Thursday, July 29, 2004

Nitrate Assimilation in Plant Shoots Depends on Photorespiration

That's the title of this paper, which appears in the current issue of the PNAS. The paper is based on the work of three scientists at the University of California at Davis, led by Dr. Arnold Bloom.

Papers in the PNAS tend to be rather technical, and this one is no exception. Happily, the UC Davis website has provided this readable summary of the paper's results. Here's an excerpt:

Though elegantly simple in concept, this process, known as photosynthesis, is remarkably complex in detail. And for years, researchers have been puzzled by another process, photorespiration, which seems to have annoyingly associated with photosynthesis down the evolutionary pathway.

Photorespiration has appeared to be downright wasteful because it virtually undoes much of the work of photosynthesis by converting sugars in the plant back into carbon dioxide, water and energy.

Believing that photorespiration is a consequence of the higher levels of atmospheric carbon dioxide in long past ages, many scientists concluded that photorespiration is no longer necessary. Some have even set about to genetically engineer crop plants so that the activity of the enzyme that initiates both the light-independent reactions of photosynthesis and photorespiration would favor photosynthesis to a greater extent and minimize photorespiration.

The result, they have thought, would be more productive crop plants that make more efficient use of available resources.

But the new UC Davis study suggests that there is more to photorespiration than meets the eye and any attempts to minimize its activity in crop plants would be ill advised.

“Photorespiration is a mysterious process that under present conditions dissipates about 25 percent of the energy that a plant captures during photosynthesis,” said Arnold Bloom, a professor in UC Davis' vegetable crops department and lead researcher on the study. “But our research has shown that photorespiration enables the plant to take inorganic nitrogen in the form of nitrate and convert it into a form that is useful for plant growth.”

Fascinating stuff. Also fascinating is how I became aware of this paper: Our friends over at Access Research Network seem to think this result comes as a blow to evolutionists. Here, in its entirety, is the summary of the article provided by ARN, written by Tom Magnusun:

Photorespiration, “a biological process in plants, thought to be useless and even wasteful” and “just an evolutionary leftover” from an age when carbon dioxide was more prevalent, has been found to be “necessary for healthy plant growth and if impaired could inhibit plant growth,” according to a UC Davis study. It functions as a way to inhibit nitrate assimilation. Some agricultural scientists assumed it was an unnecessary process to be genetically engineered out of plants because it was wasteful, “But the new UC Davis study suggests that there is more to photorespiration than meets the eye and any attempts to minimize its activity in crop plants would be ill advised.”

Evolutionary presuppositions stood in the way of scientific progress. A design model would have simply tried to determine the reason for the phenomenon.

Of course, the assertion that “evolutionary presuppositions” stood in the way of this particular discovery is not even based on sound logic, much less any evidence.

What, exactly, is Magnusun alleging? Is he saying that other scientists were keen on studying the photorespiration system in plants but were discouraged from doing so by that dogmatic, Darwinian thought police the ID's are always warning us about? Is he saying that in some way the uselessness of the photorespiration system is a prediction of evolutionary theory? Is he implying that evolutionists should be disappointed that the photorespiration system performs an important function in plants?

In reality, the expectation is just the opposite. The photorespiration system is complex and consumes a considerable amount of the plant's resources. Prior to the present research, it seemed that the primary function of this system was harmful to the plant (in that it seemed to undo much of the work that photosynthesis did). If the photorespiration system did not also perform some useful function for the plant then it is hard to believe that natural selection would have kept it around and functional for so long. Far from being a blow to evolutionists, this work provides a plausible explanation for why this system persists in plants.

I e-mailed Dr. Bloom and showed him the description of his paper that appeared at ARN. He was kind enough to send me the following reply:

I do not have extensive experience with the “intelligent-design theory,” but our results are not at all in conflict with evolutionary theory. What we found is that the process of photorespiration is associated with nitrate assimilation, so that conditions that inhibit photorespiration interfere with the ability of a plant to convert nitrate into organic forms of nitrogen. The statement on the web site that states “It (sic. Photorespiration) functions as a way to inhibit nitrate assimilation.” is incorrect. Our studies reveal a previously unrecognized function for photorespiration, and may provide an evolutionary explanation for why the process of photorespiration has persisted in most plants despite dramatic changes in the composition of the Earth's atmosphere.

