Skip to comments.Creationism: God's gift to the ignorant (Religion bashing alert)
Posted on 05/25/2005 3:41:22 AM PDT by billorites
Science feeds on mystery. As my colleague Matt Ridley has put it: Most scientists are bored by what they have already discovered. It is ignorance that drives them on. Science mines ignorance. Mystery that which we dont yet know; that which we dont yet understand is the mother lode that scientists seek out. Mystics exult in mystery and want it to stay mysterious. Scientists exult in mystery for a very different reason: it gives them something to do.
Admissions of ignorance and mystification are vital to good science. It is therefore galling, to say the least, when enemies of science turn those constructive admissions around and abuse them for political advantage. Worse, it threatens the enterprise of science itself. This is exactly the effect that creationism or intelligent design theory (ID) is having, especially because its propagandists are slick, superficially plausible and, above all, well financed. ID, by the way, is not a new form of creationism. It simply is creationism disguised, for political reasons, under a new name.
It isnt even safe for a scientist to express temporary doubt as a rhetorical device before going on to dispel it.
To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree. You will find this sentence of Charles Darwin quoted again and again by creationists. They never quote what follows. Darwin immediately went on to confound his initial incredulity. Others have built on his foundation, and the eye is today a showpiece of the gradual, cumulative evolution of an almost perfect illusion of design. The relevant chapter of my Climbing Mount Improbable is called The fortyfold Path to Enlightenment in honour of the fact that, far from being difficult to evolve, the eye has evolved at least 40 times independently around the animal kingdom.
The distinguished Harvard geneticist Richard Lewontin is widely quoted as saying that organisms appear to have been carefully and artfully designed. Again, this was a rhetorical preliminary to explaining how the powerful illusion of design actually comes about by natural selection. The isolated quotation strips out the implied emphasis on appear to, leaving exactly what a simple-mindedly pious audience in Kansas, for instance wants to hear.
The deceitful misquoting of scientists to suit an anti-scientific agenda ranks among the many unchristian habits of fundamentalist authors. But such Telling Lies for God (the book title of the splendidly pugnacious Australian geologist Ian Plimer) is not the most serious problem. There is a more important point to be made, and it goes right to the philosophical heart of creationism.
The standard methodology of creationists is to find some phenomenon in nature which Darwinism cannot readily explain. Darwin said: If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. Creationists mine ignorance and uncertainty in order to abuse his challenge. Bet you cant tell me how the elbow joint of the lesser spotted weasel frog evolved by slow gradual degrees? If the scientist fails to give an immediate and comprehensive answer, a default conclusion is drawn: Right, then, the alternative theory; intelligent design wins by default.
Notice the biased logic: if theory A fails in some particular, theory B must be right! Notice, too, how the creationist ploy undermines the scientists rejoicing in uncertainty. Todays scientist in America dare not say: Hm, interesting point. I wonder how the weasel frogs ancestors did evolve their elbow joint. Ill have to go to the university library and take a look. No, the moment a scientist said something like that the default conclusion would become a headline in a creationist pamphlet: Weasel frog could only have been designed by God.
I once introduced a chapter on the so-called Cambrian Explosion with the words: It is as though the fossils were planted there without any evolutionary history. Again, this was a rhetorical overture, intended to whet the readers appetite for the explanation. Inevitably, my remark was gleefully quoted out of context. Creationists adore gaps in the fossil record.
Many evolutionary transitions are elegantly documented by more or less continuous series of changing intermediate fossils. Some are not, and these are the famous gaps. Michael Shermer has wittily pointed out that if a new fossil discovery neatly bisects a gap, the creationist will declare that there are now two gaps! Note yet again the use of a default. If there are no fossils to document a postulated evolutionary transition, the assumption is that there was no evolutionary transition: God must have intervened.
The creationists fondness for gaps in the fossil record is a metaphor for their love of gaps in knowledge generally. Gaps, by default, are filled by God. You dont know how the nerve impulse works? Good! You dont understand how memories are laid down in the brain? Excellent! Is photosynthesis a bafflingly complex process? Wonderful! Please dont go to work on the problem, just give up, and appeal to God. Dear scientist, dont work on your mysteries. Bring us your mysteries for we can use them. Dont squander precious ignorance by researching it away. Ignorance is Gods gift to Kansas.
Richard Dawkins, FRS, is the Charles Simonyi Professor of the Public Understanding of Science, at Oxford University. His latest book is The Ancestors Tale
Gee, really? Then tell us, Einstein, what are these? Transitional Vertebrate Fossils FAQ.
(Reptile to Bird etc.)...
Gee, really? This sure looks like a reptile to bird transitional sequence to me (from a prior post of mine):
Theropod dinosaur to bird evolutionary transition:
The cladogram for the evolution of flight looks like this:
(Note -- each name along the top is a known transitional fossil; and those aren't all that have been discovered.) Here's a more detailed look at the middle section:
Fossils discovered in the past ten years in China have answered most of the "which came first" questions about the evolution of birds from dinosaurs.
We now know that downy feathers came first, as seen in this fossil of Sinosauropteryx:
That's a close-up of downy plumage along the backbone. Here's a shot of an entire fossil
Sinosauropteryx was reptilian in every way, not counting the feathers. It had short forelimbs, and the feathers were all the same size. Presumably, the downy feathers evolved from scales driven by a need for bodily insulation.
Next came Protarchaeopteryx:
It had long arms, broad "hands", and long claws:
Apparently this species was driven by selection to develop more efficient limbs for grasping prey. One of the interesting things about this species is that the structure of the forelimb has been refined to be quite efficient at sweeping out quickly to grab prey, snap the hands together, then draw them back towards the body (mouth?). The specific structures in question are the semilunate carpal (a wrist bone), that moves with the hand in a broad, flat, 190 degree arc, heavy chest muscles, bones of the arm which link together with the wrist so as to force the grasping hands to spread out toward the prey during the forestroke and fold in on the prey during the upstroke. Not only is this a marvelously efficient prey-grabbing mechanism, but the same mechanism is at the root of the wing flight-stroke of modern birds. Evolution often ends up developing a structure to serve one need, then finds it suitable for adaptation to another. Here, a prey-grasping motion similar in concept to the strike of a praying mantis in a reptile becomes suitable for modifying into a flapping flight motion.
Additionally, the feathers on the hands and tail have elongated, becoming better suited for helping to sweep prey into the hands.
Next is Caudipteryx:
This species had hand and tail feathers even more developed than the previous species, and longer feathers, more like that of modern birds:
However, it is clear that this was still not a free-flying animal yet, because the forelimbs were too short and the feathers not long enough to support its weight, and the feathers were symmetrical (equal sized "fins" on each side of the central quill). It also had very reduced teeth compared to earlier specimens and a stubby beak:
But the elongation of the feathers indicates some aerodynamic purpose, presumably gliding after leaping (or falling) from trees which it had climbed with its clawed limbs, in the manner of a flying squirrel. Feathers which were developed "for" heat retention and then pressed into service to help scoop prey were now "found" to be useful for breaking falls or gliding to cover distance (or swooping down on prey?).
Next is Sinornithosaurus:
Similar to the preceding species, except that the pubis bone has now shifted to point to the back instead of the front, a key feature in modern birds (when compared to the forward-facing publis bone in reptiles). Here are some of the forearm feathers in detail:
Long feathers in detail:
Next is Archaeopteryx:
The transition to flight is now well underway. Archaeopteryx has the reversed hallux (thumb) characteristic of modern birds, and fully developed feathers of the type used for flight (long, aligned with each other, and assymetrical indicating that the feathers have been refined to function aerodynamically). The feathers and limbs are easily long enough to support the weight of this species in flight. However, it lacks some structures which would make endurance flying more practical (such as a keeled sternum for efficient anchoring of the pectoral muscles which power the downstroke) and fused chest vertebrae. Archaeopteryx also retains a number of clearly reptilian features still, including a clawed "hand" emerging from the wings, small reptilian teeth, and a long bony tail. After the previous species' gliding abilities gave it an advantage, evolution would have strongly selected for more improvements in "flying" ability, pushing the species towards something more resembling sustained powered flight.
Next is Confuciusornis:
This species had a nearly modern flight apparatus. It also displays transitional traits between a reptilian grasping "hand" and a fully formed wing as in modern birds -- the outer two digits (the earlier species had three-fingered "hands") in Confuciusornis are still free, but the center digit has now formed flat, broad bones as seen in the wings of modern birds.
Additionally, the foot is now well on its way towards being a perching foot as in modern birds:
It also has a keeled sternum better suited for long flight, and a reduced number of vertebrae in the tail, on its way towards becoming the truncated tail of modern birds (which while prominent, is a small flap of muscle made to look large only because of the long feathers attached).
From this species it's only a small number of minor changes to finish the transition into the modern bird family.
(Hey, who said there are no transitional fossils? Oh, right, a lot of dishonest creationists. And there are a lot more than this, I've just posted some of the more significant milestones.)
There's been a very recent fossil find along this same lineage, too new for me to have found any online images to include in this article. And analysis is still underway to determine exactly where it fits into the above lineage. But it has well-formed feathers, which extend out from both the "arms" and the legs. Although it wasn't advanced enough to fully fly, the balanced feathering on the front and back would have made it ideally suited for gliding like a flying squirrel, and it may be another link between the stage where feathers had not yet been pressed into service as aerodynamic aids, and the time when they began to be used more and more to catch the air and developing towards a "forelimbs as wings" specialization.
So in short, to answer your question about how flight could have developed in birds, the progression is most likely some minor refinement on the following:
1. Scales modified into downy feathers for heat retention.
2. Downy feathers modified into "straight" feathers for better heat retention (modern birds still use their body "contour feathers" in this fashion).
3. Straight feathers modified into a "grasping basket" on the hands (with an accompanying increase in reach for the same purpose).
4. Long limbs with long feathers refined to better survive falls to the ground.
5. "Parachute" feathers refined for better control, leading to gliding.
6. Gliding refined into better controlled, longer gliding.
7. Long gliding refined into short powered "hops".
8. Short powered flight refined into longer powered flight.
9. Longer powered flight refined into long-distance flying.
Note that in each stage, the current configuration has already set the stage for natural selection to "prefer" individuals which better meet the requirements of the next stage. Evolution most often works like this; by taking some pre-existing ability or structure, and finding a better use for it or a better way to make it perform its current use.
archiopterix was a fully developed Bird.
Wow, what have *you* been smoking? Taking too many tokes from the creationist bong-o-propaganda, I'll bet. Tell me, what "fully developed bird" has the following reptilian features, eh? (Another former post of mine follows:)
So "it is all bird", eh? Well that explains the wings and feathers and so on. But how then do you explain these clearly reptilian features?Premaxilla and maxilla are not horn-covered. This is posh talk for "does not have a bill."[The above condensed from All About Archaeopteryx by Chris Nedin, which has far more information and quotes from primary research.
Trunk region vertebra are free. In birds the trunk vertebrae are always fused.
Pubic shafts with a plate-like, and slightly angled transverse cross-section. A Character shared with dromaeosaurs but not with other dinosaurs or birds.
Cerebral hemispheres elongate, slender and cerebellum is situated behind the mid-brain and doesn't overlap it from behind or press down on it. This again is a reptilian feature. In birds the cerebral hemispheres are stout, cerebellum is so much enlarged that it spreads forwards over the mid-brain and compresses it downwards.
Neck attaches to skull from the rear as in dinosaurs not from below as in modern birds. The site of neck attachement (from below) is characteristic in birds, _Archaeopteryx_ does not have this character, but is the same as theropod dinosaurs.
Center of cervical vertebrae have simple concave articular facets. This is the same as the archosaur pattern. In birds the vertebrae are different, they have a saddle-shaped surface: "The most striking feature of the vertebrae is the simple disk-like facets of their centra, without any sign of the saddle-shaped articulations found in other birds" (de Beer 1954, p. 17).
Long bony tail with many free vertebrae up to tip (no pygostyle). Birds have a short tail and the caudal vertebrae are fused to give the pygostyle.
Premaxilla and maxilla bones bear teeth. No modern bird possess teeth.
Ribs slender, without joints or uncinate processes and do not articulate with the sternum. Birds have stout ribs with uncinate processes (braces between them) and articulate with the sternum.
Pelvic girdle and femur joint is archosaurian rather than avian (except for the backward pointing pubis as mentioned above).
The Sacrum (the vertebrae developed for the attachment of pelvic girdle) occupies 6 vertebra. This is the same as in reptiles and especially ornithipod dinosaurs. The bird sacrum covers between 11-23 vertebrae!
Metacarpals (hand) free (except 3rd metacarpal), wrist hand joint flexible. This is as in reptiles. In birds the metacarpals are fused together with the distal carpals in the carpo-metacarpus, wrist /hand fused.
Nasal opening far forward, separated from the eye by a large preorbital fenestra (hole). This is typical of reptiles, but not of birds.
Deltoid ridge of the humerus faces anteriorly as do the radial and ulnar condyles. Typical of reptiles but not found in birds.
Claws on 3 unfused digits. No modern adult bird has 3 claws, nor do they have unfused digits.
