Tag Archives: evolution

The Evolutionary Foundations of Dog Behavior.

[Notable New Media]

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes frequently to Skeptic as well. He can be contracted at krausekc@msn.com.

Border collie "eye" rule.

The Border collie “eye” rule.

Ethologists like Mark Feinstein and Raymond Coppinger attempt to study animal behavior objectively by emphasizing its biological foundations. In their new book, How Dogs Work, the authors scrutinize, for example, the adaptive motor-pattern foraging sequences of both dogs and wolves.  In all such species, different patterns—not learned, but genetically based—emerge at different stages of life.

When born, both dogs and wolves demonstrate a characteristic mammalian neonatal foraging sequence: orientation (toward mom) > locomotion (to mom) > attachment (to her teat) > forefoot-tread (stimulating lactation) > suck. Here, the pups’ mouths and digestive systems are well-adapted to challenges imposed by the foraging environment—that is, mom.  But despite the close evolutionary relationship between dogs and wolves, puppyhood is the point after which foraging parallels end.

Adult predators exhibit the following generalized foraging pattern: orient > eye (still, with gaze fixed and head lowered) > stalk (slowly forward with head still lowered) > chase (full speed) > grab-bite (disabling the prey) > kill-bite > dissect > consume. But some species, and some individual dogs and wolves, might substitute one element, or “rule,” for another.  Coyotes that tend to hunt small prey, for instance, might occasionally substitute the forefoot-stab rule for the chase rule, and the headshake rule for the kill-bite rule.  Large cats like the puma, by contrast, might substitute the forefoot-slap rule for the grab-bite rule in order to bring larger prey down from behind.

The coyote "forefoot-stab" rule.

The coyote “forefoot-stab” rule.

The form of grab- or kill-bite can vary between species as well, often based on the predator’s evolved anatomy. The puma usually kills with a bite to the neck, crushing its prey’s trachea, or to the muzzle, suffocating the prey.  But the wolf often grab-bites its prey’s hind legs, shredding its arteries and slowly bleeding it to death.  Puma and wolf anatomies—jaw structure, dentition, and musculature, in particular—apply different mechanical forces, and thus demand the evolution of at least slightly different foraging behaviors.

Domestic dogs, on the other hand, have long relied on humans for food and now rarely demonstrate complete predatory foraging patterns. Rather, different breeds have retained different partial sequences or distinct individual rules.  Border collies, for instance, are famous for following the eye rule.  I once owned an Akita that employed the forefoot-stab rule with astonishing expertise to catch mice rummaging deep beneath the snow.

Nevertheless, say Feinstein and Coppinger, “certain commonalities have long persisted in the predatory motor-pattern sequences of all carnivores, reflecting their shared ancestry” and “an intrinsic ‘wired-in’ program of rules” that at least partly governs their foraging behaviors. Learn much more about why our beloved pets and working partners really behave in the ways they do in the authors’ fascinating new work, How Dogs Work (University of Chicago Press 2015.)

How Dogs Work

Time to Rethink Omega-3s?

[Notable New Media]

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well.  He may be contacted at krausekc@msn.com.

Nutrition researchers have long touted the heart-health benefits of Omega-3 polyunsaturated fatty acids, typically found in wild oily fish and flaxseed, for example.  General recommendations to consume foods rich in Omega-3s and even to supplement with fish oil derived in part from evidence showing that the cold-climate Inuit, for example, have persisted quite healthfully–that is, with a low incidence of cardiovascular disease–on traditional marine diets rich in fat, especially Omega-3s.  The inference was that the Omega-3 fatty acids were protective against heart disease, perhaps because they lowered LDL and raised HDL cholesterol levels in the blood.

But do such benefits accrue to all human populations more or less equally?  Perhaps not.  In a study recently published in Science, researchers scanned the genomes of 191 Greenland Inuit (formerly known as Eskimos, whose ancestors had lived in the Arctic for thousands of years) and compared them to the genomes of 60 Europeans and 44 Han Chinese.  What did they find?  The native Greenlanders had developed special mutations to genes involved in fat metabolism (fatty acid desaturases) that likely evolved through natural selection to help counteract the effects of a diet high in fat, mostly from seals and whales that consume oily fish.

According to these researchers, that 100 percent of the Inuit, but only 2 percent of the Europeans and 15 percent of the Chinese, possessed these adaptations implies that, on average, members of each population might synthesize Omega-3s very differently from members of the other populations.  In other words, one group’s unique evolutionary adaptations–in this case, to cold weather and a traditional, high-fat diet–might render them an inappropriate population upon which to base nutrition advice to the general public.

But those who take personal health seriously already knew better than to receive generalized nutrition advice as gospel.  First, as I’ve argued more than once before, nutrition science is inherently volatile.  Myriad confounding factors, difficult to isolate and measure, often make it nearly impossible for researchers in this field to offer concrete advice.  Second, for many reasons, every individual requires a personalized diet and exercise plan that also evolves as the individual grows older and as continuing and disciplined personal experimentation (that is, science) reveals his or her special health and performance needs.