There is one other curious thing about Magnusun's summary. He is explicitly committing the ID folks to the proposition that every part of every organism serves some useful function for the organism. I suspect every working biologist has his own catalog of favorite examples of poor engineering in nature. Perhaps Magnusun would like to get started on an explanation for, say, the useulss eyes of certain cave-dwelling rodents or the pelvic bones in snakes.

This paper is not an example of evolutionary presuppositions standing in the way of scientific progress. But it is yet another example of ID folks misrepresenting the scientific literature for the purpose of folling nonscientists.

Wednesday, July 28, 2004

Blob Mystery Solved

Don't miss this amusing article from today's New York Times. It concerns certain mysterious, er, blobs that have been washing up on beaches for over a century:

These beasts often have enormous mouths and needlelike fangs. Their names say everything - dragon fish, devilfish, viper fish, gulper eels, blacktail netdevils, ghost sharks. And then there's the repulsive triplewart seadevils, covered with spines and furrows and warts, their large mouths set in a perpetual frown.

But they all seem tame compared to the mysterious whiteish blobs that for decades arose from the sea and from time to time washed ashore on beaches across the world. What were they? They could be anything.

For more than a century, scientists and laymen who examined the tons of that protoplasm filled in the glaring gaps in knowledge of blob anatomy by imagining eyes, mouths and slimy tentacles long enough to sink cruise ships. Warnings were issued. Perhaps the blobs were remnants of living fossils more fearsome than the dinosaurs.

In 1972, a jittery analyst wondered if one particularly enigmatic blob was the decomposing body of a giant alien from outer space.

Well, the mystery has been solved. And - surprise! - the blobs are not decompsoing alien bodies:

But now a team of six highly skilled, if somewhat whimsical biologists centered at the University of South Florida has applied DNA analysis to the blobs and, alas, solved the mystery. The answer is all too mundane: The blobs are old whale blubber.

“To our disappointment,” the scientists wrote last month in The Biological Bulletin, “we have not found any evidence that any of the blobs are the remains of gigantic octopods, or sea monsters of unknown species.”

Richard Ellis, author of the 1994 book Monsters of the Sea, an exploration of some of the world's most bizarre fauna, called the DNA finding convincing and devastating.

Tuesday, July 27, 2004

Sisson, Part Three

I will now resume my critique of Edward Sisson's contribution to William Dembski's anthology Uncommon Dissent.

Sisson gives almost no consideration to the evidence in favor of evolution, but he does comment briefly on the fossil record:

But 150 years of investigation into the layers of the earth has not revealed the predicted trnasitional forms. In other words, the “sonar beams” have not found the “land bridge”. Scientists looked beneath the “sea” (the dirt) but the “land bridge” (the transitional forms) was not there. (I now some evolutionists say that the fossil record is sufficient, and every month or so the popular press reports on some obscure fossil discovery that supposedly is evidence of unintelligent evolution. The other contributors to this volume have convincingly refuted that assertion, however - see, for instance, Michael Denton's Evolution: A Theory in Crisis.)

I will explain the references to sonar and land bridges in my next posting.

I'm sure Sisson is aware that virtually every plaoentologist in the world would defend the proposition that the fossil record is entirely consistent with evolutionary expectations. Sisson feels no need to consider their arguments in any serious way, preferring instead to take the word of a single biochemist (Denton). And he's accusing scientists of accepting a low standard of evidence?

Let's take a moment to consider why the fossil record provides such compelling evidence for evolution. A fossil is essentially a snapshot of the fauna that existed in some earlier period in Earth's history. It tells us that an organism having particular characteristics existed at a certain time. Now, if common descent is true, and if the phylogenies inferred from genetic and anatomical considerations are correct, then we can make certain definite predictions about what sorts of animals existed during what time periods.

