Monday, November 15, 2010

Casey Luskin Takes on Homology

This is an excessively recursive post: my review of Casey Luskin's review (on the Evolution News & Views website) of Henry Gee's, Rory Howlett's and Philip Campbell's review (in Nature) of a scientific paper by Toshiyuki Matsuoka et al.  This is not "blogging on peer-reviewed research;" this is blogging on tendentious carping about a popularization of peer-reviewed research.

The paper describes Matsuoka's research into which parts of the skeleton originate from the neural crest cells formed in the outermost of the three layers (the ectoderm) of the developing embryo, and which parts originate from the mesoderm, the middle layer.  This, in turn, the Nature editors state, gives us insights into the evolution of the various parts of the skeletons of modern vertebrates.

Luskin makes two points.  The first is that Matsuoka's research doesn't depend on the assumption of common descent, and could be done simply on the basis of comparative anatomy.  I'm pretty sure this is true.  The second, which takes up most of his article, is that Matsuoka's research throws a monkey wrench into the whole idea that homology is a result of common ancestry (actually, it's not quite clear whether Luskin means to attack the whole idea of homology -- which was identified by creationist biologists before evolution was invoked to explain it -- or just "Darwinian" explanations of it).

Luskin notes that Matsuoka notes a bizarre feature of embryonic development across species: the development of muscles from particular groups of cells is far more consistent ("more conserved") than are the actual bony sites to which  they attach.  Matsuoka, rather than reject the idea that the detailed similarity in form, location, and embryology of the neck muscles are homologous, proposes a startling idea:
The rather counterintuitive "scaffold model" perceives muscle connectivities as the basic units (because they precisely correspond to cell populations) but considers the bones that everyone can see as mere epiphenomena and subjects of change.
Luskin mocks this as a "bizarre" conclusion, forced by Matsuoka's slavish adherence to the dogma of common ancestry.   But it's not entirely clear what is so "bizarre" about it.  Vertebrates, after all, don't literally inherit their bones, or muscles, or nerves, or other body parts; they inherit genes, which interact with cellular mechanisms to grow all these parts.  Genes are not literally blueprints; there is no gene for a scalpula located right next to the genes for the clavicle or cervical vertebrae.    Matsuoka is suggesting that rather than trigger bone development directly, genes trigger muscle development in such a way as to promote bone development, with some interspecific variation in exactly how they accomplish this.  Interestingly, David Klinghoffer has a post on EN&V today that makes just this point: the genome isn't literally a "code" or blueprint (how exactly this makes the case for intelligent design is not quite clear).  Luskin can't quite get his head around the point that just because bones are more likely to be preserved than muscles or genes, they don't have to be directly inherited rather than effects of things that are directly inherited (of course, as Upton Sinclair noted of some other people, his salary depends on not understanding certain things).

Luskin goes on to note some further oddities of the homologies in vertebrate skeletons, such as the apparent loss, on multiple occasions, of the cleithrum, the major shoulder bone of primitive tetrapods, in different tetrapod groups (frogs still retain it, though salamanders don't, and many ancient amniotes did, though no modern amniotes do):
You've got to love the last sentence, which is worth repeating: "We speculate that a common, as yet unknown, genomic cis-regulatory architecture governing neck ossifications in tetrapod ancestors might have predisposed different descending tetrapod lineages to similar parallel trends." This is almost starting to sound like teleological evolution--but of course that's not allowed in Darwinian thinking, so it's just by the luck of the draw that all of these taxa independently arrived at the same bone structure. 
Now, Stephen J. Gould used to argue against the instinctive resort to "adaptionist" explanations; not every feature of biology or evolution, he argued, was an adaption.  One alternative that he mentioned more than once was developmental constraints: species descended from a common ancestor inherited developmental pathways that made some possible evolutionary changes difficult or impossible, while making others very easy and likely to arise as a side effect of other changes, whether they were directly beneficial or not.   This is not "teleological" thinking, as though evolution meant to lose this bone in advanced tetrapods; this is a suggestion, very common in evolutionary thinking for a century or more, that some changes are easier and more likely than others, and thus are likely to occur independently in multiple lineages.

Luskin includes in the article a quote from the creationist textbook Explore Evolution:
In sharks, for example, the gut develops from cells in the roof of the embryonic cavity. In lampreys, the gut develops from cells on the floor of the cavity. And in frogs, the gut develops from cells from both the roof and the floor of the embryonic cavity. This discovery -- that homologous structures can be produced by different developmental pathways -- contradicts what we would expect to find if all vertebrates share a common ancestor. (Explore Evolution, p. 44)
The book is right: we would, as a first rough estimate, expect that homologous structures develop through homologous pathways.  On deeper reflection, though, it's not quite clear whether we ought to invariably expect that.  On the one hand, if genes and tissues can evolve, presumably developmental pathways can evolve also, and still remain homologous.  In principle, one might find that novel genes had taken over some part of a developmental pathway from the ancestral form, though given that the same genes are found in all cells of the embryo, this is hardly necessary; the phenomena cited by Explore Evolution could result  from changes in where various gene cascades were triggered, without much change at all in the genes that actually build the gut.