Undeniably Nye.

[Notable New Media]

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well.  He may be contacted at krausekc@msn.com.

In Undeniable: Evolution and the Science of Creation (St. Martin’s 2014), recently-celebrated creationist debater, Bill Nye (“the Science Guy”), has collected a few dozen frustratingly brief essays on a wide variety of scientific topics with special emphasis, of course, on evolution.  Undeniable could inspire very casual readers of full-length non-fiction–if such creatures really exist.  But it might disappoint certain others.

I can’t help but conclude that Nye’s primary motive was to cash in quickly on his recent popularity among science literates and left-leaning political ideologues.  Which is absolutely fine–better him than Oprah’s spawn, for example.  First, he includes precious few references that discriminating and truly curious readers not only crave, but require.  Second, Nye’s opinions on GMOs, for example, were apparently premature.  Indeed, he changed his mind around February of this year, shortly after his visit to Monsanto’s headquarters.  “GMOs are not inherently bad,” he finally concluded in an interview with HuffPost Live. “We are able to feed 7.2 billion people, which a century and a half ago you could barely feed 1 and a half billion people and [it’s] largely because of the success of modern farming.”  True, but why would that fact surprise anyone, let alone Bill Nye?

In any case, Nye remains an exceptional science communicator, perhaps because of his wonderfully geeky bow-tie, or maybe because he claims to empathize with the many religiously-abused deniers of evolution–including his debate opponent, Ken Ham, who still insists that the Earth is no more than 6000 years old.  Nye understands “the troubling nature of the shortness of our lives,” for instance.  But human mortality can either “make you want to listen to old country western songs about how miserable life can be,” he says, “or it can fill you with joy.”

I don’t know about any of that–mortality is a pretty tough nut to crack, regardless of one’s musical tastes.  But Nye’s certainly correct that humans as a species–most individuals excluded, of course–have made great strides in comprehending the objective truths of our existence in just the last 150 of our 100,000 total years on planet Earth–thanks to the methods of science.  “Think what lies ahead for our species,” he prescribes hopefully, “if we preserve biodiversity and raise the standard of living for everyone.”  That could be great, I suppose–depending.  But maybe a great deal to ask of a species whose adult members continue to think of “science” as merely a subject they studied (or not so much) in school.

Book Review: Kim Sterelny, Dawkins vs. Gould: Survival of the Fittest (Cambridge, UK: Totem Books 2007). 205 pp.

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well.  He may be contacted at krausekc@msn.com.

All too often lost among the mind-numbing, carnivalesque creationist-vs.-evolutionist sideshows currently haunting the pop media’s pseudo-intellectual backwaters are the genuinely scientific debates over evolution’s varied mechanisms and alleged limitations.  What is the fundamental unit of evolutionary change?  Is the process dominated by natural selection, developmental constraint, or chance?  To what extent can selection explain and predict cultural and psychological phenomena?  No questions could be more relevant to, among other things, a competent understanding of humanity—who we are and what we can reasonably expect from one another.  And these are precisely the questions presented and debated among science’s most prolific authorities in philosopher Kim Sterelny’s updated edition of Dawkins vs. Gould.

Oxford zoologist, Richard Dawkins, and recently deceased Harvard paleontologist, Stephen Jay Gould, of course, agreed more than disagreed on almost every aspect of evolution.  Dawkins, for example, never proposed that the effects of natural selection were limited to gene frequencies.  Nor has he denied the essential role of organisms.  Instead, Dawkins pointed out that because adaptations result only from extended series of small changes, the basic agents of evolution must persist over extended periods of time.  At the organismal level, however, sexual reproduction is not the same as duplication.  Only the gene (defined in The Selfish Gene as “any portion of chromosomal material that potentially lasts for enough generations to serve as a unit of natural selection”) is significant enough to cause change, on the one hand, and small enough to escape DNA recombination, on the other.  Only gene lineages, in other words, possess histories deep enough to serve as the fundamental units of natural selection.  To the organism, Dawkins relegated the substantial but secondary role of “survival machine” for genes or, more accurately, gene alliances.

Gould’s view was more traditional in Darwinian terms and perhaps more intuitive.  Although he acknowledged the fact of selection at the genetic level, for him such was the exception to the general rule that evolution mostly acts upon organisms in local populations, or even on groups of organisms including species and clades (founding species and all their descendents).  Genes more record the process than cause it, Gould argued, and their survival relies not simply on alliances with other genes, but more profoundly on various features of and modifications to the organism’s larger environment.

Dawkins, however, has alluded to at least two general phenomena demonstrating the considerable weakness of any organism-centered view of evolution.  “Outlaw genes,” for example, rather than allying with other genes, appear to compete against them—potentially at the expense of the host organism’s fitness.  Consider mitochondria, for example, which are inherited only maternally.  Certain plants that are normally capable of producing both pollen and seed will occasionally develop “sex ratio distorter genes” causing organisms to produce only mitochondria carrying seed.  Any mutation to such genes rendering daughter-making more likely would be favored, everything else being equal.  Similarly, so-called “segregation distorter genes” will chemically sabotage the allele with which they are paired on the chromosome, even if it results in a less fit—in this case sterile—organism.

