Darwin vs. 'Darwin' - if you can't beat 'em, caricaturize 'em!
` ATTN: In the process of adding rest of illustrations.
[Image of Darwin, Image of Caricature of Darwin]
` At long last, after more than three weeks I have completed (writing) this post - and fought the temptation of writing any others during bouts of writer's block! Though it is a fine essay for anyone to read, it also addresses my fellow biology students.
` Science, as I've written before, isn't an overly natural process to human beings: When we have an idea, it's our first instinct to come up with evidence to support it. In science, not only do you learn as much as you can, you try to find evidence that disproves your ideas. (That way you know if you got something wrong.)
` Darwin's Theory of Evolution Through Natural Selection has passed, with flying colors, a century or more worth of tests that were designed to disprove it. (Some people don't agree, and I'm getting to that.)
` Charles Darwin was a creationist who began to explore the natural world - it wasn't until after his travels that he became convinced that natural processes and long stretches of time could account for all the variations seen throughout life on earth.
` Today, so much is known about biological processes that evolution has long been considered a fact. Even Darwin, in the mid-1800s, could not explain anything that he knew - about comparative anatomy, populations, biogeography, embryology, paleontology, etc. - without referring to the idea that all species living today had a common ancestor.
` The question he asked was how did it happen?
` Darwin's version of 'how' is called the Theory of Evolution Through Natural Selection, whereby certain organisms are 'edited out' by their own environment. It is true that one organism can produce many more than one replacement for itself. As a result, this creates many 'chances' for its lineage to continue - and there surely needs to be.
` The million-dollar question is; which offspring will survive?
` Despite what opponents of evolution will say, Darwin's theory is far from being completely random: Mutations and new variations abound - especially with species that reproduce sexually - so not all offspring are equal. Many even have extra copies of genes, missing genes, mutated genes, or simply unusual combinations of genes, all of which can affect their ability to survive. Over the generations, 'disadvantaged' individuals will be completely 'bred out' of a population while better-adapted are likely to be preserved, or 'selected' by nature.
` Thus, species are forced to change into others. And, as the environment also changes, what was useful for one individual may make survival difficult for its great-grandchildren. So, species continue to be forced into changing. But, if enough individuals of a species cannot do this, their kind faces the ultimate cut - extinction.
` The Theory of Evolution is not to be confused with the general concept of evolution, which simply refers to the fact that species are constantly changing. This is important because it may be helpful to know that anti-evolutionists confuse them all the time.
` About Darwin: He wasn't the first to come up with a theory of how evolution happened, but his is the only one for which all of biology - as well as chemistry, geology, cosmology, et cetera, have done nothing but back it up.
` This is why it's called the Grand Synthesis - pretty much everything we know about the universe relates to and supports Darwin's theory in some way.
` The Theory of Evolution Through Natural Selection is truly a gargantuan concept - so huge that it is based on a lot of different laws of nature as well as statistical probabilities. Since a law can only contain one very simple and utterly absolute concept - such as the speed of light, or the law of gravity - Darwin's theory encompasses far too much to ever become a law.
` Similarly, a lot of the patterns and activity of your cells is also based on both laws and statistics - and are thus not always consistent or predictable - and yet, their tendencies still manage to form a living, changing body that doesn't suddenly lose coherence. There is no 'Law of a Human Body', and there never could be.
` There is a lot of ignorance on the subject of evolution in this country (and thus plenty of misconceptions) so it's relatively easy to get many people to swallow a false picture of Darwin's theory - one that makes evolution look nonsensical - whether or not they agree on its validity.
` This is what Intelligent Design proponents do (as did the 'Creation Science' proponents before them). Intelligent Design Theory - which (as you'll see) is merely an attack on Darwin rather than an actual theory - was employed by creationists as a 'Wedge', explicitly to gain converts.
` Main ID proponent and lawyer, Phillip Johnson, describes how he came up with the idea ('Berkeley's Radical', Touchstone Magazine, 2002):
So the question is: "How to win?" That’s when I began to develop what you now see full-fledged in the "wedge" strategy: "Stick with the most important thing" —the mechanism and the building up of information. Get the Bible and the Book of Genesis out of the debate because you do not want to raise the so-called Bible-science dichotomy.` This explains why the book Of Pandas and People, which goes on about design and a designer, was originally called Creation and Biology and talked about God and the book of Genesis.