The fibula is equal in length to the tibia in the leg. This again is a typical character of reptiles. In birds the fibula is shortened and reduced. [When you eat a chicken drumstick, the fibula is the toothpick-like sliver of bone you find lying alongside the large "legbone", which is the tibia. Ich.]
Metatarsals (foot bones) free. In birds these are fused to form the tarsometatarsus.
Gastralia present. Gastralia are "ventral ribs," elements of dermal bone in the ventral wall of the abdomen. Typical of reptiles, they are absent in birds
Are you sure you know what you're talking about?
If Evolution is True the Fossil record should have Millions of "Transitional Fossils"
It does. We will now await your admission that evolution has been supported by the evidence.
as there are many Fossils of Fully separate Species.
You're very confused, I see. Transitional forms are *also* "fully separate species". Whatever made you think they wouldn't be?
Yet there are No "Transitional" ones....NONE.
Uh huh. Sure. Here are a few of the "non-existent" transitional fossils you're incredibly ignorant about:
The above is from 29+ Evidences for Macroevolution, which compiles several hundred transitional fossils, which is itself just a *SMALL* sampling of the ENORMOUS numbers of fine transitional sequences found in the fossil record and well known to anyone who has bothered to CRACK OPEN A BOOK -- or even do a websearch -- in the past 25 years or so... So what's the anti-evolutionists' excuse for remaining abysmally ignorant of such things, and repeatedly making the false claim that there are "no" transitional fossils, etc.?
Example 2: reptile-mammals
Figure 1.4.1. The jaws of three vertebratesmammal, therapsid, and pelycosaur. A side view of three idealized skulls of mammals, therapsids (mammal-like reptiles), and pelycosaurs (early reptiles). The figure shows the differences between mammal and reptilian jaws and ear-bone structures. The jaw joint is shown as a large black dot, the quadrate (mammalian anvil or incus) is in turquoise, the articular (mammalian hammer or malleus) is in yellow, and the angular (mammalian tympanic annulus) is in pink. Note how, in the reptile, the jaw joint is formed between the blue quadrate and the yellow articular (with the pink angular close by), and how, in the mammal, the jaw joint is formed between the squamosal above and the dentary below. In the reptile, the squamosal is just above and contacting the quadrate. Advanced therapsids have two jaw joints: a reptile-like joint and a mammal-like joint (Figure based on Kardong 2002, pp. 275, reproduced with permission from the publisher, Copyright © 2002 McGraw-Hill)
We also have an exquisitely complete series of fossils for the reptile-mammal intermediates, ranging from the pelycosauria, therapsida, cynodonta, up to primitive mammalia (Carroll 1988, pp. 392-396; Futuyma 1998, pp. 146-151; Gould 1990; Kardong 2002, pp. 255-275). As mentioned above, the standard phylogenetic tree indicates that mammals gradually evolved from a reptile-like ancestor, and that transitional species must have existed which were morphologically intermediate between reptiles and mammalseven though none are found living today. However, there are significant morphological differences between modern reptiles and modern mammals. Bones, of course, are what fossilize most readily, and that is where we look for transitional species from the past. Osteologically, two major striking differences exist between reptiles and mammals: (1) reptiles have at least four bones in the lower jaw (e.g. the dentary, articular, angular, surangular, and coronoid), while mammals have only one (the dentary), and (2) reptiles have only one middle ear bone (the stapes), while mammals have three (the hammer, anvil, and stapes) (see Figure 1.4.1).
Early in the 20th century, developmental biologists discovered something that further complicates the picture. In the reptilian fetus, two developing bones from the head eventually form two bones in the reptilian lower jaw, the quadrate and the articular (see the Pelycosaur in Figure 1.4.1). Surprisingly, the corresponding developing bones in the mammalian fetus eventually form the anvil and hammer of the unique mammalian middle ear (also known more formally as the incus and malleus, respectively; see Figure 1.4.2) (Gilbert 1997, pp. 894-896). These facts strongly indicated that the hammer and anvil had evolved from these reptilian jawbonesthat is, if common descent was in fact true. This result was so striking, and the required intermediates so outlandish, that many anatomists had extreme trouble imagining how transitional forms bridging these morphologies could have existed while retaining function. Young-earth creationist Duane Gish stated the problem this way:
"All mammals, living or fossil, have a single bone, the dentary, on each side of the lower jaw, and all mammals, living or fossil, have three auditory ossicles or ear bones, the malleus, incus and stapes. ... Every reptile, living or fossil, however, has at least four bones in the lower jaw and only one auditory ossicle, the stapes. ... There are no transitional fossil forms showing, for instance, three or two jawbones, or two ear bones. No one has explained yet, for that matter, how the transitional form would have managed to chew while his jaw was being unhinged and rearticulated, or how he would hear while dragging two of his jaw bones up into his ear." (Gish 1978, p. 80)
Figure 1.4.2. A comparison of the ears of reptiles and mammals. The reptile ear is shown on the left, the mammal ear on the right. As in Figure 1.4.1, the quadrate (mammalian anvil or incus) is in turquoise and the articular (mammalian hammer or malleus) is in yellow. The stapes is shown in brown. Note how the relative arrangement of these bones is similar in both taxa, in the order of inner ear-stapes-quadrate-articular.
Gish was incorrect in stating that there were no transitional fossil forms, and he has been corrected on this gaff numerous times since he wrote these words. However, Gish's statements nicely delineate the morphological conundrum at hand. Let's review the required evolutionary conclusion. During their evolution, two mammalian middle ear bones (the hammer and anvil, aka malleus and incus) were derived from two reptilian jawbones. Thus there was a major evolutionary transition in which several reptilian jawbones (the quadrate, articular, and angular) were extensively reduced and modified gradually to form the modern mammalian middle ear. At the same time, the dentary bone, a part of the reptilian jaw, was expanded to form the major mammalian lower jawbone. During the course of this change, the bones that form the hinge joint of the jaw changed identity. Importantly, the reptilian jaw joint is formed at the intersection of the quadrate and articular whereas the mammalian jaw joint is formed at the intersection of the squamosal and dentary (see Figure 1.4.1).
How could hearing and jaw articulation be preserved during this transition? As clearly shown from the many transitional fossils that have been found (see Figure 1.4.3), the bones that transfer sound in the reptilian and mammalian ear were in contact with each other throughout the evolution of this transition. In reptiles, the stapes contacts the quadrate, which in turn contacts the articular. In mammals, the stapes contacts the incus, which in turn contacts the malleus (see Figure 1.4.2). Since the quadrate evolved into the incus, and the articular evolved into the malleus, these three bones were in constant contact during this impressive evolutionary change. Furthermore, a functional jaw joint was maintained by redundancyseveral of the intermediate fossils have both a reptilian jaw joint (from the quadrate and articular) and a mammalian jaw joint (from the dentary and squamosal). Several late cynodonts and Morganucodon clearly have a double-jointed jaw. In this way, the reptilian-style jaw joint was freed to evolve a new specialized function in the middle ear. It is worthy of note that some modern species of snakes have a double-jointed jaw involving different bones, so such a mechanical arrangement is certainly possible and functional.
Since Figure 1.4.3 was made, several important intermediate fossils have been discovered that fit between Morganucodon and the earliest mammals. These new discoveries include a complete skull of Hadrocodium wui (Luo et al. 2001) and cranial and jaw material from Repenomamus and Gobiconodon (Wang et al. 2001). These new fossil finds clarify exactly when and how the malleus, incus, and angular completely detached from the lower jaw and became solely auditory ear ossicles.
Recall that Gish stated: "There are no transitional fossil forms showing, for instance, three or two jawbones, or two ear bones" (Gish 1978, p. 80). Gish simply does not understand how gradual transitions happen (something he should understand, obviously, if he intends to criticize evolutionary theory). These fossil intermediates illustrate why Gish's statement is a gross mischaracterization of how a transitional form should look. In several of the known intermediates, the bones have overlapping functions, and one bone can be called both an ear bone and a jaw bone; these bones serve two functions. Thus, there is no reason to expect transitional forms with intermediate numbers of jaw bones or ear bones. For example, in Morganucodon, the quadrate (anvil) and the articular (hammer) serve as mammalian-style ear bones and reptilian jaw bones simultaneously. In fact, even in modern reptiles the quadrate and articular serve to transmit sound to the stapes and the inner ear (see Figure 1.4.2). The relevant transition, then, is a process where the ear bones, initially located in the lower jaw, become specialized in function by eventually detaching from the lower jaw and moving closer to the inner ear.
Figure 1.4.3. A comparison of the jawbones and ear-bones of several transitional forms in the evolution of mammals. Approximate stratigraphic ranges of the various taxa are indicated at the far left (more recent on top). The left column of jawbones shows the view of the left jawbone from the inside of the mouth. The right column is the view of the right jawbone from the right side (outside of the skull). As in Figure 1.4.1, the quadrate (mammalian anvil or incus) is in turquoise, the articular (mammalian hammer or malleus) is in yellow, and the angular (mammalian tympanic annulus) is in pink. For clarity, the teeth are not shown, and the squamosal upper jawbone is omitted (it replaces the quadrate in the mammalian jaw joint, and forms part of the jaw joint in advanced cynodonts and Morganucodon). Q = quadrate, Ar = articular, An = angular, I = incus (anvil), Ma = malleus (hammer), Ty = tympanic annulus, D = dentary. (Reproduced from Kardong 2002, pp. 274, with permission from the publisher, Copyright © 2002 McGraw-Hill)
Here's another look:
(The above is from The Fossil Record: Evolution or "Scientific Creation", which is yet ANOTHER source the anti-evolutionists are obviously completely ignorant of -- not that that stops them from spouting off falsehoods about the subject anyway...
As previously stated, a succession of transitional fossils exists that link reptiles (Class Reptilia) and mammals (Class Mammalia). These particular reptiles are classifie as Subclass Synapsida. Presently, this is the best example of th e transformation of one major higher taxon into another. The morphologic changes that took place are well documented by fossils, beginning with animals essentially 100% reptilian and resulting in animals essentially 100% mammalian. Therefore, I have chosen this as the example to summarize in more detail (Table 1, Fig. 1).
Skulls and jaws of synapsid reptiles and mammals; left column side view of skull; center column top view of skull; right column side view of lower jaw. Hylonomus modified from Carroll (1964, Figs. 2,6; 1968, Figs. 10-2, 10-5; note that Hylonomus is a protorothyrod, not a synapsid). Archaeothyris modified from Reisz (1972, Fig. 2). Haptodus modified from Currie (1977, Figs, 1a, 1b; 1979, Figs. 5a, 5b). Sphenacodo n modified from Romer & Price (1940, Fig. 4f), Allin (1975, p. 3, Fig. 16);note: Dimetrodon substituted for top view; modified from Romer & Price, 1940, pl. 10. Biarmosuchus modified from Ivakhnenko et al. (1997, pl. 65, Figs. 1a, 1B, 2); Alin & Hopson (1992; Fig. 28.4c); Sigogneau & Tchudinov (1972, Figs. 1, 15). Eoarctops modified from Broom (1932, Fig. 35a); Boonstra (1969, Fig. 18). Pristerognathus modified from Broom (1932, Figs 17a, b,c); Boonstra (1963, Fig. 5d). Procynosuchus modified from Allin & Hopson (1992, Fig. 28.4e); Hopson (1987, Fig. 5c); Brink (1963, Fig. 10a); Kemp (1979, Fig. 1); Allin (1975, p. 3, Fig. 14). Thrinaxodon modified from Allin & Hopson (1992, Fig. 28.4f);Parrington (1946, Fig. 1); Allin (1975, p. 3, Fig. 13). Probainognathus modified from Allin & Hopson (1992, Fig. 28.4g); Romer (1970, Fig. 1); Allin (1975, p. 3, Fig. 12). Morga nucodon modified from Kermack, Mussett, & Rigney (1981, Figs. 95, 99a; 1973, Fig. 7a); Allin (1975, p. 3, Fig. 11). Asioryctes modified from Carroll (1988, Fig. 20-3b). Abbreviations: ag = angular; ar = articular; cp = coronoid process; d = dentary; f = lateral temporal fenestra; j = jugal; mm = attachment site for mammalian jaw muscles; o = eye socket; po = post orbital; q = quadrate; rl = reflected lamina; sq = squamosal; ty = tympanic.