Other genes promote themselves by reaching beyond the organism’s physical margins.  Recently, in The God Delusion, Dawkins reiterated how this works from the perspective of a living extended phenotype.  “An animal’s behavior” he writes, “tends to maximize the survival of genes for that behavior whether or not those genes happen to be in the body of the particular animal performing it.”  The classic example involves a parasitic brainworm that burrows into the head of an ant, causing it to climb toward the most exposed portions of leaves and blades of grass until a cow, the worm’s ultimate host, consumes it.  Although the relevant genes reside in the parasite, their adaptive effect takes place in its host.  Instead of adapting the organism to the environment, in broader terms, extended phenotype genes adapt the environment to the organism.  As such, neither outlaws nor extended phenotypes can be comfortably fused into an organism-centered view of evolution, and for Sterelny, Dawkins’ reductive selfish gene theory of natural selection is therefore the more sustainable one.

But Gould, of course, de-emphasized the consequence of natural selection in the first place.  For example, although both he and Dawkins recognized the supply of variation as a constraint on the evolutionary trajectory of any given population, Gould conceived of developmental biology as a brake on creativity or as an entrenchment of evolutionary patterns and features.  Consider, for instance, Wallace Arthur’s study of two centipede families.  Each of the 1000 or so species of Geophilomorphians display an odd number of body segments (every one of which has a pair of legs), though that number ranges outrageously from 29 to 191.  A similar diversity of Lithobiomorphian species all have fifteen segments.  Why no even numbers?  Selective pressure is an unlikely answer, given the extreme range of leg pairs among Geophilomorphians.

In his Biased Embryos and Evolution, Arthur concluded that nature is incapable of selecting a Lithobiomorphian with, say, thirty segments because these creatures’ developmental mechanisms impose an absolute constraint against it.  He pointed out as well that more relative biases in the variation reserve are sufficient to the same task.  Sterelny offers a hypothetical, initially isolated population of ringtail possums the average weight of which is two kilograms.  Comparatively sized predatory cats are introduced.  One-kilo possums can hide; three-kilo possums can successfully defend themselves.  All other factors being equal, which will be selected?  The answer, Sterelny reasons, will depend not on external dynamics, but rather on the current possum population’s developmental bias.

Consider too one of Dawkins’ own examples in Climbing Mount Improbable.  In general, shells vary in only one of three ways: their “flare” (the rates at which they uncoil in one plane), their “spire” (the rate at which they rise above that plane), and their “verm” (the rate at which their tube expands).  Such dimensions allowed David M. Raup to represent the range of all possible shell variations as a cube (dubbed “Raup’s cube”), much of which remained unoccupied by a shaded area indicating existing shell shapes.  Why so many missing variants?  Have existing shells inherited an insufficient capacity to vary, or has selection determined the outcome?  We simply don’t know yet, according to Sterelny.  But Dawkins has emphasized the revolutionary rather than the conservative character of developmental biology.  In Climbing Mount Improbable, he argued that, for the relevant lineages, the momentous invention of segmentation, for example, opened up an expansive new world of adaptive possibilities.  Indeed, segmented arthropods, including spiders, crabs, and insects, are by far the most diverse group of animals on the planet.

While Sterelny admits that “[t]he integration of evolution and development is the hottest of hot topics in contemporary evolutionary theory,” his “best current guess” is that developmental biology does indeed produce significant biases in the variation available for natural selection.  In support of his position, he points out that gene mutations involve movements, duplications, inversions, and deletions in addition to limited point mutations.  These “middle-size” mutations cause changes to gene regulation, shifts in reading frames, and thus substantial alterations to traits that might well introduce variation supply biases.  Touting his Ontogeny and Phylogeny as a “foundation of modern evolutionary developmental biology,” Sterelny predicts that Gould’s position in this regard “will probably be vindicated.”

So too does the author prefer Gould’s accent on the caprice of mass extinctions along with its implied, attendant claim that such calamities are qualitatively distinct from run-of-the-mill background extinctions.  Recently, some have suggested that certain so-called mass events had actually resulted from routine climate change, competition, or merely localized bad luck.  Much debate in particular has centered on the Cretaceous/Tertiary boundary 65 million years ago.  Skeptics of the meteor impact’s significance wonder why crocodiles, turtles, and frogs survived while dinosaurs (excepting birds), pterosaurs, pliosaurs, and other marine reptiles did not, arguing that some such creatures had dwindled or even gone extinct prior to the impact.

Ever the committed fossil hunter, however, Gould highlighted the 570 million year old remains of the frond- and disc-shaped Ediacaran fauna (perhaps more akin to lichens than animals, according to others), their abrupt disappearance following the start of the Cambrian Period 543 million years ago, and the ensuing “explosion” of fossil evidence documenting the emergence of today’s major lineages.  Similarly, Sterelny underscores the catastrophe that devastated 90 percent of animal species at the close of the Permian Period 251 million years ago.  Again, although he certainly acknowledges the fact of mass extinction, Dawkins has demoted these events to simple interruptions in the omnipresent process of selection.  For Gould, by contrast, such chance calamities were paramount, dealing the death card to some groups and a royal flush to others.