Phrase the argument in such a way that you can get it heard in the secular academy and in a way that tends to unify the religious dissenters. That means concentrating on, "Do you need a Creator to do the creating, or can nature do it on its own?" and refusing to get sidetracked onto other issues, which people are always trying to do.
` Another main ID proponent, William Dembski, explains the motivation behind it (National Religious Broadcasters convention, 2000):
Intelligent Design opens the whole possibility of us being created in the image of a benevolent God … The job of apologetics is to clear the ground, to clear obstacles that prevent people from coming to the knowledge of Christ … And if there’s anything that I think has blocked the growth of Christ as the free reign of the Spirit and people accepting the Scripture and Jesus Christ, it is the Darwinian naturalistic view.` Phillip Johnson also highlights his reasoning (Missionary Man, Church and State Magazine 1999):
The objective is to convince people that Darwinism is inherently atheistic, thus shifting the debate from creationism vs. evolution to the existence of God vs. the non-existence of God. From there people are introduced to ‘the truth’ of the Bible and then ‘the question of sin’ and finally ‘introduced to Jesus.’` There you have it - in their own words, not mine: Intelligent Design theory is missionary work disguised as some sort of 'scientific' debate. Some have told me, "it doesn't matter where the science comes from; science is science and it's wrong to censor it."
` And I say, "What science?" The ID camp is taking their firm belief in a creator and distorting the methods, logic and fruits of science to make evolution look bad, rather than using them to support what they're saying (which they claim is what they are doing).
` As even they have openly admitted, while they have a few ideas that supposedly attack evolution, there really isn't an actual theory to 'ID Theory' since just saying "that ain't so" does not explain "how, then?" There's no rhyme, rule or mechanism proposed - according to them, life could have been (nondescriptly) designed at one point, or gradually created over millions of years, depending on the particular aspect or scale of evolution that is being skewed at the time.
` As I will demonstrate (in time), they are basically making up a bizarre version of evolution that doesn't make sense - this is then presented as the real thing. A general poor understanding of evolution is what actually 'makes their case' - most scientists (of any type) are not fooled by this ploy.
` Theory or not, ID proponents are not deterred because in their attacking of 'pseudo-evolution' they apparently believe they can just say; "since evolution makes no sense, that means we're right anyway!" Gee, that's bad news for anyone who comes up with an alternative explanation to Darwin's theory - ID is apparently already right!
` A combination of this, the 'false dichotomy', along with the 'argument from ignorance' is another important long-time creationist/ID tactic. What they do is argue that "there's no evidence for X, which means X doesn't exist; therefore evolution just doesn't make sense, so we must be right."
` Intelligent Design proponents argue this way in the name of science and sound logical reasoning - though it is precisely the opposite; Any scientist (or logician) can tell you, a lack of information just means that nobody knows - therefore, there is no information telling them that there's evidence against evolution.
` It just so happens that the thousands of 'Xs' that have later been found - including DNA and everything about it - that do support evolution. Even so, anti-evolutionists have maintained that some such discoveries actually weaken the existing evidence for evolutionary theory.
` My favorite is what they do with transitional species. Here's one example: Since Darwin's time, biologists have theorized that the ancestors of whales once lived on land.
[Image of Darwin, inset]
` Why? For one thing, whales are mammals, which (as it is now even more clear from the numerous reptile-mammal fossils) evolved from land reptiles. For another thing, embryonic whales have pelvises, hind legs and toes, as do adult whales (albeit usually on the inside): I myself have had the pleasure of seeing a dolphin skeleton and a gray whale skeleton, both with these vestigial appendages intact. (In some individuals, these structures develop into visible flippers.)
` Presumably, the first highly aquatic whales were like today's otters, sea lions, or walruses, which gradually adopted a more marine lifestyle. (Could seals be the next 'whales'?)
` Then one day, paleontologists dug up part of a land mammal's skull whose highly unusual ear canal and teeth resembled that of no other known species except for living and fossil whales. This species, a carnivorous ungulate (hoofed mammal), was dubbed 'Pakicetus' or 'whale from Pakistan'.
` Since then, many more bones have been found, allowing for more accurate reconstructions:
[Pakicetus skeleton, skull and reconstruction]
` Though it doesn't look like a typical cetacean (whale), Pakicetus is classified as one because it shares the most important defining characteristic - the distinct ear canal.