TAXONOMY LATERAL TEMPORAL FENESTRA LOWER JAW DENTARY TEETH LOWER JAW: POST- DENTARY BONES MIDDLE EAR & JAW ARTICULATION M: Early Placental mammals
Merged with eye socket; cheek arch bowed out laterally 100% of jaw length is the den- tary; condylar process in contact with squamosal Fully differentiated teeth; incisors, canines, premolars; one tooth replacement No post-dentary bones 3 middle ear bones (stapes, incus, malleus) + tympanic; squamosal-dentary jaw joint L: "Pantothere" mammals
X 100% of jaw length is the den- tary; condylar process contacts squamosal Fully differentiated teeth; incisors, canines, premolars; one tooth replacement Post-dentary bones migrated to middle ear Probably 3 middle ear bones (stapes, incus, malleus) + tympanic; squamosal-dentary jaw joint K: Morganucodontid mammals
Morganucodon Upper Triassic & Lower Jurassic
Merged with eye socket; cheeck arch bowed out laterally 100% of jaw length is the den- tary; condylar process expanded posteriorly to make contact with squamosal Fully differentiated teeth; incisors, canines, premolars; one tooth replacement 20% of jaw length; reflected lamina decreased to narrow ribbon-like horseshoe Stapes extends from inner ear capsule to quadrate; quadrate tiny; both quadrate-articular and squamosal-dentary jaw joints J: Chiniquodontid cynodonts
Much larger than eye socket; 40- 45% of skull length; expanded posterioirly, medially, & laterally; midline of skull narrow sagittal crest; chek arch bowed out laterally 95% of jaw length is the dentary; large coronoid process expanded posteriorly; condylar process expanded posteriorly Large single canine; cheek teeth multicusped; tooth replacement reduced 20% of jaw length; angular notch widened ventrally; width of main part of angular decreased; reflec - ted lamina decreased to narrow ribbon-like horseshoe Stapes extends from inner ear capsule to quadrate; quadrate tiny; quadrate-articular joint I:Galesaurid cynodonts
Much larger than eye socket; 40% of skull length; expanded pos- terioirly, medially, & laterally; midline of skull narrow sagittal crest; chek arch bowed out laterally 85% of jaw length is the dentary; large coronoid process expanded to top of eye socket and pos- teriorly; jaw muscles attached to most of coronoid process Large single canine; cheek teeth multicusped; tooth replacement reduced 25% of jaw length; angular notch widened ventrally; width of reflec- ted lamina decreased; width of main part of angular decreased Stapes extends from inner ear capsule to quadrate; quadrate small; quadrate-articular jaw joint H: Procynosuchid cynodonts
upper Upper Permian
Much larger than eye socket; 40% of skull length; expanded pos- terioirly, medially, & laterally; midline of skull narrow sagittal crest; chek arch bowed out laterally 75-80% of jaw length is the den- tary; coronoid process expanded to near top of eye socket and posteriorly; jaw muscles attached to dorsal part of coronoid process Large single canine; cheek teeth multicusped 30% of jaw length; angular notch widened ventrally; width of reflected lamina decreased Stapes extends from inner ear capsule to quadrate; quadrate small; quadrate-articular jaw joint G: Early Therocephalians
lower Upper Permian
Larger than eye socket; expanded posteriorly and medially; 30% of skull length 75-80% of jaw length is the den- tary; posterior end of dentary expanded posteriorly and dorsally into narrow blade-like coronoid process; rises to middle of eye socket Large single canine; other teeth simple cones. 35% of jaw length; angular notch deepened into a cleft; reflected lamina large, broad, blade-like Stapes extends from inner ear capsule to quadrate; quadrate small; quadrate-articular jaw joint F: Early Gorgonopsians
lower Upper Permian
Slightly larger than eye socket; expanded posteriorly and medially (minimal); 20-25% of skull length 65-75% of jaw length is the den- tary; posterior end of dentary slightly expanded posteriorly and dorsally as incipient coronoid process Large single canine; other teeth simple cones. 40% of jaw length; angular notch deepened into a cleft; reflected lamina large, broad, blade-like Stapes extends from inner ear capsule to quadrate; quadrate- articular jaw joint E: Eotitanosuchians
Small; slightly smaller than eye socket; slightly expanded posteriorly and medially 65-75% of jaw length is the den- tary; posterodorsal edge rises broadly but slightly above tooth row Large single canine; other teeth simple cones. 40% of jaw length; angular notch deepened into a cleft; reflected lamina large, broad, blade-like Stapes extends from inner ear capsule to quadrate; quadrate- articular jaw joint D: Late sphenacodonts
Small; smaller than eye socket; confined to one side of skull 65% of jaw length is the dentary; posterodorsal edge rises broadly but slightly above the tooth row Enlarged incipient canines; other teeth simple cones 60% of jaw length; venntral edge of angular notched ("angular notch") offsetting a short pro- tusion (reflected lamina) Stapes extends from inner ear capsule to quadrate; quadrate large and plate-like; quadrate- articular jaw joint C: Early spenacodonts
Tiny; smaller than eye socket; confined to one side of skull 65-75% of jaw length is the den- tary; posterodorsal edge rises broadly but slightly above tooth row Undifferentiated; slightly enlarged incipient canines just behind nares 70% of jaw length; ventral edge of angular with shallow indentation Stapes extends from inner ear capsule to quadrate; quadrate- articular jaw joint B: Early ophiacodonts
upper Middle Pennsylvanian
Tiny; smaller than eye socket; confined to one side of skull x Undifferentiated; slightly enlarged incipient canines just behind nares x Stapes extends from inner ear capsule to quadrate; quadrate- articular jaw joint A: Protorothyrids
lower Middle Pennsylvanian
Absent 65-75% of jaw length is the den- tary; posterodorsal edge rises broadly but slightly above tooth row Undifferentiated; slightly enlarged incipient canines just behind nares 70% of jaw length; ventral edge of angular continuous Stapes extends from inner ear capsule to quadrate; quadrate- articular jaw joint
Table 1: Morphology of synapsid reptiles and mammals (Note that Hylonomus is a protothyrid, not a synapsid). Data from references cited in text.
Modern reptiles and mammals are very distinctive, easily diagnosable, and do not intergrade. Reptiles are covered by scales, mammals by hair; reptiles are cold-blooded, mammals warm-blooded; reptiles do not suckle their young, mammals have mammary glands; reptiles have sprawling posture, mammals have upright posture. Most of these features are soft part anatomy or physiology that very rarely fossilize (although dinosaur skin impressions are known from Cretaceous sediments, and imprints of mammal hair are known from Eocene bats from Germany; Franzen, 1990). In the fossil record, we must look to skeletal features.
There are many skeletal features which allow us to distinguish the reptiles from the mammals (Carroll, 1988; Table 1, rows A, M). The single most important defining characteristic is the nature of the articulation of the lower jaw to the skull (Simpson, 1959). In reptiles, multiple bones comprise the lower jaw. A small bone at the posterior end of the lower jaw, the articular, articulates with the quadrate bone of the skull (Simpson, 1959; Carroll, 1988). In mammals, one large bone, the dentary, comprises the lower jaw. It articulates with the squamosal bone of the skull (Simpson, 1959; Carroll, 1988).
From comparative anatomy studies, it is certain that most of the bones of the reptiles and mammals are homologous (Crompton & Parker, 1978; Carroll, 1988). Of greatest importance, the middle ear bones of mammals (stapes, incus, malleus, and tympanic) are homologous with several of the skull and jaw bones of reptiles (stapes, quadrate, articular, and angular, respectively; Romer, 1956, p. 33-38, 1970a; Allin, 1975, 1986; Allin & Hopson, 1992; Crompton & Parker, 1978; Hopso n, 1987, 1994; Carroll, 1988). One group of reptiles, the synapsids (Subclass Synapsida), share with the mammals an additional homologous structure: the lateral temporal fenestra, which is an opening in the skull behind the eye socket at the triple junction between the squamosal, jugal , and post orbital bones (Broom, 1932; Frazetta, 1968; Kemp, 1982; Carroll, 1988). A band of bone composed of the jugal and the squamosal is adjacent to the lateral temporal fenestra (Broom, 1932; Kemp, 1982; Carroll, 1988). This is the cheek arch so characteristic of mammal skulls (Broom, 1932; Kemp, 1982; Carroll, 1988). Therefore, synapsids are commonly named the mammal-like reptiles.
The presence of diagnosable morphologic differences between reptiles (including the oldest reptiles and the oldest synapsids) and mammals distinguishes them as distinct taxa. This allows us to test evolution by looking for transitional forms between the two. Because many of the bones are homologous, we should find evidence illustrating how these bones were modified over time to become the new bones. Furthermore, these morphologic changes should happen in parallel and in geochronologic succession.
Synapsid reptiles inhabited Pangea from the Middle Pennsylvanian through the Early Jurassic (Kemp, 1982, 1985; Sloan, 1983; Carroll, 1988; Hopson, 1969, 1987, 1994; Hopson & Crompton, 1969; Hotton, et al., 1986; Crompton & Jenkins, 1973; Sidor & Hopson, 1998; Romer & Price, 1940; Broom, 1932; Boonstra, 1963, 1969, 1971; Tchudinov, 1983; Olson, 1944; Tatarinov, 1974; Vyushkov, 1955; Efremov, 1954). From the Early Permian through the Early Triassic, they were the largest and most abundant land animals (Sloan, 1983; Colbert, 1965). Though much less well known to the general public than dinosaurs, one of the cereal box dinosaurs, Dimetrodon (the sail-backed reptile), is a synapsid, not a dinosaur (Romer & Price, 1940; Carroll, 1988). The oldest mammals are Late Triassic (Kemp, 1982; Carroll, 1988). Below is a discussion of the geochronologic succession linking synapsids and mammals. The oldest reptiles (named protorothyrids; Carroll, 1964, 1988, p. 192-199) are from the lower Middle Pennsylvanian, and the oldest synapsids (Reisz, 1972) are from the upper Middle Pennsylvanian, both of Nova Scotia. Upper Pennsylvanian and Lower Permian forms are known primarily from the midcontinent and Permian Basin region of the United States (Romer & Price, 1940; Currie, 1977, 1979; Kemp, 1982; Sloan, 1983). The basal Upper Permian forms are known from Russia (Tchudinov, 1960, 1983; Efremov, 1954; Olson, 1962; Sigogneau & Tchudinov, 1972; Ivakhnenko et al., 1997). Most of the Upper Permian and Lower Triassic succession is known from southern Africa, especially the Great Karoo of South Africa (Broom, 1932; Boonstra, 1963, 1969, 1971; Hopson & Kitching, 1972; Kemp, 1982; Sloan, 1983). The Middle Triassic forms are from South America (Romer, 1969a, 1969b, 1970b, 1973; Romer & Lewis, 1973; Bonaparte & Barbarena, 1975), and the Upper Triassic and Lower Jurassic mammals are known from Eurasia (Kermack, Mussett, & Rigney, 1973, 1981; Kemp, 1982). Subsequent Mesozoic mammals are known from all over the world (Simpson, 1928; Lillegraven et al., 1979).
When placed in proper geochronologic succession, the synapsids naturally form a succession of taxa (genera and families) that progressively become more mammal-like and less reptile-like (Kemp, 1982, 1985; Sloan, 1983; Sidor & Hopson, 1998; Hopson, 1987, 1994). Morphologic changes, summarized in Table 1 and Figure 1, affect the entire skeletal anatomy of these animals, but are most clearly displayed in their skulls.
The lateral temporal fenestra increased in size from a tiny opening smaller than the eye socket to a giant opening occupying nearly half the length of the skull. Ultimately, it merged with the eye socket, thus producing the full development of the cheek arch so characteristic of mammals (Broom, 1932; Frazetta, 1968; Kemp, 1982; Sloan, 1983; Hopson, 1987, 1994; Carroll, 1988).
Successively, the relative proportion of the lower jaw comprised of the dentary bone (teeth-bearing bone) gradually increased until the entire lower jaw consisted of the dentary (Kemp, 1982; Sloan, 1983; Carroll, 1988; Hopson, 1987, 1994). In Pennsylvanian and Lower and basal Upper Permian synapsids, the postero-dorsal edge of the lower jaw rose broadly but only slightly above the level of the tooth row (Romer & Price, 1940; Currie, 1977, 1979; Ivakhnenko et al., 1997; Tchudinov, 1960, 1983; Efremov, 1954; Olson, 1962; Sigogneau & Tchudinov, 1972; Hopson, 1987, 1994). In succeeding forms, the posterior part of the dentary expanded dorsally and posteriorly as a blade-like process, and progressively became larger (Broom, 1932; Boonstra, 1963, 1969, 1971; Sigogneau, 1970; Brink, 1963; Kemp, 1979; Hopson, 1987, 1994), forming the coronoid process (Parrington, 1946; Fourie, 1974; Romer, 1969b, 1970b, 1973; Hopson, 1987, 1994) to which the mammalian-type jaw musculature is attached (Barghusen, 1968; Bramble, 1978; Crompton, 1972; Crompton & Parker, 1978; Kemp, 1982; Sloan, 1983; Carroll, 1988). Concomitantly, the post-dentary bones progressively reduced in size (Allin, 1975; Crompton, 1972; Crompton & Parker, 1978; Kemp, 1982; Sloan, 1983; Carroll, 1988; Hopson, 1987, 1994).