But the most incisive fissure between these two men opened over the relentlessly messy subject of human behavior.  Gould savagely opposed sociobiology and, perhaps to a lesser extent, its descendant, evolutionary psychology, insofar as they presumed selective underpinnings.  On the one hand, Randy Thornhill’s hypothesis that, under certain circumstances, sexually isolated men can improve their reproductive fitness through rape is easily criticized for its failure to consider, among other things, the obvious social costs of violence.  On the other hand, Gould found adaptive theories of differential parental investment more promising.  Some emotional propensities common to men and women, he suggested, might well be adaptive, given that males find advantage in spreading their sperm as widely as possible and that females are most successful when able to extract additional time, investment, and attention from males.  Even so, Gould warned, the range of behaviors that can be explained in such Darwinian terms was severely limited.

Although Dawkins employed certain tools distinct from those standard to most sociobiologists and evolutionary psychologists—the meme in particular—he has remained steadfast in his commitment to the evolutionary paradigm as the optimal strategy for understanding human behavior—an important observation that inevitably leads us to a more heady and comprehensive evaluation of this classic intellectual clash.  In some ways, Gould seemed to fear what he imagined to be science’s potentially injurious stabs into the soft, sensitive underbelly of human existence.  Dawkins, by contrast, seems to fear almost nothing.  Indeed, he manages to maintain a contagious optimism over the tender topics of sociality and morality precisely because he recognizes, first, that science is far and away the best if not the only honest and practical method of discovering truth, and, second, that the more fortunate realities of our evolved behavior—specifically the fact of cooperation—are both liberating and hopeful.  In the end, Sterelny agrees more with Dawkins, and, despite a deep and humbling appreciating of Gould’s extraordinary talents and accomplishments, so do I.  Had I not felt much as Dawkins apparently does, after all, I probably wouldn’t have bothered to write this article.

Book Review: Michael Shermer, Why Darwin Matters: The Case Against Intelligent Design (Times Books 2006). 201 pp.

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well.  He may be contacted at krausekc@msn.com.

Is evolution a fact of natural history?  Evidently.  Is intelligent design theory an incredible yet shrewd evangelical device valuable primarily if not only to monotheists?  Of course.  Interested and scrupulous persons have known as much for decades.  Why, then, do religionists and empirico-rationalists continue to battle over the issue?  Can either side prevail, and, if so, how?

Typically renowned as an uncompromising skeptic, Michael Shermer obviously believes that the conflict can be won, though, to my knowledge, he has never demonstrated adequate grounds for that conviction.  Perhaps more controversially, however, in Why Darwin Matters, Shermer implies that victory will spring from the eager assistance, if not candidly informed consent, of monotheists themselves.

On the one hand, the author proudly touts popular debate and education, evidently presuming the overwhelming power of untainted truth to change minds, which, to this point, have shown no dedication to such values.  Shermer carves the human turkey into three portions of unspecified dimensions.  “Fence Sitters,” he vies, comprise the succulent spoils for competing creationists and skeptics.  Having only “heard something” about the dispute, Fence Sitters actively “wonder what the explanation for it might be.”  Apparently, Fence Sitters can either resist humanity’s innate vulnerability to cultural corruption or prosper in an inaccessible hideaway beyond the reach of all print and electronic media.  In either case, these heroically disciplined or astoundingly deprived Fence Sitters will no doubt find inspiration in Shermer’s latest book—assuming, of course, that one of their order somehow manages to locate a copy and smuggle it past the guards and back into her cloud city, magical forest, or underground lair.

Consistent with all of the author’s full-length work, Why Darwin Matters is engaging throughout.  Most relevant to its subtitle, however, is the book’s longest chapter, “Debating Intelligent Design,” wherein Shermer presents and briefly refutes what he considers to be the opposition’s “ten most cogent—and most commonly presented—arguments.”

The discussion pertaining to the allegedly irreducible complexity of certain living systems is perhaps the most relatable.  According to prominent creationists like Michael Behe, evolution cannot account for the adaptive functionality of certain complex structures—human eyes, bird wings, and bacterial flagella, in particular—at every stage of their development.  Not so, Shermer answers.  The eye began as a mere collection of light-sensitive cells that eventually recessed into the organism’s skin, furnishing the organism with a more accurate means of distinguishing a light source’s direction.  At some point, a pin-hole camera eye materialized, eventually giving way to a lens eye.

The gradual development of propulsion devices like wings and flagella, by contrast, can be explained by exaptation, the process by which “a feature that originally evolved for one purpose is coopted for a different purpose.”  Both feathers and flightless wings might have developed originally for the purpose of thermoregulation rather than flight.  Similarly, bacterial flagella might have evolved from structures that were used for adhesion or secretion rather than propulsion.

