This entry is part of a series. For a bit of an introduction and an index of all entries in the series, go here.

This installment covers Chapter 18, The Mason Bee.

There's nothing in particular about the following passage - I just thought this was funny.

The clash between monophyletic evolution on the one hand, with its rejection of God, and polyphyletic variation on the other with its fixed laws, plan and purpose, merely serves to emphasize the vagueness and uncertainty of the materialist's extravagant speculations and to show the loss of an objective worthy of the pursuit of rational man. (McCann 222)

First I have to deal with people saying bees show my own field of aerodynamics is impossible. Now, I see McCann saying that it also shows that evolution is impossible.

The materialist encounters in the bee an insurmountable obstacle which would be no obstacle at all if the Creator were not rejected. (McCann 222)

Monophyletic evolution demands acceptance of the theory that the bee was evolved from a lower organism which neither made honey nor built a hive, notwithstanding the fact that the one distinguishing characteristic of the bee is that it is the only creature in nature that does both, though no explanation of its instinct as a honey gatherer and hive builder has ever been offered. (McCann 223)

Hmm. Wasps couldn't be seen as any type of analog as a precursor to bees, huh? As a kind of communal insect that makes hives but not honey?

This one doesn't exactly have to do with evolution, but it is pretty insulting to the non-human animals he's describing.

Much has been written about the "singular intelligence" of the bee. It has been compared to human reason just as the intelligence of dogs, seals, and other animals has been compared to human reason, as if upon the brains of some of them, learning their tricks, the human intelligence of the teacher had not been imposed. (McCann 225)

I've never understood how a person could have pets, and not recognize the personality and intelligence of those creatures.

McCann posed the following strange argument from instinct.

Who forms the plan of the bee? (McCann 226)

Yet even the untrained observer detects the strained quality of these theories of chance evolution. He notes that acquired habits vary, but that instinct never varies. (McCann 226)

The plan of the bee, obviously, comes from instinct. No higher intelligence plans it. But where he goes off the rails is in saying that instinct never varies. Why not? Instinct is just one more trait controlled by our genes. If physical traits can vary with genetic mutation, why wouldn't instinct, also?

McCann seems to think the chicken and the egg is a serious problem for evolution.

If the specific law is that each species comes from the germ of its own species, every bee since the first has been hatched from the egg of a pre-existing bee. Whence came the first pre-existing bee? Like begets like. We get no bee, except from the egg of another bee. (McCann 227)

This is the very question that evolution explains. Every parent begets offspring very similar to, but not exactly like, themselves. The changes from generation to generation may be very small, but these changes can add up to a lot over time. Think back to my example from a previous installment of short necked animals evolving into long necked animals, where the average neck length of the population only changed 1 mm per generation. From generation to generation, nobody would notice any big differences between parents and offspring. But after a thousand generations, the population would look quite a bit different than their many times great grandparents.

If you were to somehow travel in a time machine, tracing the ancestry of a given bee hive, you wouldn't notice any big changes from generation to generation. But, you would notice that the ancestors become icreasingly different from the modern day hive. Initially, they would still be bees, just slightly different. Then, they would still be bee-like, but not quite bees. Keep going further and further back, and you'd find insects that weren't bee-like at all, and even further into the past, it would be a worm-like population of animals. You could keep tracking the ancestors until eventually you got back to the first life on the planet, never noticing a big change from one generation to the next.

Modern creationists would be very familiar with the following argument, only now they've given it the term 'irreducible complexity'.

The chance evolutionist suggests a low form of pre-existing honey-gatherers and a low form of pre-existing cell-makers as the ancestors of the bee. But if this be true, the first product of the chance evolution must have been equipped with an apparatus for gathering honey and a plan for making cells. The bee couldn't have acquired this apparatus SLOWLY. It couldn't have developed its tools and its skill SLOWLY for the reason that its offspring could have survived no such delay. (McCann 228)

I don't know much about bee evolution, to be honest, but seeing as how many types of animals make nests/dens to raise their young (birds, ants, wasps, mammals), and many types animals produce a nourishing food for their young (some birds, mammals, honey pot ants), I don't see why the two would have had to have evolved together in bees. Perhaps the ancestors of bees simply made the cells to protect their young, and then co-opted that already existing structure to store honey. Cells and honey would each have been useful independent of the other.