There's a point that keeps going through my mind as I read Luskin's articles on the Nature series on "Evolutionary Gems," and that is, how does this support design?  If he's denying that homologies exist, he's basically telling us to believe him and not our own (and several centuries' worth of comparative anatomists') lying eyes; if he's arguing that homologies represent "common design," then how is this helped by arguing that in fact the designs are not common at all?  The variations in detail of how vertebrate bodies are built with conservation of basic elements (across disparate body shapes and lifestyles) fits at least as well with our expectations of evolution as with intelligent design.  But then, we're not really entitled to have expectations of intelligent design; it's sole testable hypothesis is that somewhere, somehow, evolutionists have got some stuff wrong.  Unfortunately, that testable hypothesis doesn't really differentiate intelligent design from evolutionary theory, whose proponents have generally followed Charles Darwin in realizing that they don't understand everything.

Friday, November 12, 2010

Evolution News & Views on the Human Genome Project

The Discovery Institute's Evolution News & Views blog has posted an article (seriously, the author is given as "Evolution News & Views," so it's the intelligently designed product of another intelligently designed product, designed, in the opinion of its own designers, by intelligently designed products, so we're dealing with massively recurrent design here) on "The human genome project ten years later."  Research on the human genome has, as the blog sees it, has undermined "Darwinism" in a couple of different ways.

First, it notes, research has found that much so-called "junk DNA" is actually functional.  This is presumably relevant because, to ID proponents (or at least to their blogs), "junk" DNA is relevant as evidence for common ancestry and natural selection only because it's supposed to be useless.  But of course "junk" DNA, like other vestigial structures, is evidence because it is homologous to structures with entirely different functions from whatever function it might have.  It is an example of "parahomology," adaption of one structure to serve an entirely different use.  In principle, a pseudogene or endogenous retrovirus is evidence of the same kind as the homologies among a whale's flipper, a bat's wing, and a human arm and hand: even when they are all fully functional, their detailed similarities aren't required by their divergent functions, and are far easier to explain in terms of descent with modification from a common ancestor than in terms of separate origins (whether "common design" or some sort of separate evolution to fit their different niches).  Vestigial organs have from Darwin on been defined as lacking the most obvious or important function of their homologs, not as lacking all function, and there's no obvious reason this shouldn't apply to vestigial genetic elements.

On the other hand, large swaths of the genome in fact not only haven't been discovered to serve any function, but there is some evidence that they really don't have any function to discover; at least, they can be removed without any discernible effect.

Anyway, the blog's second, and main, argument, is that evolution (and the blog seems to mean common descent, not just naturalistic mechanisms to produce this effect, since it speaks of the inference of "evolutionary relatedness") is undermined because "scientists are coming to a sobering conclusion that perhaps their models and assumptions on the nature of disease may be mistaken."  Rather than most non-infectious diseases being, like sickle-cell anemia or cystic fibrosis, the results of single mutations to single genes, most, like breast cancer, are the result of subtle and hard-to-trace interactions among dozens or hundreds of genes. Given that the genome isn't literally a "blueprint," with one set of nucleotides corresponding to one particular trait, but that polygeny (multiple genes influencing a single trait) and pleiotropy (multiple traits affected by a single gene) have been necessary terms in genetics for decades, arguably this was more of a disappointment than an actual surprise to anyone: it makes finding cures for things more difficult but is pretty consistent with what has been known about genes since before the Human Genome Project was started.

The blog's opinion on this research concludes:
 Given the presupposition that a complex organism is engineered, then the parts themselves must be taken within the context of the whole. ... A reductionist, neo-Darwinian view of the human genome does not seem to have explanatory power regarding disease. This is a clear case where some scientists' dedication to the presupposition that similar DNA sequences means whole organism similarity, the same presupposition that many have used to argue for evolutionary relatedness among species and against man being anything more than another animal, has, 138 million dollars later, lead to more dead ends than cures.
 I find myself bemused.  From intelligently designed kitchenware that differs from other pots and pans because of single, "reductionist" features such as stickproof coating, to cars and computers chock-full of features and components that can be discussed and evaluated in isolation, "reductionism" seems an ubiquitous feature of human design.  It "does not seem" to me that one can simultaneously claim, as various human writers on Evolution News & Views have done, that "design" in nature is recognized by analogy to human design, and that "design" in nature can be recognized because it resists analysis in terms of modules, reductionism, and other methods used by human designers.

There is also an element of desperation in seizing on the discovery that trying to examine things as a collection of disparate components that produce no more than the sum of their parts doesn't always work.  I suspect, again, that actual scientists figured this out a long, long time ago ("make everything as simple as possible, but not simpler," as Einstein uncontroversially noted), but one has to look for simple patterns before one can make out the complicated ones.

And one must really wonder if the blog, or its human designers, assume that other animals really can be explained more reductively and simply than Homo sapiens.

Thursday, November 11, 2010

Mutation Rates and the Age of the Human Race

Brian Thomas, a science writer for the ICR, has an article up titled "New Genome Projects Data Indicate a Young Human Race."  He refers to three recent studies (done for the "1000 Genomes Project") summarized in the journal Science which determined that each human born carries an average of sixty mutations, down from an earlier estimate of one hundred.  Thomas raises two separate questions regarding this finding.  On the one hand, does the new lower rate provide for enough changes to derive humans and other primates from a common ancestor over the last few dozen million years?  On the other, will not the accumulation of harmful mutations over time wipe out the human species, and does this not imply a maximum possible age for the human race?