On the other hand, Shermer appears to sacrifice frank discussion and education to fear and cynical politics.  Evolution, he warns, “is not under debate; it is under attack” in a “religious war against all science.”  And he might be right, given the character and temperament of his antagonists’ recent sermons.  Mathematician William Dembski has urged his cohorts to employ intelligent design “to clear obstacles that prevent people from coming to . . . Christ.”  Phillip Johnson, a law professor, envisions hordes of belligerent creationists marching “into enemy territory, their very center, [to] blow up the ammunition dump.”  Reverend Sun Myung Moon has convinced author Jonathan Wells to devote his entire life to destroying Darwinism.  Shermer is surely justified as well in identifying right-wing religious groups as the most prolific financiers of the Wedge movement’s “hammer,” or the absurdly named and ravenously litigious Discovery Institute.

So what response to this attack, this devilish Christian ruse?  Should readers expect anything other than an equal and opposite reaction?  Rather than limiting himself to yet another straightforward yet ineffectual argument on the facts, though such argument is included if not featured, Shermer passionately assumes the offensive.  Christian readers, the author’s apparent target audience, should expect to feel patronized, condescended to and, finally, intimidated upon careful evaluations of the text.

Initially, the author urges religionists to “embrace science, especially evolutionary theory, for what it has done to reveal the magnificence of the divinity.”  That Christian readers know Shermer as an atheist of one kind or another, is inconsequential.  That Shermer attempts to redefine the reader’s god into a foundationless, featureless, new-aged abstraction that purportedly stands for nothing and everything at the same time—supposedly whatever the reader needs, so long as she renounces science and politics—is more significant.  Theists should not care when or how their god created life, Shermer instructs.  Only scientists should ponder such questions because god does not really “exist” in any intelligible way; god is “being itself, not a being.”

Quoting favored theologians, former president and Christian evangelist Jimmy Carter, and, twice, Pope John Paul II, Shermer at times seems obsessed with the maintenance of a pleasantly innocuous Christianity.  Even Charles Darwin, the author emphasizes, never thought of himself as an atheist, and, for whatever reasons, declined to criticize or even discuss supernaturalism.  At that, readers are asked to choose one of three familiar attitudes toward the relationship between science and religion: the Conflicting Worlds, Same World, and Separate Worlds models.  For himself, Shermer has privately chosen the first attitude, the “warfare” approach where “religion [is] always a potential threat to science.”  Christian readers, however, are quite predictably directed to select the ever peace-loving and submissive option number three.

Thus, each party is allowed to have its cake and devour it too.  Scientists may test and debate reality amongst themselves, undistracted by the mental meanderings of common slobs.  Religionists may enjoy vague and occasional comfort in their “spiritual fitness” as they shuffle their children off to public schools where they will learn to dutifully add, subtract and memorize the Krebs cycle, but never confront issues the potential solution to which might improve if not preserve innumerable future lives.

But if religionists refuse to accept a watered-down deity and to leave well-enough alone, Shermer warns, they will suffer dearly.  Religion and science can be reconciled only through confession to “different realities,” because “if you push the science to its logical conclusion, you will end up naturalizing the deity.”  And nothing, of course, can be both natural and supernatural at once.  Christians must swear to the existence of a rigid yet unproven boundary between religion and science “or else, as the book of Proverbs (11:29) warned: ‘He that troubleth his own house shall inherit the wind.’”  So, why does Darwin really matter?  Because, at the individual level, religion matters too much to risk.

Less erudite and stylistic than Dawkins, less technical and apolitical than Shanks, Michael Shermer’s latest text on evolution is both considerable as an educational endeavor and, as usual, entertaining to the point of betraying the author’s unique intellectual playfulness—a more Pigliucci-like contribution to the reasonably intelligent layperson’s continuing science education.  Notwithstanding its dubious premise, hideous dust-jacket, and arguably mischievous aim, Why Darwin Matters will prove a worthwhile experience for truly curious and, thus far, open-minded generalists, if such creatures really exist.

Book Review: Cameron M. Smith and Charles Sullivan, The Top Ten Myths About Evolution (NY: Prometheus Books 2007) 200 pp.

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well.  He may be contacted at krausekc@msn.com.

True, nearly 150 years following Darwin’s initial publication of On the Origin of Species, about half of Americans still believe that humans and dinosaurs coexisted at some point in natural history.  About half deny that people evolved from earlier species.  And, true, if one mentions the evolution of species outside of a laboratory or classroom, then one should also expect an unfortunate response something along the line of, “I don’t believe it!  After all, I’ve never seen half a cat!”

So why should we care?  Why not let people believe what they will?  Because it’s simply too late for that, answer educators Cameron Smith and Charles Sullivan.  Socially, intellectually, scientifically, and technologically, we’ve come entirely too far to reverse course.  Evolution is as critical to biology as electricity is to a pop-up toaster, and every citizen’s basic comprehension of biology is prerequisite to her ability to effectively confront crucial and now unavoidable issues like disease prevention, environmental protection, the safety of endangered species, stem cell research, genetic engineering, etc., ad infinitum.