This is a test evolution passes easily. We can say, for example, that if common descent is true, then the earliest creatures to appear on Earth should also be the simplest. We should find fish appearing before amphibians, which in turn should appear before reptiles. And so on. In other words, the hypothesis of common descent implies that there was a definite order to the appearance of different animals on Earth. The fossil record bears out this prediction. Just one fossil out of place would be enough to cast serious doubt on common descent, but no such fossil has ever been found.

ID offers no explanation for the fossil record. The young-Earther propose that the sequence of fossils represents the differing abilities of animals to avoid the rising flood waters in the time of Noah. I believe that explanation is preposterous, but at least they recognize that there is some phenomenon to be explained.

The second way the fossil record provides evidence for evolution is by providing clear examples of transitional forms. The transitions from reptile to mammal, bear-like mammal to whale, and from australopithcine to human are especially well-documented, as are the fossil histories of horses, rhinos, elephants and many other species.

All of this means nothing to Sisson. We don't even know how he responds to the readily-available facts I just cited, since he doesn't bother to tell us.

He does give us a hint, though, in the following statement:

Science expected to find sequential layers of gradually changing forms, which would confirm the fact of descent with modification (although the fossils, being stone versions of hard body elements auch as bones, would not provide direct proof of the genetic mutation process or that the process was unintelligent and natural). (P. 81)

So it seems that Sisson feels he can dismiss the fossil record as evidence for evolution because it provides few (though not zero) examples of gradual change. Science expected to find such examples, you see. What Sisson omits is that the prediction of “insensibly graded” forms, to use Darwin's phrase, was made at a time when there was no clear understanding of the fossilization process, no good estimate on the age of the Earth, no understanding of the mechanisms of heredity, and no clear theory about the nature of speciation. Once those holes are filled in it becomes clear that Darwin's theories do not imply that series of insensibly graded fossil forms should be found. That was simply a wrong prediction. That is precisely the point Gould and Eldredge were making with their theory of punctuated equilibrium.

Sisson, like all anti-evolutionists, refuses to make the slightest effort to understand PE. He writes:

Advocates of neo-Darwinism, punctuated equilibrium, or of similar theories under other labels, all assert that chance combinations of atoms and molecules, primarily in DNA, given several billion years in which to operate and to be selected, not only can but in fact have given rise to all of the diversity of life we see today.

Of course, punctuated equilibrium is not a theory separate from neo-Darwinism, and it has nothing to do with the mechanisms of evolution. Rather, PE is merely a description of the consequences of Mayr's allopatric model of speciation for the fossil record. As Gould and Eldredge have pointed out (and this aspect of their work is uncontroversial), given the allopatric model we should expect to find periods of relatively abrupt change followed by periods of stasis, just as we do find.

No doubt Sisson would dismiss that as special pleading. He would do that not because the argument is wrong, but because it is easier than actually analyzing the facts of the matter.

Sisson also has some thoughts on the nature of genetic mutations:

Today, the “land bridge” most strenuously advanced as evidence that the generation of new species results from descent with modifications caused by natural, unintelligent, random processes is the mutation of germ cell DNA that supposedly causes beneficial changes in body forms and structures. Technologies sufficient to conduct the investigations into such mutations - the “sonar” that allows this theory to be tested - are fairly recent, but have been around long enough that of the trillions upon trillions of mutations said to have led to all of the genes in all living things, science shold have found proof of a large number of such mutations by now. But it does not appear that even one such beneficial mutation in germ cell DNA that caused a change in body form has been identified. (P.81-82) (Emphasis in original).

Golly! Not one beneficial mutation? Shall we take bets on how many geneticists would agree with Sisson's comment here?

With the exception of neutral mutations, every mutation causes a change in body form. Whether a mutation is beneficial or not will depend partly on the environment in which it occurs, but there are certainly plenty of beneficial mutations that have been documented.