Thomas used a program called Mendel's Accountant to model a human population over time, assuming sixty mutations per individual.  He notes the result:
Assuming a population size of 2,000 individuals, assuming that each mother has six children, and using the rate of 60 mutations per generation in the algorithms, the simulation shows the extinction of the human race after only 350 generations. This also assumes that natural selection would have been effective at removing the least fit from the population every generation.
This account does not mention the percentage of mutations which are beneficial, harmful, or neutral or near-neutral, which the program allows one to select, and whose values, one assumes, would have major import on the outcome of the experiment.  I also cannot help but note that Thomas, as a writer for the ICR, is supposed to assume that human populations started out much smaller than 2000 individuals, and have apparently ended up much larger.  But that aside, Thomas notes that evolutionists assume that the human species is far, far more than 350 generations old (it is unlikely that H. sapiens is less than 10,000 generations old, and of course we have pre-sapiens ancestors going back long, long before that), whereas creationists assume that the human species is only about 300 generations old (having gone through a really intense bottleneck around 4500 years ago, when our effective population was reduced to Ham, Shem, Japheth, and their three unnamed wives; I wonder if Thomas tried to model that particular feature).

Here is one thing that struck me: the human genome is about the same size as most other mammalian genomes, and there's no obvious reason to suppose that our mutation rate differs much.  If we can't survive for a thousand generations, much less ten thousand or ten million, then it's hard to see how rats could.  Rats rarely live more than a year in the wild, reach sexual maturity in under two months, and so can have several generations a year.  I think that what Brian Thomas' use of "the latest and most accurate research into human genetics" has proved that all rodent species (not to mention all domestic mammals and indeed most supposedly extant mammals) are extinct, which is a somewhat problematic outcome.   I cannot help but feel that further research into population genetics, or perhaps just into the assumptions programmed into Mendel's Accountant, are warranted.

Cornelius Hunter Attacks Darwinist Metaphysics

Cornelius Hunter has, these last few days, been much better about updating his blog than I have been.  To be sure, two of his recent articles have been little more than excuses to repeat his favorite complaint about "Darwinism" -- that it is supported primarily be metaphysical, even religious, arguments against intelligent design, and his favorite confusion, between "being an explanation" and "being logically possible".  For example, in one essay, he deals with the claim that "If species had been independently created, no explanation would have been possible of this [consistent nested hierarchy]" as a claim that an Intelligent Designer would definitely not have created species whose traits were arranged in a consistent nested hierarchy.

But that is not the claim being made.  The point is that descent with modification, at least as it typically works in eukaryotes, predicts that species will be arranged in a nested hierarchy; it explains why, e.g. we find species grouped in genera and families and orders, why animals that have one bone in the lower jaw and three in the inner ear also happen to have mammary glands and a left but not a right aortic arch.  Yes, a Creator could have made separate species that way, but creationism doesn't predict such a pattern (indeed, ID proponents seem quite careful to make sure that intelligent design doesn't predict any pattern, except perhaps that we will never be able to conclusively prove that any feature is functionless) or explain why it should exist.  Certainly designers in our own experience do not design in that way.  This is less a metaphysical argument than an epistemological one, a preference for inferring known causes from their known results than in inferring unknown causes on the grounds that we can't say that the results couldn't be produced by them.  Hunter complains that evolutionists, in citing evidence for evolution, "consistently turned to organic parts and geographic distributions that make the least sense."  But that is not quite true; the parts that literally make the least sense are the parts that ID proponents crow that "Darwinists" cannot explain, such as the many problems involved in abiogenesis, that provide gaps ID proponents can stuff a Designer into.  The parts cited by Darwin and later evolutionists are the parts that make perfect sense, given common descent from ancestors that had obvious reasons for such odd traits.

Hunter makes the point that Linnaeus certainly did not think that species falling into a nested hierarchy disproved special creation, and that Linnaeus was one of the greatest scientists of his day.  On the other hand, attempts to impose Linnaean classifications to things that clearly aren't the results of branching descent with modification (e.g. orders and genera and species of clouds,  or minerals) simply didn't work as well: one can arrange any suite of objects into a nested hierarchy, but getting a single, consistent hierarchy (rather than different ones depending on which traits one selected for comparison) proved impossible for such objects.  There was something special about life, and it was something shared with suites of things (e.g. languages within the Indo-European family, breeds of domestic animals, etc.) that were derived through branching descent with modification.

Darwin's argument, and Phillip Kitcher's argument, and many other arguments for common descent, is not that a good Creator would not have made bad designs, or that an Intelligent Designer would not have made a world laced with "natural evil," it is that common descent with opportunistic modification can explain these features rather than simply accept them as the ineffable whims of a Designer/Creator.  But to Cornelius Gordon, a preference for explaining data is a religious bias when it is even acknowledged; mostly, he treats all such arguments simply as strawman attacks on Intelligent Design.  Intelligent Design is simply the position that "somewhere, sometime, Somebody did something;" insisting that the Somebody was competent, or benevolent, or supernatural, is just imposing extraneous fillips on the basic ID model (though somehow, when ID proponents are not complaining about such misrepresentations of their model, they manage to imply that ID will manage to save human dignity, fight racism, and give purpose to our lives and hope in the face of death: ID has facultative details).