So how to begin?  Perhaps with The Top Ten Myths About Evolution, suggest Smith and Sullivan, whose new text certainly looks and, upon first glance, feels like yet another in a recently long line of politically motivated and simplistic overviews of evolutionary history and science.  Then again, Top Ten Myths has been impressively researched, thoughtfully documented, and generally well written.  Although each chapter has at least something important to say, or to repeat, as the case may be, more informed readers might find the observations and insights tucked away in the generous endnotes more stimulating.  On the whole, then, Smith and Sullivan have managed to tender something challenging for some and valuable for all.

For instance, following a critique of the “myth” that evolution is “just a theory,” the authors relate not only the bare distinction between Darwin’s original theory and neo-Darwinism (or the modern synthesis), but also the somewhat more obscure facts surrounding Darwin’s pangenesis hypothesis.  Oblivious to the genetic basis of natural selection, Darwin seriously considered the possibility that traits acquired during an organism’s lifetime could be passed along to its offspring.  Tiny particles called gemmules, he speculated, would penetrate an organism’s sex organs, adding to its cache of reproductive information.  If nothing else, this brief discussion highlights the provisional nature and thus unparalleled dynamism of all science.

More predictably, Top Ten Myths delivers a polemic that, although factually appropriate, often borders on the needlessly apologetic and, in the end, the intellectually disingenuous.  Throughout the text, the authors defend evolution by one means or another against the teleological “Great Chain of Being,” the Scala Natura, or its persistent remains, apparently presuming a religious but theologically manipulable audience.

The medieval Great Chain classified all things hierarchically, from the strictly material (rocks, for example) to the purely spiritual (angels, archangels, and, of course, God).  All living things were fixed according to the seamless plan of a perfect creator.  The scheme infested more than religion, however, influencing Lamarck’s conclusion as well that species eventually progressed up the Chain as a result of each member’s lifetime achievement.  Smith and Sullivan effectively rebut the mistake of progress by noting that bacteria, rats, and cockroaches are, and will likely always be, among the most successful species on earth, and by reminding us that some organisms, internal parasites and cave-dwelling fish included, have actually grown less complex over time.  Similarly, the authors call attention to the metaphysical inconsistency of inferring an evolutionary purpose from a planet that has experienced at least five mass extinctions in the last 440 million years.

Because the Chain implied permanently distinct and easily identifiable species, its legacy frequently seduces modern religionists into an exaggeration of the fossil record’s “missing links,” or alleged want of transitional forms.  Such gaps, of course, can be explained in a number of ways.  No doubt every naturally abrasive force from tectonic shift and volcanism to simple erosion can be blamed to some extent.  But not every organism can fossilize, especially those with soft bodies.  And those that can fossilize must surrender themselves at the right time under opportune circumstances in order to do so.  Bones, teeth, and shells will suffice, assuming a sedimentary environment, but even they will most often fragment, crumble, and deteriorate long before they can fossilize.

As for the “half a cat” quandary, species classification is not, and perhaps will never be, a visually or conceptually satisfying, less said an exact, science.  Although speciation is considered a function of reproductive isolation, as the authors point out, lions and tigers, for example, can mate and, at least in captivity, produce baby “ligers” or “tigons,” whichever you prefer.  Genetically, they are considered one species but, behaviorally, lions and tigers are diverse enough to merit separate classification.  Regardless, kitties become kitties very slowly, over greater spans of time than human brains have evolved to contemplate, much less comprehend in any meaningful way.  And although cats are always changing, their genes forever drifting and adapting, it is certainly true that one will never witness a creature that is half cat and half something else.  So be it.

But so-called “missing links” have been found, between fish and amphibians, amphibians and reptiles, and reptiles and mammals.  The remains of archaeopteryx, for example, revealed a crow-sized creature sporting both bird and lizard-like features.  We have located as well the fossils of warm-blooded reptiles called therapsids, and of many transitional species leading from Eohippus to the modern horse.  And time and again we have unearthed the fossils of our own ancestors which are neither Homo (of the human genus) nor Pan (of the chimpanzee genus), but rather Australopithecus (meaning southern ape): large, bipedal African hominids with relatively small brains, the earliest members of which lived four to six million years ago, when they diverged from forest-dwelling chimp and gorilla-like primates.  These creatures separated into two groups: the robusts, which died out about one million years ago, and the graciles, which might have been our ancestors.  Lucy, in fact, was a 3.2 million year old australopithecine discovered in Ethiopia in 1974.

The Great Chain, of course, has most recently culminated in the unfortunate doctrines of creationism and its thinly veiled cousin, Intelligent Design.  Smith and Sullivan devote a chapter to each, adequately exposing them for what they really are—blunt but effective tools of religious desperation.  In the process, however, the authors draw an unhelpful distinction between philosophical and methodological naturalism, the former rejecting anything that purportedly cannot be explained by natural laws and the latter withholding all possible judgment in that regard.  In the end, they observe, science has nothing to say about gods and souls so long as we assume such things are not part of the physical world.  And belief in God (yes, “God” with a capital, monotheistic, Abrahamic “G”), the authors vie, “is not incompatible with evolution or science in general.”