It is possible that what Sisson has in mind is a mutation that causes a large change in the resulting phenotype of the organism. These are not hard to find either, however. It is well known that mutations in Hox genes can cause precisely the large effects Sisson seeks. One especially important example of this phenomenon is described in this short article. The idea that no such large-scale mutations are known is sufficiently absurd, that it effectively eliminates Sisson from deserving serious consideration.

Nonetheless, let's look at what he says next. Picking up where the last quote left off, we find:

The scientific establishment tells us regularly that evidence of beneficial genetic mutation is everywhere, that the development of pesticide resistance by insects, antibiotic resistance of bacteria, or beak-length changes in Galapagos finches caused by drought conditions are all examples of evolution, in which a few individuals develop new features in their DNA to combat a “selection event” that causes a mass die-off. (P. 82)

If this essay were an example of the normal, run-of-the-mill ID stupidity I would assume that Sisson is building up to the standard argument about microevolution vs. macroevolution. Sisson, staying true to form, is building up to something far sillier. We continue:

But all these processes are merely natural variants of breeding, such as that which has been conducted by humans for thousands of years. In every population under study, be it cockroaches under attack by the Orkin Man, bacteria under attack by a doctor, finches suffering because of a drought, or wooly sheep in a breeder's flock, an external event - be it pesticide, medicine, drought, or the preferences of human farmers - causes individuals that have certain traits to die without reproducing, letting others that already have certain other traits reproduce more offspring. Those offspring that also have those traits are in turn able to consume the available food and other necessities of life (whether provided by nature or by the breeders) that otherwise would have been denied to them (either because it was consumed by the offspring of the prematurely deceased indivudals, or was withheld by the breeders). (Emphasis in original) (P. 82)

Now, I know what you're thinking. You're asking yourself “He's not really about to argue that the naturally occurring variation in populations originates in some way other than mutation?” Read on, but first put a soft cushion in front of your keyboard. Your jaw is about to hit the desk. Hard.

What has happened in each instance is that a gene that was present in a smaller proportion of the population before the environmental or breeding condition occurred is now carried by proportionally more (and in total numbers more) offspring than would have been the case had the condition not occurred. Further selective pressures - be they continual application of pesticides, medicine, drought, or breeding preferences - lead to a further focus on those particular traits - traits that were still, however, derived from genes that already existed in the population prior to the first appearance of the condition that caused the selection process to begin. From the perspective of the creatures, whether being bred or naturally selected, the operation of the process is identical. This process is often referred to as “microevolution” althouth there is no actual mutation of any gene at all. (Emphasis in original) (P. 82)

So let me get this straight. He's conceding that large quantities of variation exist in natural populations and he's conceding that sustained selection pressure can cause these changes to accrue to the point where noticeable changes in the population occur. The objection is that we can't be sure that these variations arose via mutation? If anyone reading this believes I have misinterpreted Sisson, please let me know.

Now, I assume that he's using the term 'mutation' as a blanket term to include any well-understood mechanism that causes the offspring's genome to differ from that of its parents. That would include recombinations and duplications, among other mechanisms. Somehow I don't think Sisson is protesting that scientists have misevaluated the relative importance of mutation and recombination in evolution.

Assuming that's correct, is Sisson aware that the gene is the unit of heredity? That it is the genes and the genes alone that get passed on from parent to child? That, ultimately, every aspect of the organism's phenotype is under the control of the genes and that changes in the genes can lead to changes in virtually any aspect of the organism? Where does Sisson believe all this variation comes from if not through changes in genes?

And then there's the style of these two paragraphs. The first begins with the statement, intended to contradict the examples of evolution cited in the previous paragraph, “But all these process are merely natural variants of breeding...”. At the end he explains that from the perspective of the animal there is no difference between natural selection and breeding. He presents this as if this connection is something he discovered; like its something evolutionists have overlooked.

Which is pretty funny when you consider that Darwin devoted the entire first chapter of The Origin to the subject of breeding. He did this for the specific purpose of making his later arguments easier to understand. Of course the continued working of natural selection is analogous to what breeders do. That's the whole freakin' point!