Now, Hunter's latest argument is a bit different.  It deals with a recent paper by Carl Woese et al. on the origin of the genetic code.  The paper is an attempt to explain the origin of a (more or less universal -- with slight variations) genetic code in light of Woese's ideas that the original life didn't have species, that it was a community of replicating entities that freely exchanged genetic material among themselves in a truly promiscuous fashion (even more so  than modern bacteria), and were especially subject to group rather than individual selection.   Hunter's complaint, basically, is that Woese doesn't explain in detail how the ability to exchange genes arose (that is, he deals with the origins of the modern genetic code rather than with earlier stages of abiogenesis) or exactly how it works (this is in stark contrast, of course, to the detailed explanations that ID theorists provide for the origin and implementation of intelligent design).   That gene exchange, at least in bacteria, is well-demonstrated and that there are at least well-evidenced theories of how it can happen even between eukaryotes (such as plants and animals) goes unmentioned.

I'm rather hesitant to comment on Woese's paper; I'm very far from an expert on biochemistry, genetics, or abiogenesis, and do not particularly trust my competence to exegete it.  On the other hand, I can't quite help but notice that Hunter's take-away message from Woese's article seems to be that the genetic code is just a "frozen accident," something Woese is rather explicitly arguing against (and which is dismissed in Nick Lane's widely acclaimed Life Ascending, which offers a quick sketch of an attempt to explain the genetic code in terms of the chemical properties of different nucleotides, a subject alluded to in Woese's paper as well).  I'm pretty sure that Woese doesn't solve the problem of abiogenesis.  I doubt he even definitively solves the problem of the origin of a (more or less) singular, optimized genetic code.  But he does make use of known processes to move a few steps closer to such an explanation.

Hunter gets a number of interesting comments in his blog.  One of his commentators, replying to a creationist's objection (implicit in Hunter's original critique) that Woese was either oblivious or hypocritical to use an intelligently designed computer program (that simulated gene exchange in his hypothetical early community of living protocells) to argue against the intelligent design of the genetic code, noted that programs used to model and predict the weather are also intelligently designed, but this doesn't argue that thunderstorms are designed (much less designed in the same way).  This is, I think, a splendid retort to a common creationist critique of genetic algorithms and biological simulations of many types.

Sunday, November 7, 2010

AiG News to Note, November 6, 2010

Answers in Genesis' weekly roundup of science news seems a bit drab this week: creation is proved by the fact that fossils have not been found on Mars, that studies in fruit fly genetics study genetics rather than whatever AiG thinks of as information theory, that behaviorally modern humans were behaviorally modern, that a boa constrictor gives virgin birth to female offspring, and (coming round full circle) that there are plenty of planets in the universe that don't seem very hospitable to life.

The section on Martian life (or the lack thereof) is rather puzzling.  It notes a story on the National Geographic website about some scientists' best idea of where future Mars landers ought to look for signs of life or for fossils.  Alexis Palermo Rodriguez of the Planetary Science Institute in Arizona mentions various fractured basins on the planet where stable bodies of waters might have lasted for millions of centuries, and where their sediments are still likely to be accessible.  The article mentions a region in Mars' northern hemisphere named Gemini Scopuli, though it notes that a spot on NASA's list of possible future landing sites, Mawrth Vallis, also looks good.  Another scientist, Victor Baker of the University of Arizona, is quoted and comes across as cautious: he warns not to expect anything as complex as typical Cambrian fossils on Mars, though he thinks unicellular organisms are possible.

"Microorganism fossils on Mars is not too big a stretch of the imagination" is, of course, from AiG's standpoint, the credulity of "evolution-believing astrobiologists" who are convinced without evidence that life must exist on other planets (though nowhere in Baker's or Rodriguez's statements is any indication that life must exist on Mars).  AiG shows proper creationist caution: although they are convinced on theological grounds that intelligent life does not exist elsewhere in the universe, they concede that God might have created non-intelligent life on other planets.  But it is, of course, overconfident to expect to find evidence of such life.

The next section of "News to Note" covers research on fruit flies by scientists at the University of California, Irvine.  The researchers bred two populations of fruit flies, one artificially selected for long life (and slow growth and reproduction as side effects), the other bred to life fast, die young, and leave a lot of orphaned maggots.  They were trying to see which genes determined the difference between the populations, and discovered that rather than a few easily identified genes that accounted for most of the difference, found that scores or hundreds of different genes played a part even in these relatively simple differences.  From the UCI researchers' standpoint, they were settling (or at least providing some clues towards solving) a quarrel over population genetics that went back to Ronald Fisher and Sewell Wright (who favored the "lots of small changes" model) and J.B.S. Haldane (who favored the "few big changes" model).  From AiG's standpoint, they were failing to explain how "new information" (undefined, as usual) entered the genome through mutation, and illustration how evolution is impossible because genetics is really complex (that several generations of evolutionists had suspected that genetics was really complex and didn't see this as an impediment to large-scale common descent with modification does not trouble them, of course).

The next section explains how the evolutionary timeline has been confounded again, showing that evolution is wrong, that radiometric dating is worthless, and that cave men were descendants of Noah.  The confounding research was done by archaeologists at the University of Tolouse-Le Mirail in France, on artifacts dug up from 75,000-year-old deposits in a cave in South Africa.  They determined that these artifacts were made by pressure flaking, a technique for making stone tools not previously known to have been used before 20,000 years ago.