Belief without evidence—in fact, belief impervious to all evidence—is not incompatible with science?  Such is either the mother of all politically convenient cop-outs or unmistakable confirmation that the Great Chain’s influence persists, at least with respect to its preposterously naive segregation of humanity and its God.  Moreover, we simply cannot assume, as much as we might like to, that God and his alleged carryings-on are not part of the physical world.  To the contrary, the Abrahamic texts make it painfully, brutally, agonizingly clear that God has supposedly had a great deal to do with us and our planet.  As Smith and Sullivan had at least begun to say, we simply can’t afford to continue to offer these kinds of compromises.

Book Review: Steven Rose, ed., The Richness of Life: The Essential Stephen Jay Gould (Norton 2007). 653 pp.

by Kenneth W. Krause.

Kenneth W. Krause is a contributing editor and “Science Watch” columnist for the Skeptical Inquirer.  Formerly a contributing editor and books columnist for the Humanist, Kenneth contributes regularly to Skeptic as well.  He may be contacted at krausekc@msn.com.

If the course of evolution were commanded by a superior intelligence or according to some species-centered notion of progress, humans might reasonably expect to be surrounded by the likes of Stephen Jay Gould.  Before his regrettable death in 2002, Gould was a prolific and award-winning author, a distinguished member of the National Academy of Sciences, and Harvard professor of zoology and geology for more than thirty years.  But informed laypersons know better than to take such brilliance for granted, thanks in large measure to Gould himself.

After three billion years of unicellular ascendancy, then a mere five million years of Cambrian creativity, the last 500 million years of “variation on set anatomical themes,” Gould argued, “can scarcely be read as a predictable, inexorable, or continuous trend toward progress or increasing complexity.”  Natural selection, in fact, has never favored sophistication.  Rugged, diverse, and highly adaptable, bacteria (and archaea) are, have long been, and will likely always be the most successful life form on Earth.  And what could be more random—more lucky or unlucky depending on your perspective—than death by mass extinction?

Consider the fates of the diatoms and small, rat-sized mammals that lived 65 million years ago, just before the inauspicious asteroid impact off the Yucatan peninsula.  Diatoms didn’t survive because they were loved from above or because of their advanced biology.  These single-celled players hit the Cretaceous jackpot only because they had previously evolved a seasonal dormancy strategy.  Nor were tiny mammals in any way superior to the dinosaurs with which they had coexisted for 100 million years.  Only their diminutive stature allowed them to persist and us to subsequently evolve.  Complexity, intelligence, and even consciousness, in other words, were begat by nothing more progressive or divine than dumb luck.

But Gould was celebrated as well for his gritty confrontations with fellow intellectuals, zoologist Richard Dawkins and philosopher Daniel Dennett, most conspicuously, each of whom he pejoratively referred to as a “Darwinian fundamentalist” or “ultra-Darwinist” because of their alleged insistence upon interpreting every organismal attribute as an adaptation for reproductive success.  Their “adaptionist program,” as Gould referred to it, dogmatically assumed natural selection to the erroneous exclusion of all other evolutionary mechanisms.

With Dawkins, Gould took issue on two fronts.  First, the idea that organisms amounted to little more than passive vessels puppeted by genes struggling for reproductive advantage represented, in his estimation, the pinnacle of adaptionism.  The “selfish gene” theory, Gould scolded, was “a logically flawed and basically foolish caricature of Darwin’s genuinely radical intent.”  Selection acts most prolifically upon organisms rather than upon individual genes, he responded, because significant phenotype modifications are produced only through complex inter-tissue genetic alliances along with environmental factors.

Second, and perhaps more thoughtfully, Gould rejected the claim that “memes,” or professed cultural units consisting of thoughts and behaviors, could evolve at all in Darwinian terms.  Biological forms, after all, are drastically more confined than cultures.  A platypus, for example, cannot incorporate rat genes to generate a “ratty-pus” lineage because evolution can operate only on preexisting raw materials.  Ideas and behaviors, however, can diverge in an essentially Lamarckian mode, borrowing from or incorporating potentially infinite others at any time.  Religions, for instance, have frequently interconnected with, hijacked, or simply sponged from independent creeds to form mythological hybrids (if only, as with Christian churches, to deny it later).  As such, Gould chided, “cultural change will receive only limited (and metaphorical) illumination from Darwinism.”

The author’s criticisms of Dennett stemmed, for the most part, from the latter’s 1995 attacks against Gould’s pluralist convictions.  Dennett, apparently, had denied the dominance of “punctuated equilibrium” (a theory introduced by Gould and Niles Eldredge in 1972 proposing that evolution proceeds in extended periods of relative stasis punctuated by brief intervals of rapid change) over “gradualism” (the traditional Darwinian expectation that significant and directional modification occurs very slowly through geological time) in the creation of new species.  But only the theory of punctuated equilibrium, Gould argued, could predict exactly what we have found (and not found) in the fossil record—evidence of overwhelming changelessness and sudden morphological macroevolution among small and geographically peripheral populations. Gradualism alone, he concluded, simply cannot account for the archeological facts.