` The anti-evolutionists still scoffed at the land-whale, a common claim being that; "There's no evidence of any transitional species between Pakicetus and whales (one instance of evolution), so we still must be right about God creating everything (all instances of evolution)."
` No transitional species at all? A very presumptuous argument, yes, and one that's been well-demonstrated to the contrary. Indeed, there has since been discovered many species which bridged Pakicetus with ancient whales.
` These specimens were found in the right chronological order, in the time period before modern-looking whales are found - they span from about fifty-seven to thirty-six million years ago:
[Images of fossil species, including Ambulocetus, Dalanistes, Rodhocetus, Takracetus, Gaviocetus, Durodon, Basilisaurus.]
` So, though this is more information for biologists, this also happens to make many antievolutionists cheer, because instead of one 'gap' in the fossil record, we now have many gaps to criticize! ("But what about the transitional species between Takracetus and Gaviocetus?")
` On the other hand, other antievolutionists instead ignore most or all of the transitional species and baselessly criticize any that they do acknowledge.
` Pure logical fallacies aside, as I've said, the most prominent 'arguments' comprising Intelligent Design 'theory' is the complete distortion of entire evolutionary concepts and/or facts. ID proponents and their followers are protected by a general ignorance that the arguments are distortions - even they themselves may not know.
` So, let me use an overly obvious example of the type of distortion I mean: Let's say someone is telling you about the characteristics of mammals - i.e. lungs, mammary glands, a high metabolism, a large cerebrum, three middle ear bones - and then points out that whales have them, too. Well, of course they do; they're mammals.
` Then the person points out that whales swim up-and-down like mammals do, and not side-to-side like fish, and that everything we know about whales tells us that whales are mammals, not fish. Well, is that supposed to be surprising? There's nothing wrong with these statements.
` But then - now that he's got you agreeing with him - this person concludes that the very fact that whales are mammals means that the evolution of whales is impossible. (And then goes off on a rant about how 'brainless' scientists are to have missed that.)
` Ask yourself, does that argument make any sense at all (much less warrant any anger)? Whales are mammals - that's a fact. I've just highlighted their evolution from other mammals. Could this argument possibly make any sense?
` Only in the light of a false picture: This person claimed that scientists believe whales evolved directly from fish, without leaving the ocean, so how could we have two separately-evolved groups of animals that by 'random coincidence' are both unmistakably mammals? (Especially since it doesn't make any sense for a fish to get rid of its ability to breathe water!)
` Well, I will admit one thing; this idea is contrary to all available evidence....
` I'd like to point out that this isn't in particular an Intelligent Design argument, though someone really did use that to try to outsmart me and my 'dogmatic faith' in evolution. While my facial expression in response showed I was amazed with at how far removed from reality it was, he took this to mean that he had brought up an excellent point.
` Nevertheless, this is exactly the type of thing found in ID arguments: Describe one thing accurately (such as facts about whales) and then describe another thing inaccurately (such as the premise of those facts) in such a way that it creates contradictions.
` Obviously, changing select facets of something that is logically consistent - so that it becomes otherwise - allows the possibility of convincing people that it is the real article, and therefore that the real article is worthy of ridicule.
` There you have it, that's the main 'scientific' debate technique involved in ID theory - if both the real bits and the distorted bits are accepted as an equally valid whole, then it certainly would appear that evolution is falling apart at the seams.
` But how many people know enough or care enough not to swallow at least many of the false concepts as facts? If public opinion polls mean anything, probably not a large proportion.
` To reiterate, Intelligent Design is all about creating the illusion of attacking evolutionary theory (as well as science in general). Proponents are merely pretending that a dysfunctional caricature is evolutionary theory and work to persuade people to laugh at it - as if scientists would be short-sighted enough to support such a thing!
` I guess you could say, the scientists might laugh as well, but for a different reason.
` I tried explaining this once to a friend who supported ID at the time, and she assured me; "Oh no, I haven't heard any arguments like that! This is all solid science." Sure enough, everything about evolution she proceeded to criticize was nothing but laughter directed at whimsical caricatures of evolutionary theory.
` What's more, she had no clue she was doing this.
` Every time I started to explain how each argument was not attacking real evolutionary theory or findings, she just changed the subject and came back to it later as if I hadn't attempted to scrutinize it in the first place. This quickly became exhausting.