Here's one more bit of Sissonian insanity:

The central problem for the theory of unintelligent evolution is that it asserts that the state of life on earth that existed billions of years ago exhibited very few genes, which the theory must connect with the current state of life, in which there are trillions of genes. The theory implies, but does not ever really try to prove, that the dates the supposed mutations occurred have some timing connection with the dates of population die-offs and the appearance in the fossil record of new body forms. But analysis of the prehistoric dates of die-offs and of population increases in fact tells us nothing about when the genes we see today first came into existence, nor of how they came into existence. The evidence of breeding disproves the assumption that there is any timing link at all between the date a gene (that produces a noticeable new body form) first appears in the gene pool of a species and the date by which creatures that exhibit the body form produced by that gene have become so numerous that science notices the appearance of that new body form in the fossil record. (P. 83)

I give up. If you don't find that paragraph to be obviously stupid, then I doubt any argument of mine will convince you that it is.

And I apologize for quoting Sisson at such length, but I don't want you to think that I am somehow taking his statements out of context.

In this book I was supposed to find the thoughts of intellectuals who find Darwinism unconvincing. Instead I find a group of people who, in Medawar's memorable phrase have been “educated beyond their ability to undertake rational thought”. Perhaps the remaining essays in the book will include at least one paragraph that's not completely idiotic. I'm not holding my breath.

Monday, July 26, 2004

Mutation Bias?

Have a look at this short review of the new book Biased Embryos and Evolution by Wallace Arthur. The reviewer is Armond Leroi, a British biologist.

I mention this book for two reasons. The first is that Leroi praises the book as a good, clear introduction to the subject of evo-devo, one comprehensible to non-biologists. Personally, I've been looking for such an introduction for a while now, and I will probably pick up a copy of this book eventually.

The other reason is that Arthur apparently discusses the idea of orthogenesis. This refers to the possibility that evolution is effectively channeled into certain directions via design and developmental constraints. If this is true, then the trajectories traced out by evolving populations are not as random as is commonly thought. Such a discovery could also provide a compelling explanation for evolutionary convergence.

Orthogenesis has been very unpopular among scientists since no one has proposed a plausible mechanism by which it happens. Arthur seeks to change that. Here's Leroi summarizing Arthur's argument:

These are brave words. Orthogenesis has been a cause without mainstream sympathizers for at least 60 years. The reason for this is that no one has provided a mechanism by which it might work. Most biologists believe that the evolutionary direction of lineages is largely determined by natural selection; a minority make great play of contingency (the non-selective effects of meteor strikes and the like). So what is going on? Has Arthur discovered a new principle of evolution?

Not really, no. The fuel in his orthogenetic engine is 'mutation bias'. Mutation produces novel phenotypes, but it does not produce all novel phenotypes in equal frequency in a given population. For example, mutations that cause an animal to become smaller than normal might be more common than those that cause it to become larger. This bias is the result of the way body size is specified in development — a bias that might influence the direction that evolution takes, causing small animals to evolve more often than large ones.

And later:

Mutation bias is not enough to produce orthogenesis, however. If there is a single fitness optimum, or if the population is sufficiently large to ensure that all possible mutations are always present, then the direction of evolution will be dictated by natural selection alone. But if the landscape is rugged and population sizes small, the particular peak climbed by a population could depend on what mutations happen to be available. This is not orthogenesis of old — which posited a force independent of, or even capable of opposing, natural selection — but a reassignment of influence over evolutionary trajectories from natural selection to the kind of genetic variation available for it to work on.

If 'mutation bias' turns out to be a new term for an old idea, the same seems to be true for another unusual term: 'internal selection'. This is the idea that as one part of an organism evolves, it exerts selective pressure on other parts to change as well. Suppose a mutation increasing the length of an animal becomes fixed in a population. This might cause the subsequent fixation of another mutation that increases the animal's width, so restoring an original, harmonious, proportion. Arthur makes great play of this, but I think the interaction at the heart of this process is well known to population geneticists as 'fitness epistasis' and has often been experimentally demonstrated.

Leroi's conclusion is that Arthur's ideas are interesting, but far from proved.

