arizona.  Given that this dinosaur doesn't seem to be specialized for a purely vegetarian existence, but may have been an omnivorous scavenger; it has caused some paleontologists to speculate that sauropodomorphs didn't spread through North America because they were better than local herbivores; rather, they spread out and specialized after a niche for large-bodied hervibores was opened by the extinction of earlier dinosaurs.  AiG is surprisingly objective in its recounting, not even mocking the idea that there might have been meat-eaters before the flood (though in the past they've been more open to scavenging than predation in pre-Flood animals); it just notes that this goes to show how much we still have to learn about dinosaurs (that one thing we've learned is that they were around a long time before 4000 BC is, of course, just reliance on human reason rather than on revealed truth).

For their last item, AiG's weekly News to Note, they take on Jerry Coyne's recent article stating that "Science and Religion Aren't Friends."  If you're familiar with Ray Comfort, you're familiar with the litany of criticisms: without God, Coyne has no basis for moral judgments, Coyne can't prove that there is no God (and the burden of proof is apparently on him to do so),  that there's no basis for assuming reason works except a creationist basis (which goes on to argue that since creationism provides the only basis for assuming reason works, we should abandon reason and trust in AiG's interpretation of God's word).

And speaking of abandoning reason, AiG deals with Coyne's claim that a billion-year-old ape fossil would justify abandoning evolutionary theory, by turning around and asking whether, e.g. a living "ape man" would have the same effect.  Given that AiG already includes, on its "list of arguments creationists should not use" page, the "if we evolved from monkeys, why are there still monkeys" argument, I can only assume that while the authors understand that ancestors can continue to exist after descendants arise, they haven't quite figured out that this isn't reciprocal: descendants can't live before their ancestors do.