Beginning with the Upper Pennsylvanian sphenacodonts, a notch developed in the angular bone that offsets a projection, the reflected lamina (Allin, 1975; Allin & Hopson, 1992; Hopson, 1987, 1994; Romer & Price, 1940; Currie, 1977, 1979; Kemp, 1982; Sloan, 1983; Carroll, 1988). The reflected lamina first became a large blade-like flange (Allin, 1975; Allin & Hopson, 1992; Hopson, 1987, 1994; Ivakhnenko et al., 1997; Tchudinov, 1960, 1983; Efremov, 1954; Olson, 1962; Sigogneau & Tchudinov, 1972; Broom, 1932; Sigogneau, 1970; Boonstra, 1963, 1969, 1971), and then was progressively reduced to a delicate horseshoe-shaped bone (Allin, 1975; Allin & Hopson, 1992; Hopson, 1987, 1994; Brink, 1963; Parrington, 1946; Fourie, 1974; Romer, 1969b, 1970b, 1973; Kermack, Mussett, & Rigney, 1973, 1981; Kemp, 1979, 1982; Sloan, 1983; Carroll, 1988).
Simultaneously, the quadrate progressively decreased in size (Allin, 1975; Allin & Hopson, 1992; Hopson, 1987, 1994; Kemp, 1982; Sloan, 1983; Carroll, 1988). The articular did not decrease in size much, being small initially, but developed a downward-pointing prong (Allin, 1975; Allin & Hopson, 1992; Hopson, 1987, 1994; Kemp, 1982; Sloan, 1983; Carroll, 1988). In the synapsids, the lower jaw was hinged to the skull by the articular and quadrate bones (Crompton, 1972; Crompton & Parker, 1978; Allin, 1975; Allin & Hopson, 1992; Hopson, 1987, 1994). Thus they are classified as reptiles (Simpson, 1959; Kemp, 1982; Sloan, 1983; Carroll, 1988). As the quadrate and articular became smaller, they were relieved of their solid suture to the dentary and skull (Crompton, 1972; Allin, 1975, 1986; Allin & Hopson, 1992; Hopson, 1987, 1994; Crompton & Parker, 1978; Kemp, 1982; Sloan, 1983; Carroll, 1988). A projection of the dentary extended posteriorly and made contact with the squamosal. Morganucodon possessed the mammalian dentary-squamosal jaw joint adjacent to the reptilian articular-quadrate jaw joint (Kermack, Mussett, & Rigney, 1973, 1981; Carroll, 1988). It is classified as the first mammal, but it is a perfect intermediate. Now that a new jaw joint was established, the quadrate and articular were subsequently relieved of that function (Crompton, 1972; Allin, 1975, 1986; Allin & Hopson, 1992; Hopson, 1987, 1994; Crompton & Parker, 1978; Kemp, 1982; Sloan, 1983; Carroll, 1988). Ultimately, in Middle and Upper Jurassic mammals, the tiny quadrate, articular, and ring-like angular migrated as a unit to the middle ear where they joined the stapes and became the incus, malleus, and tympanic bones (Allin, 197 5, 1986; Allin & Hopson, 1992; Hopson, 1987, 1994; Kemp, 1982; Sloan, 1983; Carroll, 1988).
Progressively, the teeth became differentiated. The large canines developed first, followed by the development of multicusped cheek teeth, reduced tooth replacement (Osborn & Crompton, 1973; Crompton & Parker, 1978), and finally full y differentiated incisors, canines, premolars, and molars with one tooth replacement during life (Kemp, 1982; Hopson, 1994).
Many other morphologic changes are documented in the fossil record. These demonstrate the morphologic and geochronologic succession from sprawling limb posture to upright limb posture of mammals (Jenkins, 1971; Romer & Lewis, 197 3; Kemp, 1982; Carroll, 1988; Hopson, 1994). As Jenkins (1971, p. 210) stated, In details of morphology and function, the cynodont post-cranial skeleton should be regarded as neither reptilian nor mammalian but as transitional between the two classes . Other changes have been adequately summarized elsewhere (Kemp, 1982; Sloan, 1983; Carroll, 1988; Hopson, 1994). Obviously, fundamental physiologic changes must have taken place as well, many of which are not directly preserved in the fossil record, though some can be inferred from the skeletal anatomy (Findlay, 1968; Kemp, 1982; Sloan, 1983, Carroll, 1988; Hopson, 1994).
This is well documented in the fossil record by a massive volume of incontrovertible data that cannot be explained away. Such large-scale, progressive, continuous, gradual, and geochronologically successive morphologic change (Sidor & Hopson, 1998) is descent with modification, and provides compelling evidence for evolution on a grand scale.
Tell me, of any two consecutive fossils in the following list, do any differ so much from each other that anti-evolutionists wouldn't just write it off as "just adaptation", or "just microevolution"? [All of the listed specimens are actual fossils]
(Most of the above text is from The Transitional Vertebrate Fossils FAQ, and is the result of hard work by Kathleen Hunt, who deserves the credit. I've just extracted the relevant individual portions and assembled them into one direct fish-to-elephant sequence.) If you like that, here are a few hundred more.
Fish to Amphibian transition:
1. Cheirolepis, (early Devonian, 400 million years ago) -- Primitive bony ray-finned fishes that gave rise to the vast majority of living fish. Heavy acanthodian-type scales, acanthodian-like skull, and big notocord.
2. Osteolepis (mid-Devonian, 390 million years ago) -- One of the earliest crossopterygian lobe-finned fishes, still sharing some characters with the lungfish (the other lobe-finned fishes). Had paired fins with a leg-like arrangement of major limb bones, capable of flexing at the "elbow", and had an early-amphibian-like skull and teeth.
3. Eusthenopteron, Sterropterygion (mid-late Devonian, 380 million years ago) -- Early rhipidistian lobe-finned fish roughly intermediate between early crossopterygian fish and the earliest amphibians. Skull very amphibian-like. Strong amphibian- like backbone. Fins very like early amphibian feet in the overall layout of the major bones, muscle attachments, and bone processes, with tetrapod-like tetrahedral humerus, and tetrapod-like elbow and knee joints. But there are no perceptible "toes", just a set of identical fin rays. Body & skull proportions rather fishlike.
4. Panderichthys, Elpistostege (mid-late Devonian, about 370 Mya) -- These "panderichthyids" are very tetrapod-like lobe-finned fish. Unlike Eusthenopteron, these fish actually look like tetrapods in overall proportions (flattened bodies, dorsally placed orbits, frontal bones! in the skull, straight tails, etc.) and have remarkably foot-like fins.
5. Obruchevichthys(middle Late Devonian, about 370 Mya -- Discovered in 1991 in Scotland, these are the earliest known tetrapod remains. The humerus is mostly tetrapod-like but retains some fish features. The discoverer, Ahlberg (1991), said: "It [the humerus] is more tetrapod-like than any fish humerus, but lacks the characteristic early tetrapod 'L-shape'...this seems to be a primitive, fish-like character....although the tibia clearly belongs to a leg, the humerus differs enough from the early tetrapod pattern to make it uncertain whether the appendage carried digits or a fin. At first sight the combination of two such extremities in the same animal seems highly unlikely on functional grounds. If, however, tetrapod limbs evolved for aquatic rather than terrestrial locomotion, as recently suggested, such a morphology might be perfectly workable."
6. Hynerpeton, Acanthostega, Ichthyostega (late Devonian, 360 Mya) -- A little later, the fin-to-foot transition was almost complete, and we have a set of early tetrapod fossils that clearly did have feet. The most complete are Ichthyostega, Acanthostega gunnari, and the newly described Hynerpeton bassetti (Daeschler et al., 1994). (There are also other genera known from more fragmentary fossils.) Hynerpeton is the earliest of these three genera (365 Ma), but is more advanced in some ways; the other two genera retained more fish- like characters longer than the Hynerpeton lineage did. Acanthostega still had internal gills, adding further support to the suggestion that unique tetrapod characters such as limbs with digits evolved first for use in water rather than for walking on land. Acanthostega also had a remarkably fish-like shoulder and forelimb. Ichthyostega was also very fishlike, retaining a fish-like finned tail, permanent lateral line system, and notochord. It turns out that Acanthostega's front foot had eight toes, and Ichthyostega's hind foot had seven toes, giving both feet the look of a short, stout flipper with many "toe rays" similar to fin rays. All you have to do to a lobe- fin to make it into a many-toed foot like this is curl it, wrapping the fin rays forward around the end of the limb. In fact, this is exactly how feet develop in larval amphibians, from a curled limb bud. Hynerpeton, in contrast, probably did not have internal gills and already had a well-developed shoulder girdle; it could elevate and retract its forelimb strongly, and it had strong muscles that attached the shoulder to the rest of the body (Daeschler et al., 1994).
7. Labyrinthodonts (eg Pholidogaster, Pteroplax) (late Dev./early Miss., 355 Mya) -- These larger amphibians still have some icthyostegid fish features, such as skull bone patterns, labyrinthine tooth dentine, presence & pattern of large palatal tusks, the fish skull hinge, pieces of gill structure between cheek & shoulder, and the vertebral structure. But they have lost several other fish features: the fin rays in the tail are gone, the vertebrae are stronger and interlocking, the nasal passage for air intake is well defined, etc.
Amphibian to Reptile transition:
8. Pholidogaster (Mississippian, about 330 Ma) -- A group of large labrinthodont amphibians, transitional between the early amphibians (the ichthyostegids, described above) and later amphibians such as rhachitomes and anthracosaurs.
9. Proterogyrinus (late Mississippian, 325 Mya) -- Classic labyrinthodont-amphibian skull and teeth, but with reptilian vertebrae, pelvis, humerus, and digits. Still has fish skull hinge. Amphibian ankle. 5-toed hand and a 2-3-4-5-3 (almost reptilian) phalangeal count.
10. Limnoscelis, Tseajaia (late Carboniferous, 300 Mya) -- Amphibians apparently derived from the early anthracosaurs, but with additional reptilian features: structure of braincase, reptilian jaw muscle, expanded neural arches.
11. Solenodonsaurus (mid-Pennsylvanian) -- An incomplete fossil, apparently between the anthracosaurs and the cotylosaurs. Loss of palatal fangs, loss of lateral line on head, etc. Still just a single sacral vertebra, though.
12. Hylonomus, Paleothyris (early Pennsylvanian) -- These are protorothyrids, very early cotylosaurs (primitive reptiles). They were quite little, lizard-sized animals with amphibian-like skulls (amphibian pineal opening, dermal bone, etc.), shoulder, pelvis, & limbs, and intermediate teeth and vertebrae. Rest of skeleton reptilian, with reptilian jaw muscle, no palatal fangs, and spool-shaped vertebral centra. Probably no eardrum yet.
13. Paleothyris (early Pennsylvanian) -- An early captorhinomorph reptile, with no temporal fenestrae at all.
14. Protoclepsydrops haplous (early Pennsylvanian) -- The earliest known synapsid reptile. Little temporal fenestra, with all surrounding bones intact. Had amphibian-type vertebrae with tiny neural processes. (reptiles had only just separated from the amphibians)
15. Clepsydrops (early Pennsylvanian) -- The second earliest known synapsid.
Reptile to Mammal transition:
16. Archaeothyris (early-mid Pennsylvanian) -- A slightly later ophiacodont. Small temporal fenestra, now with some reduced bones (supratemporal). Braincase still just loosely attached to skull. Slight hint of different tooth types. Still has some extremely primitive, amphibian/captorhinid features in the jaw, foot, and skull. Limbs, posture, etc. typically reptilian, though the ilium (major hip bone) was slightly enlarged.
17. Varanops (early Permian) -- Temporal fenestra further enlarged. Braincase floor shows first mammalian tendencies & first signs of stronger attachment to rest of skull (occiput more strongly attached). Lower jaw shows first changes in jaw musculature (slight coronoid eminence). Body narrower, deeper: vertebral column more strongly constructed. Ilium further enlarged, lower-limb musculature starts to change (prominent fourth trochanter on femur). This animal was more mobile and active. Too late to be a true ancestor, and must be a "cousin".
18. Haptodus (late Pennsylvanian) -- One of the first known sphenacodonts, showing the initiation of sphenacodont features while retaining many primitive features of the ophiacodonts. Occiput still more strongly attached to the braincase. Teeth become size-differentiated, with biggest teeth in canine region and fewer teeth overall. Stronger jaw muscles. Vertebrae parts & joints more mammalian. Neural spines on vertebrae longer. Hip strengthened by fusing to three sacral vertebrae instead of just two. Limbs very well developed.
19. Dimetrodon, Sphenacodon or a similar sphenacodont (late Pennsylvanian to early Permian, 270 Ma) -- More advanced pelycosaurs, clearly closely related to the first therapsids (next). Dimetrodon is almost definitely a "cousin" and not a direct ancestor, but as it is known from very complete fossils, it's a good model for sphenacodont anatomy. Medium-sized fenestra. Teeth further differentiated, with small incisors, two huge deep- rooted upper canines on each side, followed by smaller cheek teeth, all replaced continuously. Fully reptilian jaw hinge. Lower jaw bone made of multiple bones & with first signs of a bony prong later involved in the eardrum, but there was no eardrum yet, so these reptiles could only hear ground-borne vibrations (they did have a reptilian middle ear). Vertebrae had still longer neural spines (spectacularly so in Dimetrodon, which had a sail), and longer transverse spines for stronger locomotion muscles.