I mention this here because, if Arthur is correct and mutation bias does lead to certain evolutionary pathways being favored over others, then this throws yet another monkey wrench into William Dembski's scheme for inferring design in organisms. Remember, Dembski's key ideas are that if an object is highly improbable and conforms to some independently describable pattern, then we can conclude it was designed. As has been documented elsewhere, his whole system is shot through with holes. But one of the biggest is his claim that we can carry out meaningful probability calculations regarding the formation of complex, biological structures.

Arthur's ideas would have to be taken into consideration in any such calculation. If certain sorts of phenotypes are more likely to be found in a population than others, than this will effect our measurement of how likely it is to evolve a particular complex system. And unless we can quantify very precisely which sorts of mutations are more likely to be found than others, it will be effectively impossible to carry out any such computation.

The evolution of complex systems dempends on far more variables than can possibly be captured in any elementary probability calculation. Arthur's ideas, if correct, would make that problem even more acute.

I, Robot

I went into this film with very low expectations. I saw it mainly because Isaac Asimov is pretty high-up in my list of personal heroes. I'm also something of a Will Smith fan. And, c'mon, robots!

Actually, the movie was a pleasant surprise. It bears little resemblance to anything Asimov ever wrote (the story owes far more to Jack Williamson's novel The Humanoids) but it's far more intelligent than most science fiction movies. Faint praise, I know. The action sequences are very well done, and the robots look fabulous. Recommended.

Sunday, July 25, 2004

Rivera on Altruism

When last we saw Breakpoint science commentator Roberto Rivera, he was explaining to the world why Darwinists should be completely indifferent to the looming extinction of the giant panda. The panda is simply the loser in the game of natural selection, you see. His argument there was completely undone by his failure to make the elementary distinction between “is” and “ought”. Science can tell us what actually goes on in nature, but it tells us nothing about morality or proper conduct.

Now Rivera is back with a new column. This time his target is altruism.

Altruism has long been a topic of discussion among evolutionary biologists. The problem is: If natural selection only favors the immediate reproductive success of individuals, then how can altruistic behavior (in which an individual assumes some risk to himself to help some other organism) evolve? In resolving this dilemma, it's important to realize that biologists have a precise, technical definition of altruism in mind. Organism A is behaving altruistically toward organism B if it is increasing B's chances for reproductive success at the cost of its own. There is no implication here about A's motives, and certainly no consideration of the morality of A's actions. We will be returning to this point later.

The solution to this dilemma lies in the idea of kin selection. Very briefly, the thing to tealize is that it is genes that actually get selected by natural selection. Further, there are copies of your genes residing in your close relatives. Consequently, in aiding your close relatives to survive and reproduce, you are also encouraging the spread of many of your own genes. This notion can be mathematized and tested against nature's data. It has proven to be a very fruitful explanation for many instances of altrusitic behavior.

What about instances of altruistic behavior where A and B are not closely related? A second sort of explanation comes into play here: Reciprocal Altruism. The idea is that in animals that live in large, social groups, altruistic behavior can be favored by selection if the altruism is repaid at some later date. “I'll scratch your back if you scratch mine” as the saying goes. Once again, there is no discussion of morality or motives here. We're talking about the spread of genes that lead to certain sorts of behavior.

So what's Rivera's problem with this? Immediately after a lengthy paragraph in which he provides a tolerable explanantion of kin selection (though he does, incorrectly, refer to it as “inclusive theory” when he really meant something like “the theory of inclusive fitness”), he writes:

Still with me? If all of this sounds less than, well, altruistic to you, you’re right. The problem with books like Mock’s and the entire field known variously as evolutionary psychology or sociobiology isn’t that they get God wrong ? He is rarely, if ever, mentioned ? it’s that they get man wrong. The portrait of man that emerges from the pages of Mock’s book and others such as Steven Pinker’s The Blank Slate: The Modern Denial of Human Nature is scarcely recognizable to anyone who has encountered man as he actually is. The analogies to honeybee proto-queens and other animals ignore the marked differences between human and animal behavior, differences that aren’t a matter of degree but of kind. The royal misdeeds Mock mentions are remembered today as negative examples, not as something to be emulated. They’re seen as a betrayal of their perpetrators’ humanity, not as a fulfillment of it.