Here's the same 'irreducible complexity' argument concerning mammals.

How could the new-born infant of a mother who had not yet developed mammary glands survive the delay of ages until chance evolution might succeed in developing mammals capable of suckling their young! ... But Darwin himself also says that the mammals have descended from the marsupials, and instantly we have a new set of complications in which the opossum, the kangaroo and the turkey become the most bewildering riddles of the chance evolutionist's scheme. Since Darwin's time no evolutionist has attempted to explain how, by chance evolution, the offspring could have survived the millions of years which are said to separate the marsupial from the mammal while the latter was evolving from the former, or, in other words, until the mammary glands of the mother could be developed beyond the pouch stage. (McCann 228-229)

Nobody except naive creationists expects that prior to the development of mammary glands, that our ancient ancestors gave birth to completely helpless young that would have starved to death. I think it's much more likely that nurturing behavior would have evolved first (such as in birds), and then later, mammary glands would have developed initially as a supplementary food source for the young. And then only much later than that would mammary glands provide the primary food source for infants.

Speaking of mammary glands, I think the platypus and the echidna are a very good example of what 'primitive' mammary glands would have been like in our ancestors. They produce milk, and excrete that over a region of their body, but they don't have ducts to transport the milk, nor nipples where the babies can latch on to suckle.

This line of reasoning is actually a bit funny.

All theories of chance evolution repudiate plan, purpose and definite intention, yet the sting of the bee is certainly an organ of definite intention. (McCann 229)

Because having to commit suicide to defend your colony shows clear intent in design. It's even worse when you consider other animals have evolved stingers that don't leave them dead after using them.

I really, really wish McCann could see the fossils coming from Liaoning.

On the theory that special organs, designed for a particular use, were developed ever so slowly before the time came when they might be used, it would be necessary for birds, evolving from reptiles, to acquire feathers gradually through thousands and thousands of generations before such feathers could be used for flight, and, of course, during all this period of development there would have had to be another and equally marvelous co-ordination of development in the direction of flying bones and flying muscles, and a still more marvelous co-ordination, all by chance, whereby the center of gravity of the bird would fall within the limits of flight. (McCann 229)

This is exactly what has happened. Feathers originally evolved in dinosaurs, having nothing to do with flight. Flight like feathers might have evolved originally for display purposes, or maybe even for extra thrust to aid the dinosaurs while running. Later, these already developed flight like feathers would have been used for actual flight (either short powered flights or gliding). And considering that an animal can move its limbs to adjust its center of lift, it wouldn't have been hard for the CG and center of lift to be in the correct locations relative to each other. Once rudimentary flight had been developed, then natural selection would have favored modern asymmetrical flight feathers.

More info:

• More info on Liaoning Fossils
• Book Review - Archaeopteryx: The Icon of Evolution

Proceed to Chapter 19

Posted by Jeff on Friday, Jun 10 | Permalink | Comments (32) | TrackBacks (0)

This entry is part of a series. For a bit of an introduction and an index of all entries in the series, go here.

This installment covers Chapter 17, Psychical Activity.

Here we see what might be a precursor of the now common entropy argument.

Natural science compels us to assume certain formal principles, which are not makeshifts meddling with material energy, nor do they disturb the permanence of the law of energy; they simply direct the lower energy, quicken to life the atoms hitherto dead by absorbing them into the organism and, in short, effect THE PURPOSE of the vital processes by action from within. This postulate is eminently reasonable - I personally cannot dispense with it, and should not be able to dispense with it, even if theology did not exist. (McCann 214)

There's all the talk of energy that creationists now like to bring up when discussing the Second Law of Thermodynamics, but this could just be vitalism. Now I wonder if vitalism somehow influenced the Second Law canard, or if it's just a matter of trying to sound 'sciencey' by talking about energy.

Then we get the 'evolution says we're nothing but chemicals' complaint.

But, according to the latest theories of the materialistic evolutionist, as announced at the Second International Congress of Eugenics, American Museum of Natural History, New York City, September, 1921, it is not the soul that distinguishes man from the ape, but rather a physical difference brought about by the action of the endocrine glands, the secretions of which are responsible for the development of man from the ape. Dr. Charles B. Davenport, director of the Eugenics Record Office, says that all crimes and all moods are produced by various chemicals called hormones, which are manufactured by the different glands and poured into the blood stream which carries them to the different organs, including the brain, where they produce profound bodily and mental effects. (McCann 216)

We now have the benefit of nearly a century's worth more research, and it's very clear that our brain chemistry affects our moods and actions. The most common example is alcohol, but there are also the new drugs used to treat depression, ADHD, and other aspects of personality.