20. Biarmosuchia (late Permian) -- A therocephalian -- one of the earliest, most primitive therapsids. Several primitive, sphenacodontid features retained: jaw muscles inside the skull, platelike occiput, palatal teeth. New features: Temporal fenestra further enlarged, occupying virtually all of the cheek, with the supratemporal bone completely gone. Occipital plate slanted slightly backwards rather than forwards as in pelycosaurs, and attached still more strongly to the braincase. Upper jaw bone (maxillary) expanded to separate lacrymal from nasal bones, intermediate between early reptiles and later mammals. Still no secondary palate, but the vomer bones of the palate developed a backward extension below the palatine bones. This is the first step toward a secondary palate, and with exactly the same pattern seen in cynodonts. Canine teeth larger, dominating the dentition. Variable tooth replacement: some therocephalians (e.g Scylacosaurus) had just one canine, like mammals, and stopped replacing the canine after reaching adult size. Jaw hinge more mammalian in position and shape, jaw musculature stronger (especially the mammalian jaw muscle). The amphibian-like hinged upper jaw finally became immovable. Vertebrae still sphenacodontid-like. Radical alteration in the method of locomotion, with a much more mobile forelimb, more upright hindlimb, & more mammalian femur & pelvis. Primitive sphenacodontid humerus. The toes were approaching equal length, as in mammals, with #toe bones varying from reptilian to mammalian. The neck & tail vertebrae became distinctly different from trunk vertebrae. Probably had an eardrum in the lower jaw, by the jaw hinge.
21. Procynosuchus (latest Permian) -- The first known cynodont -- a famous group of very mammal-like therapsid reptiles, sometimes considered to be the first mammals. Probably arose from the therocephalians, judging from the distinctive secondary palate and numerous other skull characters. Enormous temporal fossae for very strong jaw muscles, formed by just one of the reptilian jaw muscles, which has now become the mammalian masseter. The large fossae is now bounded only by the thin zygomatic arch (cheekbone to you & me). Secondary palate now composed mainly of palatine bones (mammalian), rather than vomers and maxilla as in older forms; it's still only a partial bony palate (completed in life with soft tissue). Lower incisor teeth was reduced to four (per side), instead of the previous six (early mammals had three). Dentary now is 3/4 of lower jaw; the other bones are now a small complex near the jaw hinge. Jaw hinge still reptilian. Vertebral column starts to look mammalian: first two vertebrae modified for head movements, and lumbar vertebrae start to lose ribs, the first sign of functional division into thoracic and lumbar regions. Scapula beginning to change shape. Further enlargement of the ilium and reduction of the pubis in the hip. A diaphragm may have been present.
22. Dvinia [also "Permocynodon"] (latest Permian) -- Another early cynodont. First signs of teeth that are more than simple stabbing points -- cheek teeth develop a tiny cusp. The temporal fenestra increased still further. Various changes in the floor of the braincase; enlarged brain. The dentary bone was now the major bone of the lower jaw. The other jaw bones that had been present in early reptiles were reduced to a complex of smaller bones near the jaw hinge. Single occipital condyle splitting into two surfaces. The postcranial skeleton of Dvinia is virtually unknown and it is not therefore certain whether the typical features found at the next level had already evolved by this one. Metabolic rate was probably increased, at least approaching homeothermy.
23. Thrinaxodon (early Triassic) -- A more advanced "galesaurid" cynodont. Further development of several of the cynodont features seen already. Temporal fenestra still larger, larger jaw muscle attachments. Bony secondary palate almost complete. Functional division of teeth: incisors (four uppers and three lowers), canines, and then 7-9 cheek teeth with cusps for chewing. The cheek teeth were all alike, though (no premolars & molars), did not occlude together, were all single- rooted, and were replaced throughout life in alternate waves. Dentary still larger, with the little quadrate and articular bones were loosely attached. The stapes now touched the inner side of the quadrate. First sign of the mammalian jaw hinge, a ligamentous connection between the lower jaw and the squamosal bone of the skull. The occipital condyle is now two slightly separated surfaces, though not separated as far as the mammalian double condyles. Vertebral connections more mammalian, and lumbar ribs reduced. Scapula shows development of a new mammalian shoulder muscle. Ilium increased again, and all four legs fully upright, not sprawling. Tail short, as is necessary for agile quadrupedal locomotion. The whole locomotion was more agile. Number of toe bones is 188.8.131.52.3, intermediate between reptile number (184.108.40.206.4) and mammalian (220.127.116.11.3), and the "extra" toe bones were tiny. Nearly complete skeletons of these animals have been found curled up - a possible reaction to conserve heat, indicating possible endothermy? Adults and juveniles have been found together, possibly a sign of parental care. The specialization of the lumbar area (e.g. reduction of ribs) is indicative of the presence of a diaphragm, needed for higher O2 intake and homeothermy. NOTE on hearing: The eardrum had developed in the only place available for it -- the lower jaw, right near the jaw hinge, supported by a wide prong (reflected lamina) of the angular bone. These animals could now hear airborne sound, transmitted through the eardrum to two small lower jaw bones, the articular and the quadrate, which contacted the stapes in the skull, which contacted the cochlea. Rather a roundabout system and sensitive to low-frequency sound only, but better than no eardrum at all! Cynodonts developed quite loose quadrates and articulars that could vibrate freely for sound transmittal while still functioning as a jaw joint, strengthened by the mammalian jaw joint right next to it. All early mammals from the Lower Jurassic have this low-frequency ear and a double jaw joint. By the middle Jurassic, mammals lost the reptilian joint (though it still occurs briefly in embryos) and the two bones moved into the nearby middle ear, became smaller, and became much more sensitive to high-frequency sounds.
24. Cynognathus (early Triassic, 240 Ma; suspected to have existed even earlier) -- We're now at advanced cynodont level. Temporal fenestra larger. Teeth differentiating further; cheek teeth with cusps met in true occlusion for slicing up food, rate of replacement reduced, with mammalian-style tooth roots (though single roots). Dentary still larger, forming 90% of the muscle-bearing part of the lower jaw. TWO JAW JOINTS in place, mammalian and reptilian: A new bony jaw joint existed between the squamosal (skull) and the surangular bone (lower jaw), while the other jaw joint bones were reduced to a compound rod lying in a trough in the dentary, close to the middle ear. Ribs more mammalian. Scapula halfway to the mammalian condition. Limbs were held under body. There is possible evidence for fur in fossil pawprints.
25. Diademodon (early Triassic, 240 Ma; same strata as Cynognathus) -- Temporal fenestra larger still, for still stronger jaw muscles. True bony secondary palate formed exactly as in mammals, but didn't extend quite as far back. Turbinate bones possibly present in the nose (warm-blooded?). Dental changes continue: rate of tooth replacement had decreased, cheek teeth have better cusps & consistent wear facets (better occlusion). Lower jaw almost entirely dentary, with tiny articular at the hinge. Still a double jaw joint. Ribs shorten suddenly in lumbar region, probably improving diaphragm function & locomotion. Mammalian toe bones (18.104.22.168.3), with closely related species still showing variable numbers.
26. Probelesodon (mid-Triassic; South America) -- Fenestra very large, still separate from eyesocket (with postorbital bar). Secondary palate longer, but still not complete. Teeth double-rooted, as in mammals. Nares separated. Second jaw joint stronger. Lumbar ribs totally lost; thoracic ribs more mammalian, vertebral connections very mammalian. Hip & femur more mammalian.
27. Probainognathus (mid-Triassic, 239-235 Ma, Argentina) -- Larger brain with various skull changes: pineal foramen ("third eye") closes, fusion of some skull plates. Cheekbone slender, low down on the side of the eye socket. Postorbital bar still there. Additional cusps on cheek teeth. Still two jaw joints. Still had cervical ribs & lumbar ribs, but they were very short. Reptilian "costal plates" on thoracic ribs mostly lost. Mammalian #toe bones.
28. Pachygenelus, Diarthrognathus (earliest Jurassic, 209 Ma) -- These are trithelodontids. Inflation of nasal cavity, establishment of Eustachian tubes between ear and pharynx, loss of postorbital bar. Alternate replacement of mostly single- rooted teeth. This group also began to develop double tooth roots -- in Pachygenelus the single root of the cheek teeth begins to split in two at the base. Pachygenelus also has mammalian tooth enamel, and mammalian tooth occlusion. Double jaw joint, with the second joint now a dentary-squamosal (instead of surangular), fully mammalian. Incipient dentary condyle. Reptilian jaw joint still present but functioning almost entirely in hearing; postdentary bones further reduced to tiny rod of bones in jaw near middle ear; probably could hear high frequencies now. More mammalian neck vertebrae for a flexible neck. Hip more mammalian, with a very mammalian iliac blade & femur. Highly mobile, mammalian-style shoulder. Probably had coupled locomotion & breathing.
29. Sinoconodon (early Jurassic, 208 Ma) -- The next known very ancient proto-mammal. Eyesocket fully mammalian now (closed medial wall). Hindbrain expanded. Permanent cheekteeth, like mammals, but the other teeth were still replaced several times. Mammalian jaw joint stronger, with large dentary condyle fitting into a distinct fossa on the squamosal. This final refinement of the joint automatically makes this animal a true "mammal". Reptilian jaw joint still present, though tiny.
Proto-mammal to Placental Mammal transition:
30. Kuehneotherium (early Jurassic, about 205 Ma) -- A slightly later proto-mammal, sometimes considered the first known pantothere (primitive placental-type mammal). Teeth and skull like a placental mammal. The three major cusps on the upper & lower molars were rotated to form interlocking shearing triangles as in the more advanced placental mammals & marsupials. Still has a double jaw joint, though.
31. Eozostrodon, Morganucodon, Haldanodon (early Jurassic, ~205 Ma) -- A group of early proto-mammals called "morganucodonts". The restructuring of the secondary palate and the floor of the braincase had continued, and was now very mammalian. Truly mammalian teeth: the cheek teeth were finally differentiated into simple premolars and more complex molars, and teeth were replaced only once. Triangular- cusped molars. Reversal of the previous trend toward reduced incisors, with lower incisors increasing to four. Tiny remnant of the reptilian jaw joint. Once thought to be ancestral to monotremes only, but now thought to be ancestral to all three groups of modern mammals -- monotremes, marsupials, and placentals.
32. Peramus (late Jurassic, about 155 Ma) -- A "eupantothere" (more advanced placental-type mammal). The closest known relative of the placentals & marsupials. Triconodont molar has with more defined cusps. This fossil is known only from teeth, but judging from closely related eupantotheres (e.g. Amphitherium) it had finally lost the reptilian jaw joint, attaing a fully mammalian three-boned middle ear with excellent high-frequency hearing. Has only 8 cheek teeth, less than other eupantotheres and close to the 7 of the first placental mammals. Also has a large talonid on its "tribosphenic" molars, almost as large as that of the first placentals -- the first development of grinding capability.
33. Endotherium (very latest Jurassic, 147 Ma) -- An advanced eupantothere. Fully tribosphenic molars with a well- developed talonid. Known only from one specimen. From Asia; recent fossil finds in Asia suggest that the tribosphenic molar evolved there.
34. Vincelestes neuquenianus (early Cretaceous, 135 Ma) -- A probably-placental mammal with some marsupial traits, known from some nice skulls. Placental-type braincase and coiled cochlea. Its intracranial arteries & veins ran in a composite monotreme/placental pattern derived from homologous extracranial vessels in the cynodonts. (Rougier et al., 1992)
35. Kennalestes and Asioryctes (late Cretaceous, Mongolia) -- Small, slender animals; eyesocket open behind; simple ring to support eardrum; primitive placental-type brain with large olfactory bulbs; basic primitive tribosphenic tooth pattern. Canine now double rooted. Still just a trace of a non-dentary bone, the coronoid, on the otherwise all-dentary jaw. "Could have given rise to nearly all subsequent placentals." says Carroll (1988).
Placental mammal to elephant transition:
36. Protungulatum (latest Cretaceous) -- Transitional between earliest placental mammals and the condylarths (primitive, small hoofed animals). These early, simple insectivore- like small mammals had one new development: their cheek teeth had grinding surfaces instead of simple, pointed cusps. They were the first mammal herbivores. All their other features are generalized and primitive -- simple plantigrade five-toed clawed feet, all teeth present (3:1:4:3) with no gaps, all limb bones present and unfused, pointy-faced, narrow small brain, eyesocket not closed.
37. Minchenella or a similar condylarth (late Paleocene) -- Known only from lower jaws. Has a distinctive broadened shelf on the third molar.
38. Phenacolophus (late Paleocene or early Eocene) -- An early embrithopod (very early, slightly elephant-like condylarths), thought to be the stem-group of all elephants.
39. Pilgrimella (early Eocene) -- An anthracobunid (early proto-elephant condylarth), with massive molar cusps aligned in two transverse ridges.
40. Unnamed species of proto-elephant (early Eocene) -- Discovered recently in Algeria. Had slightly enlarged upper incisors (the beginnings of tusks), and various tooth reductions. Still had "normal" molars instead of the strange multi-layered molars of modern elephants. Had the high forehead and pneumatized skull bones of later elephants, and was clearly a heavy-boned, slow animal. Only one meter tall.