` It was like a hopeless game of Whack-A-Mole; she had a handful of arguments, and she kept cycling through them as fast as I could lunge at them. She never gave me the chance to actually point something out. (On top of that, she used the argument of 'you're really in for it because you don't believe in God'.)
` It was somewhat dismaying to me that she really thought she got me good every time I was shocked by an argument akin to 'whales aren't fish': Many a time I had to suppress the urge to rebuke her for believing in the caricature drawn by Intelligent Design proponents.
` If they drew the tooth fairy, I had thought to myself, she would believe in that, too.
` So, I might as well get around to some of these arguments, right? Why not pick one on a topic that concerns something that's extremely important to know about Darwin's theory? Here goes:
` Some ID arguments come from the distortion (pushed as real evolutionary theory) that species evolved in a linear fashion in an order somewhat like a scala naturae, with minerals at the bottom and complex beings - humans - at the top. We've come a long way since then, as you can see....
[Scala naturae]
` Darwin's theory has never included the idea of a scala naturae because all the evidence supports a spreading family tree, with one species branching into two. In this way, though chimpanzees have smaller brains than we do, they are not more 'primitive': We share a common ancestor which lived at least six million years ago.
` Whatever this species was (Sahelanthropus? Orrorin?), it must have split into two or more subspecies (something that we see happening today) where one population gave rise to an upright ape lineage while the other became a tree-climbing ape lineage.
` Interestingly, DNA evidence shows that the common ancestors of gorillas and orangutans existed farther back in time than our common ancestor with chimps. In other words, chimpanzees are more closely related to us than they are to gorillas or orangutans.
[Human & Ape family Tree]
` I've heard a few people scoff, "I'm sorry, evolution just doesn't make any sense: No one can explain to me why, if humans evolved from monkeys, can there still be monkeys."
` If the 'ladder' of species made sense, that might be a tough one to get out of, but as you can see, there's nothing contradictory about the idea that humans evolved from "monkeys", or rather, apes that lived millions of years ago. Modern humans, monkeys and apes can all live at the same time - though the ancestors that once linked us necessarily had to live in the past.
` There is one website I know of that is dedicated to compiling an accurate family tree with data from various different scientists. It's called the Tree of Life Project, if you're interested.
` So, what this means is that today's fish are not 'stuck in the past', in any concrete way. They are actually very highly-evolved versions of primitive fish that lived millions of years ago. And, so are we - after one of those primitive fish scooted, mudskipper-like, onto land. So, in a way, we are fish - it's just a difficult concept for us to wrap our highly-developed brains around.
` In other words, ever since the common ancestor of all fish lived, all of its descendants have been evolving for the same amount of time as one another.
` Why don't we resemble primitive fish as much as the hundreds of species of fish living today do? Because they haven't had to adapt to living on land - so they continue to have similar body structures.
` We also have the same basic structures, but they have been re-shaped for life on land. For one thing, lungs must have gone from being mere swim-bladders to oxygen-absorbing organs in our common ancestor with lungfish. But, while a lungfish's lungs are adapted to store oxygen when they need it, we are adapted for breathing on land, 24/7.
` They are, therefore, two (of many) different possible modifications of the same organ. In fact, every part of a fish can - effectively - be found in your own body (though it may not be easily recognized). This type of correspondence is called a homology, and I'll point a bunch more out by the time I'm through.
` Now, finally approaching a specific ID argument, let me tell you a bit about genetics: The DNA of, say, a monkey, a whale, and a frog, have the same amount of genetic changes relative to their last common ancestor. However, if you compare a monkey's genes with a whale's and a frog's, the whale is the one that's going to be more similar to the monkey because they have a more recent common ancestor.
` As one evolutionary biologist remarked (Gould, I believe), evolution acts like a 'short-order cook', not a long-term planner. It adapts a species for its immediate situation with what it already has at the time - through history, one part is used over and over again for different purposes.
` This is what creates homologies.
` Characteristics can even evolve and then 'evolve away', which explains the presence of vestigial parts (such as whale's hind legs - or a snake's) that clearly had some past purpose (walking) but no longer do.
` There's no way that Nature could 'know' what would happen if fish evolved into land animals. They just happened to be going somewhere that no vertebrate had gone before, perhaps at first to chase their crunchy prey (like a modern species of African catfish does with its leg-like fins and bendable neck), or to escape from predators (as flying fish do by gliding on their enormous fins).