In fact, the more we learn about the brain, the more superfluous souls become. Go read Ebon Musing's article, A Ghost in the Machine, for lots of good examples of how our material brain is sufficient to explain our personalities.

After mentioning a hypothesis that perhaps meat eating gave our ancestors the extra energy needed to develop larger brains, McCann again demonstrates the misconception of a ladder of progress.

Dogs, cats, wolves, hyenas, lions, tigers, vultures and other carnivorous creatures have been eating meat for thousands of years, and doubtless in time will more fully develop the distinctively human factors which even now, due to a meat diet, must be well advanced, though unobtrusively so, on their way to the human stage. (McCann 218)

We are a very rare animal. It took a very specific set of circumstances to come together to lead to our evolution. It wasn't simply eating meat that transformed our ancestors into humans. That was only one requirement (which gave us the calories for our big, energy intensive brains). With how much energy (i.e. food) big brains require, it takes a specific type of environment where the advantages offset the disadvantages (for us, it appears to have been for social reasons). But even just being smart isn't going to make a human. Look at dolphins and elephants. They're pretty damn smart, too.

From our modern perspective where humans dominate the planet, we don't realize how precarious our survival was in the past. There's some evidence that we nearly went extinct 70,000 years ago. There was a fair amount of luck in our lineage surviving, and but for a disease outbreak at just the wrong time, I might not be sitting at a computer writing this, and you wouldn't be reading it. In other words, there's nothing driving evolution to produce human like animals.

Here we get two misconceptions for the price of one - evolution can't produce new information, and evolution can't explain a subjective experience.

It would be difficult following William Bateson's dictum, "An organism cannot pass on to its offspring a factor which it did not itself receive in fertilization," to attribute the music faculty of man's soul to the seed of an ape...

The evolutionist who says there are no miracles is confounded by the miracle of music and made dumb by speculation concerning its origin. (McCann 219)

I'll cut McCann a tiny bit of slack in the first claim. Genetics wasn't as well understood then as it is now, so mutation wasn't understood. But now, of course we know that children can pass on genetic information that they didn't receive from the parents. I've already covered all this in previous entries in this series, but just to repeat, current estimates for human mutation rates are around 100 mutations per individual. And I'll once again link to information on Richard Lenski's experiment, where e. coli developed mutations that gave them the ability to digest a new food source (citrate), as an example of how random mutations can result in new functions. I'll also link to an article by Richard Dawkins, The Information Challenge, which explains the processes of how information can be added to the genome.

Proceed to Chapter 18

Posted by Jeff on Friday, Jun 3 | Permalink | Comments (0) | TrackBacks (0)

This entry is part of a series. For a bit of an introduction and an index of all entries in the series, go here.

This installment covers Chapter 16, Bateson - A Brilliant Light.

Knowing what we now know about genetics, it's hard to imagine a time when people would have thought that it cast doubt on evolution. Here, McCann was quoting one of the founders of genetics, William Bateson.

"If we cannot see how a fowl by its egg and its sperm gives rise to a chicken or how a sweet pea from its ovule or its pollen grain produces another sweet pea we at least can watch the system by which the differences between the various kinds of fowl or between the various kinds of sweet pea are distributed among the offspring. . . . Until Mendel began this analysis nothing but the vaguest answers to such a question had been attempted. THE EXISTENCE OF ANY ORDERLY SYSTEM OF DESCENT (denied by Haeckel) WAS NEVER EVEN SUSPECTED." (McCann 205-206)

It's a bit silly to say that "the existence of any orderly system of descent was never even suspected". Of course an orderly system was expected. It's pretty obvious that dogs don't give birth to cats. The difference is that before Mendel, most scientists suspected blending inheritance. Mendel discovered that whatever it was that controlled inheritance was discreet. We now know that it's our genes, coded in DNA.

Here's another case of human exceptionalism.