Now, it's worth noting that these were not "primitive" men.  Homo sapiens dates back to almost 200,000 years ago.  It's unlikely that the oldest H. sapiens fossils represent the earliest members of our species, since anatomically modern humans -- relatively gracile H. sapiens with chins -- are almost as old.  The makers of these stone tools were physically modern.  How behaviorally modern they were is an open question; the oldest cave paintings are perhaps 40,000 years old, and some paleoanthropologists think that language use is not much older, but again, fossils and artifacts can only show that something (e.g. art, or particular techniques for working stone) were known by such and such a date at latest, not that they could not have been known before then.  I'm unaware of any aspect of evolutionary theory that says that humans could not have invented language, art, abstract thought, and pressure flaking shortly after H. sapiens sapiens first appeared.  Answers in Genesis writers are either uninformed about the actual "evolutionary timeline" or else assume that their readers don't understand it and that the details don't matter as long as faith in Genesis is supported.

The next section is on a BBC news article that caught everyone's attention: a female boa constrictor, confirmed by her keepers to be a good girl and not at all slutty, has managed to give birth to a brood of baby boas without male help.  Given that parthenogenesis has been demonstrated before in other reptiles (famously, a Komodo dragon last year), this was not by itself a shock.  What was a shock was that the babies were all female: boa constrictors, like birds and Komodo dragons, use a WZ sex chromosome system (some other reptiles use other systems) rather than the XY system used by most mammals (and some other groups -- both systems appear to have evolved multiple times).  Since normally, in a WZ system, the W chromosome (like the Y chromosome in XY systems) is reduced and dedicated mainly to sex determination, it was assumed that WW individuals were inviable (just as there aren't humans who are YY).  All the viable babies produced by parthenogenesis of a species with WZ sex determination should be male, like the Komodo dragon babies.  But the snakes are apparently healthy WW females, which is knocking biology for a bit of a loop and giving researchers something to study.

AiG, rather astoundingly, does not declare that evolutionists being caught by surprise this way discredits evolutionary theory.  Rather, they are concerned that stories about parthenogenesis in various species will lead people to suppose that the virgin birth of Jesus may not have been a miracle (that it may not have happened at all is apparently too shocking for even an evolutionist to suggest).  They therefore end the section with a reminder that "parthenogenesis results in a near-clone of the parent -- and hence all offspring are female."  This would actually presumably be true if parthenogenesis ever occurred in a mammal, as the virgin Mary presumably was.  The authors don't seem to have quite grasped that if the virgin Mary had been a monitor lizard -- or a boa constrictor -- then it would have been quite astonishing if her child had not been a male (note to creationists: I am not in fact suggesting that Mary was a reptile).

The penultimate section of this weeks "News to Note" covers a computer model of planetary system formation that suggests that as star systems form, rocky planets several times the size of Earth and very close to their primaries (close enough to have 24-hour years) could be surprisingly common.  These planets are not expected to be very long-lived (or very habitable), but given that gas-giant-sized worlds that are very close to their primaries have been discovered, they seem plausible.  Nothing in the article in Science suggests that such "super-Earths" would be the only planets formed in their planetary systems, but Answers in Genesis notes that the existence (even the modeled existence) of numerous planets unsuitable for life in the galaxy shows just how special Earth is, and hence supports creationism (which implies that while the Earth was made to be inhabited, the rest of the hundred-billion or so galaxies and all their worlds were created just to mark seasons -- even the stars that can't be seen without massive telescopes).

This weeks summary of the news ends with a snarky mention that the Large Hadron Collider is getting ready to try to recreate conditions (in miniature) that last existed in the early stages of the Big Bang.  AiG does not seem quite clear on the difference between trying to recreate a very dense, hot state of matter and trying to prove the Big Bang, or trying to create a new universe.  They also allude to a Science Daily article on attempts to use insect fossils to estimate oxygen levels in the past, as evidence that the "pre-Flood world" had an atmosphere different from the post-Flood world we live in (which would help explain why so many of the "kinds" that God had ordered Noah to bring aboard the Ark had promptly gone extinct once they disembarked, making the whole exercise of trying to save them rather one in futility).

Saturday, November 6, 2010

John G. West Discusses Racism, Eugenics, and "Darwinism"

In an earlier post I mentioned the debate scheduled at the Charles H. Wright Museum of African American History between Intelligent Design proponents and scientists who actually do science.  The debate has since been held, and John G. West, one of the participants from the Discovery Institute, has provided his own report.  West describes the proceedings as "serious, thoughtful, and civil."

West notes that he has never claimed that Darwin invented racism, or was the worst racist who ever lived, but that his theory contributed to racism by providing a scientific rationale for it:
Despite his personal opposition to slavery, Darwin clearly believed that natural selection working on different populations produced "higher" and "lower" races with different mental capacities. Hence, according to Darwinian theory, one should expect to find races with unequal capacities. This expectation of Darwinian theory helped fuel scientific racism for decades and provided a research agenda for a number of leading evolutionary biologists, most notably National Academy of Sciences' member Charles Davenport, one of the founding fathers of modern genetics.
Now, West's analysis misses a few points.  First, given that "Darwinian theory" is notable in part for replacing the Lamarckian evolutionary ladder with an evolutionary tree, why should we expect it to yield a prediction of "higher" and "lower" races?  Given that there are no universally fit traits, how would one decide which suite of traits was "higher" rather than merely "different," and fit for a different environment?  Second, how does one get the prediction that races should differ in mental capacities?  Certainly, as far as I can tell, they might, but why ought a "Darwinian" expect such a thing?