41. Moeritherium, Numidotherium, Barytherium (early-mid Eocene) -- A group of three similar very early elephants. It is unclear which of the three came first. Pig-sized with stout legs, broad spreading feet and flat hooves. Elephantish face with the eye set far forward & a very deep jaw. Second incisors enlarged into short tusks, in upper and lower jaws; little first incisors still present; loss of some teeth. No trunk.
42. Paleomastodon, Phiomia (early Oligocene) -- The first "mastodonts", a medium-sized animals with a trunk, long lower jaws, and short upper and lower tusks. Lost first incisors and canines. Molars still have heavy rounded cusps, with enamel bands becoming irregular. Phiomia was up to eight feet tall.
43. Gomphotherium (early Miocene) -- Basically a large edition of Phiomia, with tooth enamel bands becoming very irregular. Two long rows cusps on teeth became cross- crests when worn down. Gave rise to several families of elephant- relatives that spread all over the world. From here on the elephant lineages are known to the species level.
44a. The mastodon lineage split off here, becoming more adapted to a forest browser niche, and going through Miomastodon (Miocene) and Pliomastodon (Pliocene), to Mastodon (or "Mammut", Pleistocene).
44b. Meanwhile, the elephant lineage became still larger, adapting to a savannah/steppe grazer niche:
45. Stegotetrabelodon (late Miocene) -- One of the first of the "true" elephants, but still had two long rows of cross-crests, functional premolars, and lower tusks. Other early Miocene genera show compression of the molar cusps into plates (a modern feature ), with exactly as many plates as there were cusps. Molars start erupting from front to back, actually moving forward in the jaw throughout life.
46. Primelephas (latest Miocene) -- Short lower jaw makes it look like an elephant now. Reduction & loss of premolars. Very numerous plates on the molars, now; we're now at the modern elephants' bizarre system of one enormous multi-layered molar being functional at a time, moving forward in the jaw.
47. Primelephas gomphotheroides (mid-Pliocene) -- A later species that split into three lineages, Loxodonta, Elephas, and Mammuthus:
The Pleistocene record for elephants is very good. In general, after the earliest forms of the three modern genera appeared, they show very smooth, continuous evolution with almost half of the speciation events preserved in fossils. For instance, Carroll (1988) says: "Within the genus Elephas, species demonstrate continuous change over a period of 4.5 million years. ...the elephants provide excellent evidence of significant morphological change within species, through species within genera, and through genera within a family...."
- Loxodonta adaurora (5 Ma). Gave rise to the modern African elephant Loxodonta africana about 3.5 Ma.
- Elephas ekorensis (5 Ma), an early Asian elephant with rather primitive molars, clearly derived directly from P. gomphotheroides. Led directly to:
- Elephas recki, which sent off one side branch, E. hydrusicus, at 3.8 Ma, and then continued changing on its own until it became E. iolensis.
- Elephas maximus, the modern Asian elephant, clearly derived from
- E. hysudricus. Strikingly similar to young E. hysudricus animals. Possibly a case of neoteny (in which "new" traits are simply juvenile features retained into adulthood).
- Mammuthus meridionalis, clearly derived from P. gomphotheroides. Spread around the northern hemisphere. In Europe, led to M. armeniacus/trogontherii, and then to M. primigenius. In North America, led to M. imperator and then M. columbi.
Species-species transitions among the elephants:
- Maglio (1973) studied Pleistocene elephants closely. Overall, Maglio showed that at least 7 of the 17 Quaternary elephant species arose through smooth anagenesis transitions from their ancestors. For example, he said that Elephas recki "can be traced through a progressive series of stages...These stages pass almost imperceptibly into each other....In the late Pleistocene a more progressive elephant appears which I retain as a distinct species, E. iolensis, only as a matter of convenience. Although as a group, material referred to E. iolensis is distinct from that of E. recki, some intermediate specimens are known, and E. iolensis seems to represent a very progressive, terminal stage in the E. recki specific lineage."
- Maglio also documented very smooth transitions between three Eurasian mammoth species: Mammuthus meridionalis --> M. armeniacus (or M. trogontherii) --> M. primigenius.
- Lister (1993) reanalyzed mammoth teeth and confirmed Maglio's scheme of gradual evolution in European mammoths, and found evidence for gradual transitions in the North American mammoths too.
Similar fossil sequences can be listed for the majority of other major-group transitions.
(Did I hear a creationist in the back row say something about "no transitional fossils?")
Note that the changes between any two sequential transitionals are small enough that most creationists would write them off as only "microevolution" -- and yet those 50-or-so "microevolutionary" steps turn a fish into an elephant, which even the most stubborn creationist would have to concede is "macroevolution".
Once you've answered the first question, here's a second one for you: If evolutionary common descent *hasn't* actually happened -- if the different animal "kinds" were just *poofed* into existence fully-formed -- then why is it possible to order known fossils into such a smooth "transitional" chain *at all*, in a way that makes sense and is chronologically, morphologically, genetically, paleontologically, geographically (etc. etc.) consistent with the (allegedly) "non-existent" evolutionary transitions? And no, it's not possible to assemble a sequence of fossils in just any damned order you want, so don't try *that* excuse -- even evolutionary biologists aren't capable of putting together a transitional fossil sequence "showing", say, a cat evolving into a bird, or a butterfly into a bat. Please explain.
(From Plagiarized Errors and Molecular Genetics)That's just a quick layman-level overview of *one* of the many ways that whale evolution has been verified. For more technical examinations along several independent lines of evidence, see for example:
A particularly impressive example of shared retroposons has recently been reported linking cetaceans (whales, dolphins and porpoises) to ruminants and hippopotamuses, and it is instructive to consider this example in some detail. Cetaceans are sea-living animals that bear important similarities to land-living mammals; in particular, the females have mammary glands and nurse their young. Scientists studying mammalian anatomy and physiology have demonstrated greatest similarities between cetaceans and the mammalian group known as artiodactyls (even-toed ungulates) including cows, sheep, camels and pigs. These observations have led to the evolutionist view that whales evolved from a four-legged artiodactyl ancestor that lived on land. Creationists have capitalized on the obvious differences between the familiar artiodactyls and whales, and have ridiculed the idea that whales could have had four-legged land-living ancestors. Creationists who claim that cetaceans did not arise from four-legged land mammals must ignore or somehow dismiss the fossil evidence of apparent whale ancestors looking exactly like one would predict for transitional species between land mammals and whales--with diminutive legs and with ear structures intermediate between those of modern artiodactyls and cetaceans (Nature 368:844,1994; Science 263: 210, 1994). (A discussion of fossil ancestral whale species with references may be found at http://www.talkorigins.org/faqs/faq-transitional/part2b.html#ceta) Creationists must also ignore or dismiss the evidence showing the great similarity between cetacean and artiodactyl gene sequences (Molecular Biology & Evolution 11:357, 1994; ibid 13: 954, 1996; Gatesy et al, Systematic Biology 48:6, 1999).
Recently retroposon evidence has solidified the evolutionary relationship between whales and artiodactyls. Shimamura et al. (Nature 388:666, 1997; Mol Biol Evol 16: 1046, 1999; see also Lum et al., Mol Biol Evol 17:1417, 2000; Nikaido and Okada, Mamm Genome 11:1123, 2000) studied SINE sequences that are highly reduplicated in the DNA of all cetacean species examined. These SINES were also found to be present in the DNA of ruminants (including cows and sheep) but not in DNA of camels and pigs or more distantly related mammals such as horse, elephant, cat, human or kangaroo. These SINES apparently originated in a specific branch of ancestral artiodactyls after this branch diverged from camels, pigs and other mammals, but before the divergence of the lines leading to modern cetaceans, hippopotamus and ruminants. (See Figure 5.) In support of this scenario, Shimamura et al. identified two specific insertions of these SINES in whale DNA (insertions B and C in Figure 5) and showed that in DNA of hippopotamus, cow and sheep these same two sites contained the SINES; but in camel and pig DNA the same sites were "empty" of insertions. More recently, hippopotamus has been identified as the closest living terrestrial relative of cetaceans since hippos and whales share retroposon insertions (illustrated by D and E in Figure 5) that are not found in any other artiodactyls (Nikaido et al, PNAS 96:10261, 1999). The close hippo-whale relationship is consistent with previously reported sequence similarity comparisons (Gatesy, Mol Biol Evol 14:537, 1997) and with recent fossil finds (Gingerich et al., Science 293:2239, 2001; Thewissen et al., Nature 413:277, 2001) that resolve earlier paleontological conflicts with the close whale-hippo relationship. (Some readers have wondered: if ruminants are more closely related to whales than to pigs and camels, why are ruminants anatomically more similar to pigs and camels than they are to whales? Apparently this results from the fact that ruminants, pigs and camels changed relatively little since their last common ancestor, while the cetacean lineage changed dramatically in adapting to an aquatic lifestyle, thereby obliterating many of the features -- like hooves, fur and hind legs -- that are shared between its close ruminant relatives and the more distantly related pigs and camels. This scenario illustrates the fact that the rapid evolutionary development of adaptations to a new niche can occur through key functional mutations, leaving the bulk of the DNA relatively unchanged. The particularly close relationship between whales and hippos is consistent with several shared adaptations to aquatic life, including use of underwater vocalizations for communication and the absence of hair and sebaceous glands.) Thus, retroposon evidence strongly supports the derivation of whales from a common ancestor of hippopotamus and ruminants, consistent with the evolutionary interpretation of fossils and overall DNA sequence similarities. Indeed, the logic of the evidence from shared SINEs is so powerful that SINEs may be the best available characters for deducing species relatedness (Shedlock and Okada, Bioessays 22:148, 2000), even if they are not perfect (Myamoto, Curr. Biology 9:R816, 1999).
Figure 5. Specific SINE insertions can act as "tracers" that illuminate phylogenetic relationships. This figure summarizes some of the data on SINEs found in living artiodactyls and shows how the shared insertions can be interpreted in relation to evolutionary branching. A specific SINE insertion event ("A" in the Figure) apparently occurred in a primitive common ancestor of pigs, ruminants, hippopotamus and cetaceans, since this insertion is present in these modern descendants of that common ancestor; but it is absent in camels, which split off from the other species before this SINE inserted. More recent insertions B and C are present only in ruminants, hippopotamus and cetaceans. Insertions D and E are shared only by hippopotamus and cetaceans, thereby identifying hippopotamus as the closest living relative of cetaceans (at least among the species examined in these studies). SINE insertions F and G occurred in the ruminant lineage after it diverged from the other species; and insertions H and I occurred after divergence of the cetacean lineage.
The first thing I found is that there's a reason why creationists really ought to break their habit of learning their "science" from a) creationist sites or b) press releases (and why evolutionists more often than not read the primary literature, which is something I've almost never seen a creationist doing).
The press release did indeed say that "because since the reign of the dinosaurs, about 100 million years ago, army ants in essence have not changed a bit". But this is just the reporter's piss-poor misunderstanding (and therefore misrepresentation) of what the study *actually* determined. Nowhere in the study itself is there any hint of a claim that army ants "haven't changed a bit" in the past 100 million years.
What it *does* say is:
The army ant syndrome of behavioral and reproductive traits (obligate collective foraging, nomadism, and highly specialized queens) has allowed these organisms to become the premiere social hunters of the tropics [...] Results strongly indicate that the suite of behavioral and reproductive adaptations found in army ants throughout the world is inherited from a unique common ancestor [...] Because no known army ant species lacks any component of the army ant syndrome, this group represents an extraordinary case of long-term evolutionary stasis in these adaptations.In other words, the three *characteristics* which make an army ant what it is (1. foraging in groups -- most non-army ants use scouts, 2. nomadic lifestyle -- most non-army ants nest in one place, 3. flightless queens which can pump out *millions* of eggs) came into being 100 million years ago and have persisted ever since. Needless to say, that's quite a different thing than the much more general "army ants haven't changed a bit" claim the reporter made.
Nor is the press release's headline accurate or supported by the study ("Army ants, as voracious as ever, have defied evolution for 100 million years, Cornell entomologist finds ").
There's nothing in the study about "defying evolution". The only thing I could find which the reporter might have (very badly) mistaken for such a claim is where the author points out that previous *assumptions* (which were recognized to be no more than assumptions) were that "old world" and "new world" army ants may have evolved separately from non-army ancestors on their respective continents. Instead, this study finds, there was a single army-ant ancestor and all modern army ant families/species descended from them. So the results of this study "defy" previous presumptions about how army ants may have evolved, but hardly "defy" evolution itself.
Someone shoot that reporter...
Meanwhile, the study's findings are interesting in their own right, and add yet more data to the massive mountains of hard evidence *for* evolution (which insulting cartoons by our resident creationists do nothing to refute).
Using a variety of measures (DNA base-pair sequences consisting of three nuclear and one mitochondrial gene totalling 3538 basepairs from each of the 49 extant ant species, fossil evidence, and 116 morphological metrics), the author's mathematical analysis produced a cladistic tree for both army ants and many non-army ant species as follows:
The letters (A-H) indicate points in time where the subsequent "branches" are known to have already existed, because representatives from each "branch" have been disocovered in the fossil record.