Alas, by what violence of imagination are we to trace man's inheritance of the art faculty, the metaphysical faculty, the faculty of wit and humor, the faculty of scientific investigation, to the seed of an ape or of any other lower animal, without the intervention of God? (McCann 206)

I'm not going to quote de Waal yet again, but here's a link to his article in the New York Times.

We're probably smarter than any other animals. We're certainly more technological, and are the only animals that practice science. But let's not get too conceited over it. If we were cheetahs, we'd scoff at how slow all the other animals were. Or if we were blue whales, at how small they were. Or if we were swifts, at how land-bound they were. For any given trait, some species is going to be the best. But it's just one trait. Plus, it may not be the best by much. Just like a pronghorn is nearly as fast as a cheetah, dolphins and elephants appear to be nearly as smart as us, just not with a technological bent. The other great apes are all pretty smart, too.

Although McCann sees humans as much, much higher than 'lower' animals, he still apparently doesn't have a very high regard for our species.

We are living in an age of intellectual pride which takes as little heed of its futile vanities as of its paradoxical pursuit of gross humiliations. Few of us stop to consider that it was not the brain of the average fallen man that has given us the printing press, the cotton gin, the smelter and the anvil, the engine and the dynamo, the telegraph and the telephone, the trans-Atlantic liner and the aeroplane, the microscope and the telescope. We employ these majestic discoveries as if they were our own; as if they had not been given to us by a comparatively few geniuses standing as solitary luminaries above and beyond the average mass of fallen humanity. The poet Longfellow must have had some such thought in mind when, referring to the Mother of Christ, he penned the line, "Our tainted nature's solitary boast." (McCann 208-209)

Maybe things were different in McCann's time, but it's certainly not the scientific community that conflates evolution and abiogenesis these days.

By this time the student through his examination of facts and contradictions has probably arrived at the conclusion that the whole doctrine of evolution has been directed into lanes of confusion and darkness by reason of its vain assumption that its object was to explain the origin of life upon this planet. To attain progress along this deliberately selected route it was forced to espouse the assumption of a monophyletic evolution of the whole kingdom of organic life from a single cell which sprang into existence through some never repeated phenomenon of spontaneous generation. (McCann 210-211)

In discussions such as this, though, the distinction between evolution and abiogenesis is a bit of a moot point - there are few people who accept evolution who wouldn't also accept abiogenesis. However, 'monophyletic evolution' was not an initial assumption. It was the conclusion after studying the evidence.

You can see the precursors of the creationist micro- vs. macro-evolution canard.

The net result of his [Standfuss - jrl] extraordinary experiments took the shape of an opinion that the only really important variations of species are those modifications caused by definite external influences, which modifications, described as "adaptive variations" are transmitted to succeeding generations. (McCann 212)

It is common nowadays to hear creationists say that 'microevolution' occurs, but not 'macroevolution'. These are in fact real terms, but they're misused by creationists. To quote from Talk Origin's Index to Creationist Claims, "Microevolution is defined as the change of allele frequencies (that is, genetic variation...) within a population... Macroevolution is defined as evolutionary change at the species level or higher, that is, the formation of new species, new genera, and so forth." Many creationists actually do accept that macroevolution as properly defined does happen (it's the only way to explain the Noah's Ark story), and instead take macroevolution to mean some unspecified big change. Still, where's the stop sign? If you have enough small changes over many generations, what's to stop that resulting in a big change? The journey of a thousand miles begins with a single step (and sometimes ends badly).

Despite all the talk of bad science, here McCann gets down to the real reason he doubts evolution.

Polyphyletic evolution, instead of getting back to an accident resulting in a single stock from which the myriads of modern living creatures in the animal and vegetable kingdoms have descended, begins with numerous stocks expressly created by God and controlled as to their variations by the operation of fixed laws revealing plan and purpose. (McCann 212)

It really is religion that makes McCann reject evolution.

Proceed to Chapter 17

Posted by Jeff on Friday, May 27 | Permalink | Comments (32) | TrackBacks (0)

This entry is part of a series. For a bit of an introduction and an index of all entries in the series, go here.

This installment covers Chapter 15, Chromosomes and Genes.

Darwin used artificial selection (breeding) as an analogy to natural selection. Here, McCann tried to cast doubt on that analogy.