The answer, of course, is that evolutionary theory did not prohibit such differences in mental capacities, and Darwin's contemporaries examined race expecting to find racial differences in mental traits and prepared (by a history of colonialism and slavery that had preceded Darwin's birth, to say nothing of his theory) to evaluate them as "higher" or "lower."  They assumed that their own race was smarter than others (an idea that had originated as a justification for slavery) and set out to prove it, and to fit their findings, or supposed findings, into an evolutionary framework.

West goes on:
The Darwinian connection to the eugenics movement was even more direct. Darwin thought that human beings and their capacities only arose through a merciless process of natural selection that ruthlessly exterminated the weak and the inferior. But according to Darwin, civilized societies did their best to counteract natural selection and preserve those nature would have killed off. Darwin thought that this counteracting of natural selection had serious negative consequences for the future of the human race.
I assume by "more direct" he means "less direct."  And one might suppose that if a "merciless process of natural selection" exterminated the weak and inferior, then those "savage societies" that lacked the medical means to counteract this ruthless process would end up with superior races.  That would be on average, of course: an implication of evolutionary theory is that variation exists in all populations, than new variation arises all the time (even if Darwin himself had vague and inaccurate ideas of how this happened), and that there could be no trait, on which one could base a claim of racial superiority or inferiority, that would be present in all members of one race and no members of others.  But West's argument that "Darwinism" supported eugenics would not seem to comport all that well with his argument that it implied that less technologically advanced races were "inferior" in body and/or mind.

Now, it seems to me that Darwin was subtly wrong, on his own terms, in his worries about the effects of medicine and vaccination on the overall fitness of civilized society.  By his own theory, fitness is relative to a particular environment, not an absolute, and if the environment changes, then what is "fittest" must change with it.  Vaccination, charity, etc. alter the criteria for fitness rather than cause some objective decline in it.  Here Darwin's moral intuitions (that refusing aid to "the weak" went against "the noblest part of our natures") arguably served him better than his first deductions from his own theory.

Darwin wasn't always right.  And his contemporaries, of course, were aware of this and at times eager to remind him of it.  Early evolutionists challenged Darwin on the primacy of natural selection, on Darwin's view that only minute variations were relevant to selection (rather than large-scale "saltational" changes), on his view that humans had evolved in Africa rather than in Asia, etc.  "Darwin's theory" didn't simply emerge into an intellectual vacuum and sweep all before it on the force of his own scientific authority.  People had their own ideas about human biology and anthropology, and modified evolutionary theory to fit them as often as the reverse.  The illustration accompanying this article was produced in 1857, by an author who held (at the time) to multiple independent creations of human beings, and who argued that the gap between whites and blacks was on a par with the gap between black humans and chimpanzees.  People didn't deduce from evolutionary theory that human inequality existed; they already assumed such inequality and sought new justifications for it in new theories.

Tuesday, November 2, 2010

John D. Morris Reads the Fossil Record

There are a few articles in the current Acts & Facts to cover.  One, by John D. Morris (current president of the ICR and son of its founder -- and if Henry M. Morris was "the father of modern [young earth] creationism," does that make John D. the "brother of modern creationism?"), is basically an advertisement for Morris' and Frank Sherman's new book The Fossil Record.   He states that the book was written "with Christian students in non-science majors in mind," out of concern that such students would have their faith swayed by evolutionary interpretations of fossils in biology classes or the media.  One wonders if this is a tacit admission that many of their statements would not stand up to the knowledge a science major would acquire.

Obviously, a short article is not going to provide us with the full wealth of Morris and Shermer's opus.  But in the article, Morris offers a few comments that do not fill me with confidence in his insight into the fossil record.  He states, for example:
The Fossil Record doesn’t just show how a full understanding of the fossils contradicts evolution; it specifically supports creation and the Flood. It documents the sudden appearance of basic types, not a slow development of one type from some other type through transitional fossils. Fossils exhibit stasis, not the change that evolution requires. The animals represented in the fossil record typically died in catastrophic conditions of rapid water movement, not in uniform conditions. Fossilization occurred through rapid burial. The case is strong for the creation/Flood scenario. Only a willful commitment to naturalism would lead one to conclude evolution and uniformity instead.
Note that "stasis" is a property of well-represented fossil species.  A fossil species with many specimens will show variations between specimens (just as living species do).  Some of these variations will make individuals look a bit more like species that preceded it; others will make other individuals look a bit more like later species.  But the latter sort of variations do not become more common (or the former type less common) over the duration of the species in the fossil record; the species as a whole shows no "microevolution" before being replaced by another, similar but distinct species in the same genus.  But here is the relevant point: there are observed instances of speciation.  Furthermore, the ICR (like Answers in Genesis and most other young-earth creationists) admits -- indeed insists -- that one species can change into another.  "Stasis" as the term is used by paleontologists means that the fossil record has a paucity of evidence for the very level of evolutionary change that they insist has happened!  Species well-represented enough to to demonstrate stasis, meanwhile, often themselves form transitions between genera.