The branches marked with "*" are branches where the ML tree analysis produced results with "a posterior probability of >95% after independent Bayesian phylogenetic analysis".
As described in the press release, this does indeed clearly indicate that all modern army ants (species shown in bold type) descended from a common ancestor, instead of from two or more common ancestors which were themselves not army ants.
It's also interesting to note that all the "old world" (OW) and "new world" (NW) army ants are separate branches of the oldest split of the army ant family tree. This demonstrates that, as previously presumed, the lifestyle of the army ant (especially, wingless queens) precludes any cross-continental "crossovers", where some species had (during the last 100 million years) managed to travel from one continent to another and take up new residence there.
This correct presumption -- along with the incorrect presumption that army ants had appeared more recently than 100 million years ago -- was the basis for the original assumption that old-world and new-world army ants had perhaps evolved independently (on their respective continents).
Instead, this DNA and morphological analysis (which, by the way, does *not* depend on a "genetic clock") strongly indicates that army ants first arose approximately 105 million years ago.
The reason that this is such an interesting result is that it *very* closely matches the known time of existence of the Cretaceous super-continent of Gondwana, *and* the time of the old-world/new-world army ant split matches the known time of the break-up of that supercontinent into separate continents which contain what is now South America (on one side) and Africa (on the other), the respective homes of the new-world and old-world army ants.
In other words, the analysis strongly matches an evolutionary model in many different ways, including several I haven't even mentioned here.
First, the fact that such a "family tree" works out *at all* is strong evidence that evolution has actually taken place. If instead ants of various species and/or "kinds" had been separately created, there's no reason at all that their DNA details *and* their fossil traces *and* their morphological details would so neatly fit a timewise evolutionary tree of common descent *at all*. For just one example, if the species at the top of the tree and the bottom of the tree shared a characteristic gene sequence, while the other species didn't (because, say, God felt they each would benefit from it), then the entire tree structure would be blatantly violated. Instead, every time DNA/morphological data is analyzed in this way, even across widely divergent species like cows and giraffes and whales, an implied "tree of common descent" is inarguably implied by the evidence.
Second, in this case, the "family tree" implied by the evidence "just happens" to *exactly* match geologic events which would be expected to explain parts of the tree if it came about via evolution. For example, if all modern army ants had a common ancestor, then at some point in time the ancestral army ant must have arisen at a particular geographic location (obviously). This would be a problem if, for example, the data implied that this happened at a time before ants existed at all, or after army ants were known to exist in fossils, etc. And yet, when the available evidence is objectively analyzed by a mathematical algorithm with no ideological ax to grind, the results beautifully match an evolutionary origin consistent with the known fossil record, timewise.
Furthermore, red flags would be raised if the time-and-place of the calculated origin happened to fall in a place where army ants would be highly unlikely to have gotten from their point of origin to the separate continents where they are seen today (e.g. South America and Africa). But lo and behold, the analysis shows the time-and-place of the calculated origin to be at a time when those two continents were known to be joined.
Furthermore, the calculated split between old-world and new-world army ants is found to fall at a time when the continents themselves split apart, perfectly explaining how and why the populations on each new continent, now isolated, should (and thus did) diverge into families of species which evolved in unrelated directions from each other (thus forming species that, while all still army ants in lifestyle, show characteristic differences).
And so on and so on.
Again and again, every time studies and analyses like this -- and every other conceivable type -- are performed, the results "just happen" to fall in a way that makes perfect sense if modern (and fossil) life had arisen from earlier life forms in a common-descent, evolutionary process, like individual jigsaw puzzle pieces all of which form a smooth, coherent picture (albeit with some pieces still not yet discovered) where all the pieces found so far all mesh smoothly with their neighbors.
If evolution is *not* true, why does the jigsaw puzzle formed by the mountains of evidence so well match the evolutionary picture predicted by the theory? How many more would you like to see?
Evolution is a False "God".
See, you're confused again. Evolution is not a "God" at all, it's science, and is supported by ovewhelming amounts of evidence.
Really, step away from the creationist propaganda and try reading some actual *science* for a change... You have a vast amount of misinformation in your head that can be cured by actual facts, if you just open your eyes and go looking. Little do you know how little you know.
One might say that each society is a mosaic of pieces uniquely arranged to achieve the same final landscape: prosperity. To the extent that the arrangement doesn't produce that outcome, then the pieces are eventually rearranged. Some become obsolete; others may be discovered. Many are interchangeable.
At least that's how I see it!
One additional thing I should note is that I actually haven't given that much thought to the contrast in religious intensity between the United States and Europe. It's a topic that's crossed my mind once in a while but not one I've seriously pondered. Generally what interests me are the grand patterns of history, not the trivial permutations. As I see it, in the grand scheme of things it's of no great consequence if the United States in this regard arrives at the same juncture a few decades later than does Europe. What is of consequence is that they both appear to be headed toward the same destination.
Anyhow, what I'm getting at is that I have no great stake in my above conjecture about the distinction between America and Europe. I could very well be wrong (in my primary attribution of it to geopolitics). That's what strikes me as most plausible, but I am quite open to alternative explanations. The statement that "the well springs of American religiosity run much deeper than that" doesn't help much, because it seems to me the whole sub-question we're examining is: Why? It's not as if the well springs of European religiosity were exactly barren not so long ago..
Finally, look at the ruins of Yugoslavia. Even after 45 years of secular harmony they didn't have any problem finding religious intensity once it again suited their political aims. Ireland is another example: is their political conflict due to religious intensity, or is their religious intensity due to the political conflict? I would submit far more so the latter (and this extends back to their oppression by the English).
I'm not on anybody's side.
I provide information. Not everyone is at the same knowledge level on every subject and I find discussions go better when the participants have enough information to be on a par with one another.
In addition, because of the pervasive poor quality of teaching the basic sciences, many people think they know a good deal that is actually incorrect. It is not their fault if they trusted their teachers and it should not be used against them to score debate type points.
When i asked, poliitely, for a retraction of a demonstrable and demonstrated falsehood, and it was met with a rant, I should have ended the conversation there. My mistake. I won't compound it further.
Mine is signed by Heinlein, but, of course, you can't "see" it, nor could you trust a scanned image.
Are you sure you exist? ;-)
I was lookiing for a prefix that specifically meant right-wing, but Germans seem to simply say right-. But I admit my alternative doesn't work either.
Please note for the official record my successful capture (prior post) of the only primAL number.
Mere primes, pah!
Spider web structures and silks began their co-evolution [sic] about 400 million years ago [sic], at first probably as a protein cover to protect the animals eggs and young. Webs then evolved different functions [sic], including acting as a kind of wall-paper for the animals burrow and modifying the hole into a simple trap by radiating lines that inform the lurking spider about things beetling around outside. Even such simple lines expand the animal�s anatomical phenotype many fold by incorporating the body into an extensive silken net. The aerial webs of the modern [sic] spiders began to evolve [sic] perhaps 200 million years ago [sic] and are superb examples of extended anatomy. These webs also nicely illustrate the close interaction of material and behaviour which clearly are two separately encoded yet functionally inter-linked character traits.This seems to say that they evolved because they evolved.
This is a prime example of the leaps of faith rampant among Darwinians, who can discuss with apparent wonder the technologies of the animal kingdom capabilities that dwarf human efforts based on intelligent engineering then say they just evolved, with utter, implicit, and complete faith in the inspired Word of Charlie, who alone does wonders. Then they have the audacity to accuse non-Darwinians of relying on faith instead of science.
Vollrath apparently was not at all aware of nor troubled by the fact that he dodged the question about evolution. How did the spider web evolve? It evolved, he said. Any skill or technology needed was available to the spider with the snap of the evolutionary fingers. Example: certain spiders have evolved to produce web fibres that have an aqueous coating, supplied and maintained by hygroscopic compounds to attract the required water molecules from the atmosphere. How did the spider find these hygroscopic compounds and incorporate them into the production line? It evolved.
That explanation is all-sufficient. The precise acidity control? It evolved. The hyperbolic extrusion die? It evolved. The exact recipe of proteins, sugars, phosphates, calcium, sulfur, neurotransmitter peptides and other organic and inorganic ingredients that yielded a substance humans cannot emulate? It evolved. The ability to control the solidification and folding at exactly the right time and place? It evolved. The ability to sort out tough silks and soft, flexible sticky silks into a radial pattern? It evolved. The skill to snare insects, detect their presence, and get to them without getting stuck itself? It evolved.
It evolved because it evolved: that is apparently enough intellectual content to satisfy a brainwashed Darwinist. Some humans build webs, too; the tangled kind, spun by self-deception. Watch from a safe distance.
From Creation-Evolution Headlines
Which lies are those?
How about a few hundred for starters? Here's a *small* sampling of creationist dishonesty (again from a prior post of mine):
And I'm not talking about random anonymous statements on fly-by-night websites.
Summary of the ability of two creationists (Hovind and Havoc) to present information they *know* is false, and to *fail* to retract when reminded of their falsehoods, is presented here, along with links to all appropriate documentation.
This sort of behavior, unfortunately, is *typical* of creationists. Here, want dozens of more examples of their distortions? A few more for the road? Another? Still more, perhaps? How about even more? Ooh, here are some good examples. And there's lots more where that came from, like this and this and this and lots more here and *tons* here and countless more here and yet more here, a goodie... Wait, there's more over here, etc., etc., etc., etc., etc., *ETC.*, etc., etc., etc., . How about 300 more creationist misrepresentations? Not enough, you say? Well then visit Creationist Lies and Blunders.
Neither am I. I'm talking about dishonest statements from leading "lights" of the creationist movement such as Henry Morris, Duane Gish, Kent Hovind, Ken Ham, Steven Austin, Carl Baugh, Jonathan Sarfati, Michael Behe, Jonathan Wells, William Dembski, Don Patton, Steve Rudd, Phillip Johnson... the list is endless.
I'm talking about published evolution critics like Johnson, Behe, Dembski, etc.
So are we.
[Out of context quotes are lies.]
No published author in the ID movement has quoted Dawkins out of context.
Many well-known creationists have, repeatedly. Henry Morris, for one example of many. If you want to split hairs and try to hand-wave that away by declaring that he doesn't meet your narrow definition of "the ID movement", then all I can say is that I hear bagpipes.
But your real sleight-of-hand is attempting to divert attention from the original issue (which was, and I quote, "the lies told by creationists" and how that's one of the reasons that Dawkins (and others) express "venom" at the antics of the creationists), to your own change-the-subject version of "published authors in the ID movement who have quoted Dawkins out of context". The evasion is obvious.
They have pointed out where his stated views conflict with some of his observations.
No, many creationists have grossly misrepresented Dawkins's writings by taking them grossly out of context. Deal with it.
But since you seem to think that Behe, Johnson, Dembski, et al are somehow without sin in this regard, let's check out an egregious example of lying-via-misleading-quotation from Dembski, shall we?
I can't possibly describe the depths of Dembski's dishonesty better than Jason Rosenhouse of EvolutionBlog has already done, so I'll just let you read his excellent article on Dembski's brazen deceit:
I wholeheartedly concur.Monday, May 02, 2005
A Study in ID Duplicity
UPDATE: May 3, 2005: In the original version of this post I consistently misspelled Dave Mullenix's last name. I have now corrected that error. I have also corrected various other typos and stylistic infelicities.
On April 26, William Dembski posted this brief essay at his blog. He was responding to the charge that ID proponents, himself included, routinely quote scientists out of context in order to distort their intended meaning. Since I have levelled that charge myself, I was curious to see how Dembski would reply. The blog entry begins as follows:
Unlike the serious sciences (e.g., quantum electrodynamics, which is accurate up to 14 decimal places), evolution has become an exercise in filling holes by digging others. Fortunately, the cognitive dissonance associated with this exercise cant be suppressed indefinitely, so occasionally evolutionists fess-up that some gaping hole really is there and cant be filled simply by digging another hole. Such admissions, of course, provide ready material for evolution critics like me. Indeed, its one of the few pleasures in this business sticking it to the evolutionists when they make some particularly egregious admission.
Tough talk! From here the essay went on to discuss a particular instance of alleged ID quote-mining. The quotation in question was taken from paleontologist Peter Ward. We will come to the details in a moment, but first the relevant links:
Dembski first invoked the quote in this essay (PDF format).
He was called on it by Gary Hurd and Dave Mullenix in this essay posted at The Panda's Thumb.
Now, as it happens, prior to preparing this blog entry I had not read Dembski's essay (entitled Five Questions Darwinists Would Rather Dodge). I also had not read Hurd and Mullenix's response. And while we're at it, let me mention that I had never heard of Peter Ward and had not read his book.
So I was able to enter into this with no preconceived notions. I knew that by simply gathering the relevant documents I could see for myself whether it was Dembski, or his critics, who were telling me the straight story.