Artificial selection selects exceptional, most widely divergent characters which appear only in a few individuals, whereas natural selection is a selection of slight differences appearing simultaneously in many individuals. Artificial selection often leads to morbid or exaggerated development, to a sickly disposition, to an undermining of the whole constitution, whereas natural selection effects no injury to the whole constitution but on the contrary strengthens and betters it. Artificial selection results in lack of stability. Natural selection remains constant.

"In the light of this truth," says Morgan ("Evolution and Adaptation," 1903) "the relation between the two selective theories may appear quite different from the interpretation that Darwin gives it." (McCann 195)

Artificial selection is still a very good analogy to natural selection. In fact, they're pretty much the same thing. It's just that the selection pressures can so heavily favor single traits in artificial selection, or become extremely relaxed for traits that domestic animals no longer need. For example, let's look at modern chickens. They're extremely exaggerated compared to wild chickens. They're little more than meat factories with the bare minimum of life support to grow that meat (more info). But selection explains exactly why they got that way. Farmers chose the most muscle bound chickens to breed, so they created the most offspring. Scrawnier chickens were sent straight to the slaughterhouse without a chance to make any baby chicks. Farmers have just become a new selection pressure compared to what wild chickens see.

I don't want to criticize McCann too much for misunderstanding genetics, since it was still a fairly young science in his time, but here is a perfect case of what the modern synthesis would bring to the theory of evolution.

Here the biometrician and the Mendelist part company. The biometrician says: "Selection is the process of accumulating infinitesimal differences through gigantic periods of time." The Mendelist says: "Selection is a process of combining and sorting out genes." The biometrician says: "Selection is creative, actually producing new characters." The Mendelist says: "Selection merely assorts, and such effects of variation as are sometimes said to be found are merely due to new combinations of characters that were already present." (McCann 196)

When McCann quotes an actual scientist immediately following the above paragraph, he can make a good point.

De Vries himself says ("Darwin and Modern Science," p. 70): "Natural selection acts as a sieve; it does not single out the best variations but it simply destroys the larger number of those which are from some cause or another, unfit for their present environment. In this way it keeps the strains up to the required standard, and in special circumstances may even improve them." (McCann 197)

We now know that both points of view presented above are right. Random mutation is the ultimate source of the genetic variation in a population, and mutation occurs all the time. Current estimates for human mutation rates are around 100 mutations per individual. Obviously, most of those are neutral, but some will be advantageous or deleterious, and even that will depend on environment.

So, thanks to mutation, you have populations of organisms with quite a bit of genetic diversity. Natural selection acts on that existing diversity - it doesn't create new characters. Go back to my hypothetical population from a previous entry, where an environmental change favors animals that can browse from the tops of trees. Natural selection never creates an individual with a longer neck. Random mutations create animals with longer and shorter necks than their parents, and natural selection describes how those animals with the longer necks survive and reproduce more. After many generations, the population will be composed of animals with much longer necks than the founding population, but it was random mutation that created the longer necks in each generation.

To anyone who's spent any time following creationism, the argument that genetic mutation can only cause the loss of information, and not create anything new, is a familiar argument. After reading McCann, I now realize that this argument is nearly as old as genetics itself.

But science is not looking for losses along the path of evolution. On the contrary science insists she is looking for gains, additions.

It is for this reason that so many scientists are reluctant to admit that characters which look like additions in domesticated or cultivated forms are really due to the LOSS of something which in the past has prevented the appearance of the hidden factor. (McCann 197-198)

I'll once again use Richard Lenski's experiment, where e. coli developed mutations that gave them the ability to digest a new food source (citrate), as an example of how random mutations can result in new functions. I'll also link to an article by Richard Dawkins, The Information Challenge, which explains the processes of how information can be added to the genome.

With the way so many people today use the term 'Darwinism' synonymously with evolution, it's interesting to see it used in a slightly different (and probably more accurate) context.

"Klebs, the eminent plant physiologist," says Kellogg, "keenly criticizes the mutation theory. Copeland finds in the mutations of De Vries nothing radically different either in character or behavior from the Darwinian fluctuating variations." (See "Darwinism Today," 1907, pp. 372-373). Having abandoned Darwin and come to De Vries, there would thus seem to be a desire to return to Darwin. On this point Kellogg is clear and emphatic. He says, under the caption, "The Deathbed of Darwinism," in the introduction to "Darwinism Today," 1907: "... Numerous books and papers are appearing now in such numbers and from such a variety of reputable sources as to reveal the existence among biologists and philosophers of a widespread belief in the marked weakening, at least, if not serious indisposition of Darwinism. A few of these books and papers from scientific sources even suggest that their writers see shadows of a deathbed. (McCann 199)

So, Darwinism here isn't simply evolution. It's contrasting Darwin's evolutionary theories with De Vries' evolutionary theories.