And what is one to make of the claim that fossilized animals died in "catastrophic ... not in uniform conditions?"  "Uniformitarianism" means that geological processes at work in the present were at work in the past; it does not mean that the past was an unbroken succession of mild spring days.  Floods and storms and tsunamis and earthquakes occur today; a "uniformitarian" would assume that they occurred in the past (indeed, since the worst flood, earthquake, meteorite impact, etc. of the last century was probably worse than the last flood, earthquake, or impact of the last year, a "uniformitarian" would hardly be shocked at the suggestion that the worst natural catastrophes of the last million centuries were probably worse than the worst such catastrophes known from recorded history).  A herd of Centrosaurus drowning in a flooded river in the late Cretaceous is just as "uniformitarian" as a herd of caribou doing so in the last century (and that one doesn't find the "ceratopsian kind" and the "deer kind" fossilized in the same watery catastrophes hardly seems like support for a single global flood depositing most of the fossil record).

Monday, November 1, 2010

Extraordinary Mosasaur Fossil Reveals Creationist Can't Read

Brian Thomas, a science writer at the Institute for Creation Research, has an article in the current issue of the ICR's Acts & Facts.  The actual title of the article is "Extraordinary Mosasaur Fossil Reveals Original Soft Tissue."  This title is not entirely accurate.  The fossil of Platecarpus tympaniticus has matter that is "interpreted as" (one wonders how an ICR science writer would have dealt with that phrase if it had concerned, say, the 75 million year age of the fossil) compacted remains of the retina: structures that have "a morphology that is comparable to "  that of retinal melanosomes in its eye sockets.  It has a reddish splotch that is interpreted as indicating the position of the heart and liver.  Thomas notes that:

Using state-of-the-art equipment, they identified “hemoglobin decomposition products.”1 Hemoglobin is a major chemical constituent of blood. Anyone who has accidentally left meat out of the refrigerator overnight knows that it decomposes quickly. After death, hemoglobin proteins always fall apart, even when sterilized and with no water, spontaneously converting into smaller, simpler molecules.
The authors did not address the glaring question of why there was dried blood residue in a fossil dated as millions of years old. The reason is simple—they have no idea why!

But then, "hemoglobin decomposition products" are not the same thing as hemoglobin, much less the same thing as blood and actual tissue.  The fossil has chemical stains that probably indicate where blood-rich organs once were; it doesn't actually have those organs.  And while it's very rare for fossils to preserve outlines and stains indicating former soft tissue, it's hardly unheard of.  It seems rather more likely that they don't address this "glaring question" because they didn't consider it a glaring question at all: some fossils just have better soft tissue impressions than others.

Thomas introduces a quote from a different article about a different fossil -- Mary Schweitzer's stinky T. rex bones with their apparent blood vessels and reddish spots (but no actual surviving blood cells): “all of the chemistry, and all of the molecular breakdown experiments that [scientists have] done don’t allow for this" -- and concludes that this is another fossils that undermines the idea that fossils could be tens of millions rather than mere thousands of years old.  That all the physics and all the research done on decay rates doesn't allow radiometric dating to be off by about four orders of magnitude is not, of course, a point he brings up, nor does he dwell on the point that we have considerably less evidence for the mutability of radiometric decay rates than we do for the mutability of decay rates of organic compounds like hemoglobin or collagen.

Thomas closes by declaring that the fossil and its sediments are "powerful evidence" of Noah's Flood.  He doesn't dwell on the question of why, e.g. if all these different created kinds lived simultaneously, we don't find mosasaurs in the same strata as ichthyosaurs, on the one hand, or cetaceans, on the other.  Nor does he dwell on the rather puzzling question of why we don't find a lot of mosasaurs swimming off the coast today.  After all, the whole point Noah taking every kind of land animal aboard the Ark would seem to be that God did not wish any of His "created kinds" to go extinct in the flood.  Yet young-earth creationists seem to casually assume that He would not trouble to preserve dinosaurs, or cynodonts, or plesiosaurs, or the aforementioned mosasaurs, once they disembarked from the Ark or swam away from the rapidly rising mountains.  For a great many "kinds" and their constituent species, YECs have turned the Ark from a story about preservation to one about extinction.

Jason Lisle and Distant Starlight

The Skeptical Lutheran, or qpsk (I suspect that's not what his parents named him, but I'm not sure) has suggested that I examine and comment on a paper by Jason Lisle published in the Answers Research Journal of Answers in Genesis.  The paper is an attempt to solve one of the most vexing problems in young Earth creationism, the "distant starlight problem:" why, if light travels at one light year per year, and the universe is only about 6000 years old, can we see the Andromeda Galaxy, which is two million light years away, and even far more distant galaxies?

Lisle opens by noting that the distant starlight problem is, after all, very similar to the "horizon problem" in mainstream Big Bang theory: just as YECs don't quite have an explanation for why we can see distant galaxies, mainstream cosmologists don't quite have an explanation for why the cosmic microwave background is so uniform, when the universe is supposed to have been expanding faster than light so that distant regions could never have been in contact with each other.  He doesn't mention inflationary theory, though he does note elsewhere in his paper that "secular scientists" have auxiliary hypotheses that they can use to patch up the problems with their old-universe models.  More importantly, he doesn't note that the Big Bang theory isn't just some fad that caught on like bellbottoms; it explains the distribution of galactic redshifts, and predicts the cosmic microwave background whose uniformity is so puzzling.  I don't think you could really say that the "creation model" predicts the existence of galaxies most of which can't even be seen with the naked eye.