Alatawuané icas imani'u. Barletas e'e barkia'a. Pro'e lai e'le a pantou la'u. Ilei pandera zel e' tomu pere no mo mai. Likewise, terms like “reciprocal altruism” aren’t only oxymoronic, they’re unjust. They shortchange the real sacrifices people make on behalf of their families and loved ones. They cannot begin to account for the tenderness expressed in the words at the beginning of the piece and of this section. It’s a folksong from the Solomon Islands, “Sweet Lullaby,“ in which a sister consoles her younger brother after the death of their father and promises to always take care of him.

The book by Mock being referred to here is More Than Kin and Less Than Kind: The Evolution of Family Conflict, by Douglas Mock of the University of Oklahoma (and not Oklahoma University, as Rivera incorrectly identifies it elsewhere in his essay).

Rivera's error is easy to spot. He is using the term “altruism” in its everyday sense, with all of its usual moral connotations. Scientists like Mock and Pinker are using it in its technical sense. Similarly with reciprocal altruism. It is neither oxymoronic nor unjust. It is a term used to describe certain sorts of behavior found in among social animals.

With that simple realization, Rivera's whole agrument collapses.

Mock and Pinker are not shortchanging anyone's sacrifices for the simple reason that such sacrifices are not under discussion. Human beings are capable of such sacrifices because we have big brains and culture. That makes it possible for us to overcome the cruelty of natural selection. Most animals lack both of those features. There is nothing in the literature of sociobiology or evolutionary psychology to challenge this.

Pinker and Mock are simply arguing that, intelligence and culture notwithstanding, there are certain aspects of human behavior that are best explained by coming to terms with our evolutionary history. That there are other aspects of human behavior not well explained that way is neither here nor there. Read their books for the details.

Rivera is engaging in two standard tricks of creationist argumentation. First, he suggests that facts that are obvious to any lay person are somehow not obvious to scientists. Second, he accuses scientists of cold-heartedly trying to reduce humanity to a few easily grasped principles. Consider Rivera's conclusion:

What is man, that Thou dost take thought of him? And the son of man, that Thou dost care for him? Yet Thou hast made him a little lower than God (Elohim), and dost crown him with glory and majesty! That we see these actions as not only noble but also human ? regardless of our ability to live up to these standards ? belies the reductionism inherent in accounts like Mock’s and others. This matters because if I had to name one enemy we should be wary of, it wouldn’t be militant atheism or moral relativism. It would be reductionism. We’ve just completed a century in which ten of millions died in the name of one reductionist creed or another. B.F. Skinner may have named his magnum opus Beyond Freedom & Dignity, but he was hardly unique in creating a limited view of what it means to be human. In the last century nearly everyone tried to cut humans down to a manageable size — economic man, democratic man, sexual man, racial man — anything but the maddeningly flawed, complicated, god-like creature described by the Psalmist. (Emphasis in Original)

Inherent reductionism? Huh? In a scientific context, the term “reductionism” is not well-defined, but basically refers to the idea that large complicated objects are best understood by breaking them down to their component parts and studying the parts instead. Philosophers have been known to get into heated disputes over the importance of reductionism to science.

But that is not the sense Rivera has in mind (if it is, then I can't imagine what his point is here). Rather, Rivera is accusing Mock and Pinker (and their ilk) of trying to reduce humanity to something overly simple. Since they are doing no such thing, a fact obvious to anyone who has seriously tried to understand their arguments, his accusation is simple nonsense.

Once again Rivera has completely embarrassed himself by failing to make an elementary distinction (is vs. ought in his panda article, and techinical vs. everyday meanings of terms here). Yet he writes with the sort of breezy self-assurance and implied moral superiorirty that only the deeply ignorant ever attain.

Sometimes I envy people like Rivera for their ability to write, with no evident sense of shame, on subjects they know nothing about. Mostly, though, I think he's an asshole.