With how much we take for granted our knowledge of genetics today, it's interesting to see this.

The remarkable fact has now been established that every species of plant or animal has a fixed and characteristic number of chromosomes. In many of the lower animals the number of chromosomes to the cell has been determined positively. With respect to man the number is now thought to be twenty-four. Wieman (1917) asserts that the number in both negro and white spermatogonia is twenty-four, thereby agreeing with Duesberg's (1906) count. (McCann 199-200)

The vast majority of people have 24 chromosomes. However, the number's not exactly fixed. Mutations involving fusions are so common that they have their own name, Robertsonian Translocations. Those people only have 23 chromosomes, and they get along just fine, though their children carry a higher risk of Down Syndrome and other similar disorders.

If only McCann could have actually seen the research he was wondering about.

At this writing, 1921, no scientist may foretell what a contrasted examination of the chromosomes of the chimpanzee, gorilla, orang, gibbon and man will reveal, yet the old dogmatic certitude of the evolutionists, who have heeded none of the bewildering complexities involved in this study, persists, as if it were indeed a thing upon which the freakish Trinil Ape-Man, Piltdown Ape-Man and Neanderthal Ape-Man might look with profound contempt. (McCann 201)

There's a very good comment in Pharyngula, that I often link to in these discussions (I have a local copy on this site it's so good). It discusses the very thing McCann mentioned - "a contrasted examination of the chromosomes of the chimpanzee, gorilla, orang, gibbon and man". We're related. Chimpanzess and bonobos are the most closely related of the great apes, and are next most closely related to humans. Our DNA is more similar to a chimp or bonobo than is that of a gorilla or orangutan.

We do have a different number of chromosomes than the other great apes, but when you look at our chromosome 2, you find telomeres and centromeres exactly where you'd expect if two chromosomes had fused together in one of our ancestors. And when you compare our chromosome 2 side by side with chromosomes 2p and 2q from the other great apes, you see marked similarities.

There's no doubt that all of us great apes are related.

Proceed to Chapter 16

Posted by Jeff on Friday, May 20 | Permalink | Comments (30) | TrackBacks (0)

This entry is part of a series. For a bit of an introduction and an index of all entries in the series, go here.

This installment covers Chapter 14, Complications.

Yet again, McCann shows his misunderstanding in thinking of evolution as a ladder. First, he quotes a scientist discussing fossil whales and their teeth, and then goes on to give his interpretation.

Sir J. W. Dawson ("Chain of Life," p. 222), says: "The oldest of the whales are in their dentition more perfect than any of their successors, since their teeth are each implanted by two roots, and have serrated crowns, like those of the seals. The great Eocene whales of the South Atlantic which have these characters attained the length of seventy feet and are undoubtedly the first of the whales in rank as well as in time. This is, perhaps, one of the most difficult facts to explain on the theory of evolution."

They start you off back there with a little squirrel-like creature when the whale was a mammal seventy feet in length, more perfect according to the bewilderment of evolution than it is today, and they ask you to believe that the little squirrel-like creature was the father of the modern horse.

There were the Eocene Eohippus and the Eocene whale. The Eocene Eohippus they say has been coming up, up, up, under the irresistible and unyielding pressure of evolution and is now the horse. What, then, happened to that unyielding and irresistible pressure that it failed to carry along with it the Eocene whale which, instead of coming up, up, up, in comfortable accommodation to the indispensable requirements of evolution, has conducted itself, perhaps because it had flippers, with so much flippant indifference to the pre-opinions, pre-assumptions and prerequisites of those who would have had it reverse its procedure?