So too had Dennett maligned the importance of “spandrels,” structural yet non-adaptive by-products of evolutionary change as fodder for later adaptive reuse, or exaptation.  Because organisms are profusely complex and integrated creatures, Gould explained, adaptive change always casts off material side consequences akin to architectural spandrels, or the roughly triangular spaces left over between a rounded arch and its surrounding rectangular frame and ceiling.  Consider reading and writing, for example.  Each must have originated as a non-adaptive spandrel, since the human brain achieved its present size and structure tens of thousands of years prior to literacy.  “Taken together,” Gould surmised, “punctuated equilibrium and spandrels invoke the operation of several important principles in addition (and sometimes opposed) to conventional natural selection.”

Arguably, the author was considerably more patient with religious dogmatism.  Gould’s now well-worn doctrine of discreet teaching authorities, or “non-overlapping magisteria,” proposed that, because science probes only the empirical realm and religion only moral and spiritual issues, the two should never contradict, less said come to blows with one another.  Indeed, Gould offered Pope John Paul II’s 1996 recognition of evolution as confirmation that there can and should exist a “respectful, even loving, concordant between science and religion,” as if the European Church could possibly have continued to deny the unassailable evidence without sacrificing all of its remaining credibility.  Regardless, religious dogmatism represents at best only a single stage in the course of moral evolution, and a now-antiquated one at that.  History, after all, has abundantly demonstrated the ethical superiority of an empathic, empirico-rational methodology and worldview.

Even so, Gould never shrank from creationist challenges, no matter how misguided or obnoxious.  Nor did he take them personally.  A consummate scientist, Gould simply seized upon these challenges as opportunities to educate the educable, if not the creationists themselves.  Prior to 1994, for example—and still today, no doubt, among ever-inveterate and proudly uninformed young-Earthers—religious demagogues regularly mocked Darwin’s generally prescient suggestion that whales evolved from bear-like land mammals.  A few such detractors even managed to ask the helpful and appropriate question—Where are the transitional fossils?—to which Gould and others politely and decisively responded as the evidence became available.

In 1983, Phil Gingerich and colleagues unearthed the skull of Pakicetus from Middle Eocene sediments some 52 million years old in modern-day Pakistan.  Although considered the oldest whale, Pakicetus retained certain features in its teeth and auditory structures that appeared to identify it as an ancestor of the mesonychids, carnivorous runners that fed upon fish at rivers’ edges (others suggest that whales are more closely related to artiodactyls).  Seven years later, Gingerich found hundreds of partial skeletons including a complete hind limb belonging to Basilosaurus isis, an ancient whale that inhabited Egypt five or ten million years after Pakicetus.  Judging by their diminutive leg size, however, these creatures had already made the transition from land to sea.  Thus, although an important discovery, Basilosaurus could not serve as a true intermediate.  In 1993, though, the hind limbs of Indocetus ramani, another early whale that lived between the eras of Pakicetus and Basilosaurus, were located in India and Pakistan.  Clearly amphibious, Indocetus could still support itself on the firmament to which it likely returned to birth and raise its offspring.

Gould’s “smoking gun”, however, arrived in 1994.  Slightly younger than Pakicetus, Ambulocetus natans revealed a truly intermediary method of locomotion.  Its feet and hind legs were large and robust and each of its toes culminated in a tiny hoof, much as those of its suspected mesonychid ancestors did.  Its forelimbs, by contrast, were much smaller and may have served primarily for stability—as with modern sea lions.  But the shape of its lumbar vertebrae enabled Ambulocetus to swim in a characteristically cetacean-like manner—by dorsoventral (back-to-belly, as opposed to side-to-side like a fish) undulation.  Such motion, Gould noted, is also common among today’s fast and agile carnivores, and was probably so among their ancient counterparts.  Last, but not least, Gingerich and company published their description of Rodhecetus karsani, another specimen from Pakistan and perhaps the oldest deep-water whale.  Just a few million years younger than Ambulocetus, but substantially older than later whales fully committed to the sea, Rodhecetus bore a shorter hind limb and, like modern whales, unfused sacral vertebrae.

Together these and other fossils display an unmistakable diversity among ancient whales.  For Gould, who gushed freely over every satisfying detail, they represented as well the triumph of popular but genuine science over obstinate creationist ideology.  No doubt, we’ll miss his enthusiasm no less than his expertise.

As the title implies, The Richness of Life is both varied and penetrating.  At one point, Gould stretches well beyond the lay reader’s intellectual grasp.  But better his unrivaled acumen should occasionally leave us dry than his communitarian passion ever condescend to our weakness for wanton simplicity.  Science has never dispatched a more fluid or informed writer, or one with a deeper sense of social responsibility.  Who better than Gould, then, to relay the most exquisite, dreadful—and the most relevant—drama of all time?