Lisle, like most modern YECs, dismisses without comment the possibility that the entire visible universe is within 6000 light years of us.  Since he gives no explanation, I can only speculate, but I suspect that he doesn't really want to argue that all those apparent galaxies (with their apparent Cepheid variables, supernovae, etc.) are really something else much closer (and if they're really what they appear to be, of course, they won't all fit within a few thousand light years of Earth).   There is one other point: if the stars were created "for times and seasons, days and years" (Genesis 1:14), it would seem fitting for those stars to be visible by the end of the creation week, when Adam and Eve first got to look at them.

He likewise dismisses the classic omphalist suggestion that light was created, already in transit, from those distant stars.  While Lisle agrees with other AiG writers that the term "appearance of age" is meaningless, and has no problem with the idea that various things from galaxies to Adam himself were created "mature," he is bothered by suggesting that God has created a false appearance of history, by, e.g. creating light from supernovae that never occurred.

At the same time, he rejects the possibility that the Earth and universe are really billions of years old and that this light has had time to reach us at 300,000 kilometers/second.  He does mention and courteously allows the possibility of Humphreys' hypothesis that time proceeds faster the  further one is from Earth (so that distant galaxies really are billions of years old), but notes that in that case, we'd expect distant starlight to be strongly blueshifted, not redshifted (unless the expansion of space were very fast indeed).  He also argues that distant galaxies are probably not very old anyway: he disputes mainstream cosmologists' suggestions for forming new stars (and hot, blue stars don't last billions of years) and for keeping the spiral pattern of galactic arms from winding up tight.

Rather, Lisle finds a possible solution in an odd fact of modern physics: it's apparently impossible to measure the speed of light going only one way: all methods for measuring it depend (explicitly or implicitly) on measuring the time it takes for light to make a round trip.  The usual assumption, of course, is that light travels at the same velocity in each direction, but it's conceivable that it travels faster in one direction and slower in another.  His suggestion is that lightspeed is near-infinite travelling to Earth from distant stars, and only about 150,000 km/sec. travelling away from Earth.   Thus, he argues, galaxies billions of light-years away were in fact created only about 6000 years ago, on day four of the creation week, and their light reached Earth only seconds or minutes later.

Technically, this is an "anisotropic synchrony convention" (ASC) for dealing with measurements of the speed of light, and is allowed under relativity theory (which traditionally has used Einstein's synchronization convention: that light has the same speed no matter which direction it's going); he's careful to note that he's not trying to come up with a radically new theory in physics.  Some of the weirder passages in Lisle's paper come from his attempts to argue that the ASC is used in the Bible and even in modern astronomy (e.g. supernovae are labeled by the year they're observed, not the year they're thought to have occurred in ... but then, this is a date for the observation, not a date for the actual explosion of the star).  The Bible, he notes, always treats light as though it moves instantly from source to observer.  Of course, over terrestrial distances, this is virtually  true.  It is not obvious at all that the Bible uses ASC rather than simply assuming that in  fact light just has infinite velocity and/or the universe is actually pretty small (e.g. those stars are fixed to the solid dome of the sky a few dozen miles over  toour heads).  Like Johnson and Humpreys, Lisle finds himself arguing that the Biblical text is really asserting something that its original readers (and indeed any reader prior to the 20th century) would never have suspected lay in the text.

The very aspect of measuring the speed of light that makes his model possible means that testing it needs to be indirect.  Lisle argues for it by suggesting that distant galaxies look as if in fact they haven't had much history: as noted, he brings up creationist arguments against forming new stars as old ones expand into red giants or go supernova, and against the possibility of natural processes maintaining spiral arms.  Despite his earlier suggestion that his model and and Humpreys' could be combined, his evidence for his model implies the falsity of Humphreys' varied cosmologies.   And of course one objection that "secular" cosmologists will have to his idea -- that it creates a favored frame of reference rather than treating all positions in the universe equally -- is a feature, not a bug, for a model designed to rescue the idea that the Earth and humanity are more or less the whole point of the universe.

One point in favor of old distant galaxies is rather quickly hand-waved away.  Quite a few distant galaxies look "old" in the sense of looking as if they have a past history.  It's one thing to be "mature" in having a panoply of stars and dust clouds and spiral arms (even if they won't last: it sometimes seems to me as if YEC vaguely denigrates the Creator, implying that He's churned out some cheap gimcrack of a universe that falls apart after a few thousand years of normal use); it seems rather another for galaxies to look, for all the world, as though they've just collided with one another (see the photo above) (note that given the size and speed of galaxies, a collision would take millions of years) or as though massive explosions have wracked their cores.  Lisle tries to argue that galaxies with massive flares of gas and dust were simply created "mature," but this is a sort of maturity analogous to trees created with ring patterns showing the effects of nonexistent droughts, fires, and lightning strikes in nonexistent centuries past, or of Adam being created with healed scars from nonexistent past injuries.  Whether or not distant galaxies look old, quite a few of them look very experienced.  It's very, very hard for YECs to avoid invoking, at some point, what looks very much like the omphalos "hypothesis" (except that, of course, by its very nature it's completely untestable).

There is one more point, brought up by Skeptical Lutheran himself and several other people more knowledgeable than myself about physics, who've examined Lisle's thesis: there are physical constants important in electronics that are dependent on light being a wave, and the performance of capicitors and magnets ought to vary as you change their position and orientation unless light waves move at the same speed in all directions.  I presume that Lisle, who seems rather bright, will eventually come up with an auxiliary hypothesis of his own to deal with this problem.  He doesn't, however, seem to have done so yet.

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.