They start you off with something very small as the progenitor of the Eocene Eohippus, but the Eocene Eohippus and the Eocene whale had a common ancestor. Why, therefore, was the progenitor of the little squirrel-like creature lagging along the line of evolution while the whale was attaining a length of seventy feet? Everything went forward very nicely with the little Eocene squirrel-like creature, yet we see that something must have stopped altogether while its contemporary, the Eocene whale, was making such monstrous advance. But this is the very apex of paradox, for we see that the little Eocene squirrel-like creature didn't stop at all, but kept going right on, whereas the monstrous advance of its contemporary, the Eocene whale, is seen to be no advance of any kind whatsoever but in truth a sprag in the cogs of evolution.(McCann 181-183)

One of the most important factors contributing to natural selection is environment. It should be obvious that whales and horses evolved in very different environments, so that traits that would have been favored in one lineage may not have been beneficial in the other. But even among each lineage, the different groups within the lineage lived in different environments. Early horse ancestors were forest dwellers. There are many reasons why natural selection may have favored a small size in those populations, such as lower food requirements, ease in getting around through the trees or in the branches, or more places to hide from predators. Modern horses and zebras live on the plains, where large size is by itself a defense from predators, and also allows the animals to run faster.

Modern whales do have very different teeth than their ancestors. In the dolphins and toothed whales, the teeth are actually simpler than most mammal's teeth. They're simple conical teeth. But recall that whales are aquatic predators. They catch slippery fish and eat them whole. They don't need molars to grind up tough plant material. There's also the possibility that the regular sizing and spacing of the teeth allows them to be used as arrays, to help the whales with echolocation.

Then, of course, there are the baleen whales. They have no teeth at all, but it's because they've evolved a complex body part that allows them to filter feed better than plain teeth would have. And yes, scientists have found a transitional form that has both teeth and baleen (more info on baleen whale evolution).

This following paragraph is exactly what common descent means.

Its [a bat's] wings are like our own human hands. That is why they had to start the first horse with five toes. The evolutionist sees modifications of the same structure in the paws of cats and dogs, the hoofs of horse and cattle, the flippers of whales and porpoises, etc., yet the foot of the ape is scarcely so much a foot as a HAND! (McCann 183)

But this? Not so much.

In order, by the slowly acquired accumulation of infinitesimal differences in gigantic periods of time, to develop the primitive generalized fore-limb from which all these diverse forms evolved, the bat before acquiring a wing capable of flight would have had to have countless hosts of ancestors, millions of them, and man should be not a descendant of the ape so much as a cross between a tortoise and a lizard. (McCann 184)

Our ancient, ancient tetrapod ancestor had five toes on each foot, both front and back. Somehow this number became set in development (not that it's impossible to have a different number, but that the change is rather unlikely, particularly an increase). Subsequently, nearly all descendants of that ancient tetrapod ancestor have five toes on each foot. A bat wing is evolved from that ancient limb, as is our arm, a lizard's leg, a dinosaur's claw, or a horse's hoof. All of us subsequent descendants are cousins.

On some issues that McCann's brought up, I haven't been familiar enough with the state of science during his time to know whether science really was lacking in those areas. But on this one, there's no excuse.

But perhaps the bat is an exception among flying things? On the contrary, the same holds good of other flying creatures - birds, pterodactyles (flying lizards), etc. No trace of any of these creatures is found while their wings were in the making. (McCann 184)

Archaeopteryx was discovered in 1861. Surey, McCann should have heard of that, especially if he was doing any research for his book. At the very least, he could have brought it up to discount it, considering how many people have used it as an example of the very thing McCann is asking for.

Ah. A creationist screed just wouldn't be complete without conflating evolution with abiogenesis.

All this positive evidence, all this negative evidence, all this lack of evidence of any kind should demonstrate the folly of the theory that the whole organic world originated in one primitive cell under an accidental chemic urge that has never repeated itself. Moreover, it should show the folly of the theory that the animal and vegetable kingdoms emerged from the same ancestral cell. (McCann 187)

Abiogenesis is not the same thing as evolution. As I already wrote in a previous part of this series, the origin of life is as relevant to the study of evolution as the origin of the atmosphere is to the study of meteorology.

There is, however, a very good reason why we don't see new life springing up any more - advanced life is already here. When life was first getting started on this planet, it had no living competition. There were no hungry critters to gobble up organic molecules floating about, or to gobble up any incipient life. Now, bacteria are everywhere. There's practically no nook or cranny with the conditions where new life could get started that isn't already inhabited by bacteria.

After as much hoopla as there was over punctuated equilibrium when Gould pushed it, I thought it was interesting to read this.