I began with Dembski's original essay. Dembski was making the case that evolutionists would prefer to dodge the question of whether the fossil record provides strong evidence for evolution. The relevant passage is the following:
The challenge that here confronts evolution is not isolated but pervasive, and
comes up most flagrantly in whats called the Cambrian Explosion. In a very brief
window of time during the geological period known as the Cambrian, virtually all
the basic animal types appeared suddenly in the fossil record with no trace of
evolutionary ancestors. The Cambrian Explosion so flies in the face of evolution
that paleontologist Peter Ward wrote, If ever there was evidence suggesting
Divine Creation, surely the Precambrian and Cambrian transition, known from
numerous localities across the face of the earth, is it. Note that Ward is not a creationist.
Already a question emerges. The quoted sentence from Ward gives the impression that he believes the Cambrian explosion to be srong evidence for Divine Creation. If that is an accurate description of what Ward believes, then why isn't he a creationist?
But no matter. Dembski clearly believes that the Cambrian explosion provides a fundamental challenge to evolution. He is asking us to believe that Peter Ward concurs with that assessment, even if Ward does not agree with Dembski's antievolutionary conclusions.
The next step seemed clear. The Ward quote came from his 1992 book On Methuselah's Trail. One thing I love about working at a university is that I can count on the library to have books like Ward's. I took a walk over to the library, and five minutes later walked out with the book.
I flipped to page 29 and found that Ward had indeed written the words attributed to him by Dembski. They come at the beginning of a section entitled The Base of the Cambrian. In this section Ward gives a brief history of what is known about the Precambrian to Cambrian transition.
So I decided to read the rest of the section. After the quote Dembski cited, Ward goes on to describe Darwin's own concerns about the Cambrian explosion (though that term did not exist in Darwin's time). He also discusses various explanations offered by some of Darwin's contemporaries, such as Roger Murchison and Adam Sedgwick, and shows how those explanations fared in the face of subsequent discoveries.
This discussion goes on for several pages. Eventually Ward comes to more modern views of the subject. And this, sadly, is where it becomes clear that Dembski blatantly misrepresented Ward's views of the subject.
On page 35 Ward writes this:
Until almost 1950 the absence of metazoan fossils older than Cambrian age continued to puzzle evolutionists and earth historians alike. Other than the remains of single-celled creatures and the matlike stromatolites, it did indeed look as if larger creatures had arisen with a swiftness that made a mockery of Darwin's theory of evolution. This notion was finally put to rest, however, by the discovery of the Ediacarian and Vendian fossil faunas of latest Precambrian age.
And on page 36 we find:
Intensive searching of strata immediately underlying the well-known basal Cambrian deposits in the years between 1950 and 1980 showed that the larger skeletonized fossils (such as the trilobites and brachipods) that supposedly appeared so suddenly were in fact preceded by skeletonized forms so small as to be easily overlooked by the pioneering geologists.
And just in case there is still any doubt, Ward closes the section with the following statement:
The long-acepted theory of the sudden appearance of skeletal metazoans at the base of the Cambrian was incorrect: the basal Cambrian boundary marked only the first apearance of relatively large skeleton-bearing forms, such as the brachipods and trilobites, rather than the first appearance of skeletonized metazoans. Darwin would have been satisfied. The fossil record bore out his conviction that the trilobites and brachipods appeared only after a long period of evolution of ancestral forms. (pages 36-37)
These quotes make it obvious that Ward does not believe the Cambrain explosion poses any problem for evolution. Indeed, the final statement show that Ward views recent discoveries about the Precambrian to Cambrian transition to be a vindication for Darwin.
Seen in context, the statement quoted by Dembski, about the Cambrian explosion being evidence for Divine Creation, was not a statement about what Ward or any modern scientist believes. Rather, it was a statement about how things seemed at the time Darwin entered the scene.
So it's clear that Dembski misrepresented Ward. Dembski used Ward's statement to imply that even evolutionary biologists admit that the Cambrian explosion is a big problem, when in reality Ward's view is exactly the opposite. Nonetheless, I forged ahead.
The next step was to read what Hurd and Mullenix had to say on the subject.
They began with a lengthy discussion in which they showed that Dembski's statements about the Cambrian explosion, quoted above, are quite false.
They next discuss the Ward quote, and came to the same conclusion I did. They even used two of the same quotes that I found.
Hurd and Mullenix then go on to point out that after distorting Ward's statement, Dembski goes on to distort a statement from Stephen Jay Gould. Hurd and Mullenix defended these assertions with copious evidence. I invite you to follow the link I provided and see for yourself what they wrote.
Let's review. Dembski tried to imply that the non-creationist Peter Ward nonetheless agrees with Dembski's view that the Cambrian explosion is a problem for evolution. In reality, Ward's clearly stated view is that while the Cambrian explosion used to be viewed as a problem for evolution, recent fossil discoveries actually show that it is a vindication for Darwin. Hurd and Mullenix pointed this out, showing in great detail that Dembski had not only distorted Ward, but had done likewise to Gould. They also show that Dembski's version of the facts is simply wrong.
And that brings us back to Dembski's blog entry. How would he respond to these facts? We resume the action from the point where my opening quote left off:
Consider the following admission by Peter Ward (Ward is a well-known expert on ammonite fossils and does not favor a ID-based view):
The seemingly sudden appearance of skeletonized life has been one of the most perplexing puzzles of the fossil record. How is it that animals as complex as trilobites and brachiopods could spring forth so suddenly, completely formed, without a trace of their ancestors in the underlying strata? If ever there was evidence suggesting Divine Creation, surely the Precambrian and Cambrian transition, known from numerous localities across the face of the earth, is it.
Peter Douglas Ward, On Methuselahs Trail: Living Fossils and the Great Extinctions (New York: W. H. Freeman, 1992), 29.
Pretty convincing indicator that the Cambrian explosion poses a challenge to conventional evolutionary theory, wouldnt you say? Note that this is not a misquote: I indicate clearly that Ward does not support ID and theres sufficient unedited material here to make clear that he really is saying that the Cambrian explosion poses a challenge to conventional evolutionary theory.
Unlike in his original essay, Dembski now gives the entire paragraph from which the Divine Creation statement appeared. He then asserts that this clearly indicates that the Cambrian explosion poses a challenge to conventional evolutionary theory. As we have seen, it does not. In context, it is clear that Ward was simply setting up the ensuing discussion.
Dembski then asserts that this is not a misquote on the grounds that (a) he indicates clearly that Ward does not support ID and (b) he includes enough material here to show Ward's true intention.
We have already shown that (b) is false. This paragraph by itself does not give an accurate presentation of Ward's views. In fact, Dembski uses it to imply the opposite of Ward's opinion.
And (a) is totally irrelevant. At issue is not whether Ward is a creationist or an evolutionist. The question here is what he thinks of the Cambrian explosion.
Incidentally, Dembski's original essay asserts only that Ward is not a creationist. He made no mention of ID at that time. This suggests that Dembski, despite his frequent public statements to the contrary, does not really believe there is any important difference between ID and creationism.
Moving on, we return to Dembski:
Youd think, therefore, that the evolutionary community might be grateful to evolution critics for drawing their attention to this problem, treating it as an incentive to get the lead out and figure out just what happened during the Cambrian. But thats not what happens. Rather, evolution critics are charged with quote mining, misrepresenting the true state of evolutionary theory by focusing on a few scattered problems rather than toeing the party line and admitting that evolution is overwhelmingly confirmed.
What nerve! Peter Ward devotes close to ten pages of his book to explaining what happened during the Cambrian explosion, as revealed through fossil discoveries over the last hundred years. He concludes this discussion with the unambiguous statement that Darwin has been vindicated. He opens the discussion with a rhetorical flourish to make the problem seem utterly insurmountable, so as to make the ultimate solution seem all the more dramatic.
Dembski presents the flourish as if it represents Ward's view on the subject. He then ignores Ward's discussion in its entirety and accuses evolutionists of being uninterested in finding out what happened during the Cambrian.
He even gets the little things wrong. People like Dembski do indeed misrperesent the state of evolutionary science, but that is not what the charge of quote-mining is about. Quote-mining has to do with misrepresenting the views of specific scientists, not the state of evolutionary theory generally.
Furthermore, the issue is not that ID folks focus on a few scattered problems. It is that the things they identify as problems for evolution, such as the Cambrian explosion, are, in reality, not problems.
Moving on, we find that in a footnote to their essay, Hurd and Mullinex point out that they contacted Peter Ward for comment on Dembski's misuse of his words. Here's Dembski's response:
And, as is now standard operating procedure, the original author of the quote is contacted for comment on being quote-mined. Predictably, the author (in this case Ward) is shocked and dismayed at being quoted by evolution critics for being critical of evolution. Evolutionists may not know much about what actually happened in the course of natural history, but they have this script down:
We [i.e., Gary Hurd et al.] emailed and then telephoned Peter Ward to ask him for a citation to this quote. He actually couldnt recall where he had written this. Ultimately we had to ask William Dembski for the citation, which he promptly provided. We would like to thank him publicly for this courtesy. Professor Ward was not at all pleased, and wished us to convey to Dr. Dembski his displeasure at his writing being manipulated in this fashion. We consider this as done herein.
Word of advice: if you are an evolutionist and dont want to be quoted by evolution critics for being critical of evolution, resist the urge dont criticize it. If tempted, even if the reality of evolutions gaping holes is staring you in the face, close your eyes and repeat the phrase overwhelming evidence or nothing in biology makes sense apart from evolution.
As we have already pointed out, Ward was not being critical of evolution. Quite the contrary.
The facts here are perfectly unambiguous. Dembski twisted Ward's words to make them appear to mean exactly the opposite of Ward's clearly stated intention. When that was pointed out to him he responded with further distortions and tons of arrogance.
The next time you read someone whining about the strong rhetoric from people on my side of this issue, think about this case. Then think about whether maybe it's perfectly reasonable to refer to the major proponents of ID as frauds and liars.
Thank you for bringing my attention to this article. I may use it sometime in the next few months as part of an exhibit clarifying how accidental features may form the basis for new evolutionary pathways and open up new ecological niches (the space _between_ grass blades).
Example: certain spiders have evolved to produce web fibres that have an aqueous coating, supplied and maintained by hygroscopic compounds to attract the required water molecules from the atmosphere.
Yes, it evolved. Many polyanions and polycations - DNA, for one - are hygroscopic. Take a silk fiber and change a few amino acids to give them a charge and you've made it more hygroscopic. Point mutation followed by natural selection = evolution. Or co-extrude one of any number of hygroscopic carbohydrate polymers, which arachnids make in quantity.
How did the spider find these hygroscopic compounds and incorporate them into the production line? It evolved.
The spider found nothing. The spiders that expressed a gene that made their webs attract water survived better. One wonders why anyone has difficulty with the idea.
That explanation is all-sufficient. The precise acidity control? It evolved. The hyperbolic extrusion die? It evolved. The exact recipe of proteins, sugars, phosphates, calcium, sulfur, neurotransmitter peptides and other organic and inorganic ingredients that yielded a substance humans cannot emulate? It evolved. The ability to control the solidification and folding at exactly the right time and place? It evolved. The ability to sort out tough silks and soft, flexible sticky silks into a radial pattern? It evolved. The skill to snare insects, detect their presence, and get to them without getting stuck itself? It evolved.
Why does he have a problem with any of this?
It evolved because it evolved: that is apparently enough intellectual content to satisfy a brainwashed Darwinist.
On the contrary, all of these processes were characerized by people who had enough intellectual curiosity to go discover and study them, then to have their curiosity denied by some jerk with time on his hands and a penchant for multicolored fonts. And what's his beef? Because in contrast with the complexity of the mechanisms themselves, biology has a comparatively simple explanation for their ontology - evolution. It's not that he dislikes the simplicity per se, either; he prefers another equally simple but far less useful explanation - Godidit.
Just one of the limited number of standard Creationist arguments. Compile a lengthy litany of biological facts - chances are, all of them discovered by Darwinian biologists - and then point to them and ask, how could something that complex have evolved? Argumentum ad ignorantem.
Ah, the skirl of the pipes through the morning mists in the glen, as the haggis fries in the pan. No true Scotsman would lack a tear in his eye and a lump in his throat when he hears it!
In contrast, many IDers come from a very different background. Johnson is a lawyer, where the style of argumentation is almost exactly opposite - you find a few small apparent inconsistencies in a large body of evidence, and work them to death, ignoring what the overall body of the evidence shows. Dembski is a philosopher by training - philosophers work by trying to find inconsistent consequences of a premise, and if a premise leads to a contradiction, they've won. Even those IDers who are biologists usually have little research experience. Behe's an exception, and I think most of us find Behe the least offensive of them. though it appears he's starting to pick up bad habits.
So thence the quote mining. Scientists start by presenting the case against their own argument. Anti-evolutionists see this as an opportunity, grabbing that part of he argument, stripping off the context or any indication why it was being presented, and say 'aha!'.
Haggisdidit place mark
"Important" is a rather subjective term.
Very interesting. I was guessing, based on the timing of both developments, and of course I got it wrong. But it's amazing that it was done without photography. (It's not amazing that I made a wrong guess.)
One of the listed features of the fundamentalist mindset in a psychology paper my wife recently brought to my attention, is the inability to see the world in anything but "either-or" terms -- either you bend to will of Allah, or you die. Either you take Genesis literally, or you are not a Christian.
Believe it or not, there are a lot of shades in there, too.
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