Struck by the amazing lack of uniformity in what is called "the rate of evolution," its proponents must look to De Vries for help. De Vries believed there were periods of rapid change alternating with periods of fixed stability in the history of species. Consequently we find the idea of "periodic advances or waves of evolution." (McCann 188)

Keep in mind though, that De Vries was advocating saltationism, which was a bit different than punctuated equilibrium. When punctuated equilibrium advocates talk of "periods of rapid change alternating with periods of fixed stability", the 'rapid' is only in geologic terms. If you could somehow gather specimens from every generation during the 'rapid change' period, every generation would still look very much like the previous generation, with only slight differences. It's only the accumulation of many of those slight differences over many generations that results in a big change in the population. Saltationists, on the other hand, would predict that there would be a very noticeable difference from one generation to the next.

Saltation, as far as we can tell, doesn't happen. Even if, through the most unlikely of scenarios, a 'hopeful monster' were to be born, it would have no partner to mate with. Punctuated equilibrium, however, does appear to happen. The history of life on this planet seems to be a mix of punctuated equilibrium and gradualism.

I thought it was interesting to read this.

The significance of another admission of this modern Princeton professor [Conklin] is overwhelming. Announcing that one-celled organisms reached their utmost limits of complexity millions of years ago, he crosses the stream of life and reviews the higher animals and plants in all their multiplication of cells, tissues, organs, systems, metameres, and zooids which, he says, p. 20, "enormously increased the possibilities of specialization within each of these larger units of organization, BUT FOR MILLIONS OF YEARS THERE HAS BEEN LITTLE FURTHER PROGRESS IN THIS DIRECTION OF MULTIPLICITY AND COMPLEXITY." (McCann 188-189)

McCann's response shows the typical ego that many people have, considering humans to be separate from the rest of the animal kingdom.

Whence, then, came man with his extraordinary complexity of organization? (McCann 189)

First, I'll refute McCann's response, by simply quoting again something I'd already quoted in a previous part of this series, part of a recent article in the New York Times by primatologist Frans de Waal.

In the field of cognition, the march towards continuity between human and animal has been inexorable... True, humanity never runs out of claims of what sets it apart, but it is a rare uniqueness claim that holds up for over a decade. This is why we don't hear anymore that only humans make tools, imitate, think ahead, have culture, are self-aware, or adopt another's point of view.

If we consider our species without letting ourselves be blinded by the technical advances of the last few millennia, we see a creature of flesh and blood with a brain that, albeit three times larger than a chimpanzee's, doesn't contain any new parts. Even our vaunted prefrontal cortex turns out to be of typical size: recent neuron-counting techniques classify the human brain as a linearly scaled-up monkey brain. No one doubts the superiority of our intellect, but we have no basic wants or needs that are not also present in our close relatives. I interact on a daily basis with monkeys and apes, which just like us strive for power, enjoy sex, want security and affection, kill over territory, and value trust and cooperation. Yes, we use cell phones and fly airplanes, but our psychological make-up remains that of a social primate. Even the posturing and deal-making among the alpha males in Washington is nothing out of the ordinary.

Aside from having a big brain, humans are no more complex than any other mammal. (Actually, I always thought of birds as being more advanced than mammals in many ways, what with their feathers, air sac lung system, superior vision, etc.). In fact, when you get down to genetics, we're not even all that different from single celled eukaryotes or bacteria. All the functions that have to be carried out in our cells have to be carried out in those single celled organisms as well. Sure, we have organs and specialized tissues, but even bacteria can form colonies and have some degree of specialization. I'm not trying to say that we're not more complex than a bacterium. I think we are. I'm just pointing out that the difference isn't as big as some people would think. (On a related note, here's an entry on the evolution of complexity.)

McCann did make a good point that seems to be lost in the current popular notion of evolution, where so many people emphasize genetics in development, ignoring environment.

The composition of the soil determines largely the character of the plant's development, exerting a vast influence upon the variety of the species, the different individuals of which are influenced accordingly. (McCann 190)

In fact, I wrote about this in a previous entry of mine, Genetic Determinism. We're certainly the products of evolution, but we're also the products of our environment.

Proceed to Chapter 15

Posted by Jeff on Friday, May 13 | Permalink | Comments (30) | TrackBacks (0)