` Species must survive in the 'here and now' - they cannot 'rest' or 'wait' because they'd go extinct. This, along with the 'life is a huge family tree concept', are fundamental to Darwin's theory.
` So, you're not more 'evolved' than your cousin, you're just on different branches. The whole idea of progress in evolution, like an arrow of complexity from bacteria to humans, is completely against the Theory of Evolution Through Natural Selection.
` Well, guess what Intelligent Design theorists often insist? And since that's wrong, then evolution must be wrong. But that's not part of Darwin's theory! And so, at long last....
` As I've said, genetic studies do support evolution, however, this can be turned on its head if you don't understand what's going on: In the 1980's, Michael Denton said that protein differences between species don't support evolution. (Since proteins are straightforwardly direct expressions of genes, this could be considered an argument from genetics.)
` He studied a protein that has to do with cellular metabolism, called cytochrome C, which is common to all life. Between organisms, however, there are variations. As with teeth, nerve cells and blood, the chemistry of life is homologous across species.
` After measuring the amount of differences (divergence) across many species' versions of cytochrome C, he wrote:
"Between horse and dog (two mammals) the divergence [in cytochrome C] is six percent, between horse and turtle (two vertebrates) the divergence is eleven percent, and between horse and fruit fly (two animals) the divergence is twenty-two percent." (Denton 1985.)` Well, that's perfectly consistent with evolution. See? (You'll have to click on the picture to see, because my blog is too narrow to display it any larger.)
` And yet, Denton said that in all his studies, since he couldn't find any proteins from a transitional species in anything alive today, it must mean that Darwin is wrong. And Darwin would point out that transitional species of modern animals - and their proteins - lived millions of years ago.
` Here's my own version of the Venn diagram made from Denton's cytochrome C analysis. Notice how everything is in overlapping groups, exactly as they are in the Linnean classification heirarchy.
` He said that these data made evolutionary theory "collapse" because the modern animals' proteins did not show any signs that they evolved into proteins in another animal living at the same time. Well, why would evolutionary theory predict that?
` What it does predict is that such protein findings will fit right in with the family tree of animal life - and they do:
` And yet, according to Denton, bacteria ought to be at the bottom. Bottom of what? Eukaryotes and prokaryotes have been separate for something like two billion years - that constitutes four billion years of changes because we count both branches since the common ancestor.
` So, one can see four billion years of changes between bacteria and pigeons, four billion years of changes for bacteria and yeast - you get the idea. There's the same amount of changes between modern prokaryotes and modern eukaryotes.
` As you can see here, Denton has also found this:
` So, the four billion years between bacteria and all these eukaryotes has resulted in about the same number of differences in cytochrome C. Unsurprisingly, that supports evolutionary theory absolutely, but no; Denton said that Darwin's theory dictates that bacteria ought to show more signs of being primitive, that they should be relatively close to wheat, and a little farther from silkworms, and father than that from tuna.
` Here's the part where we say, "Oh no, whales aren't fish, so Darwin was wrong!"
` (Interestingly, Denton has since retracted these arguments - and has admonished others to follow suit - because he's realized that they don't make any sense.)
` Another Intelligent Design argument - and this is a major one - is about where bacterial flagella come from. One of the major Intelligent Design 'theorists', Michael Behe, says that they simply couldn't, and that's it. Therefore, evolution is impossible. (And by default, ID 'theory' is right.)
` I could mention that he also said that transitional fossils between land animals and whales was impossible, too....
` Behe claims that components for various body parts can't just one day appear in the right order, just as a tornado can't assemble a Boeing 747. Well, I don't think they can either, but what does that have to do with evolutionary theory?
` That's the inaccurate premise right there - and unsurprisingly, it doesn't fit with the facts.
` He says the all the parts of the bacterial flagellum must be present for the entire thing to work; there is no way that it could be functional if it's missing a part, and any of the parts cannot work by themselves. As this is firmly not the case in reality, the argument's already been proven wrong.
` But, since he chooses to ignore this fact, he will still tell you that bacterial flagella cannot be reduced and therefore have 'irreducible complexity'; their existence is only possible if a creator put all the parts together 'just so'.
` My own brashness aside, let us look at this argument from another angle: It is like saying that birds' wings simply cannot exist unless a creator 'put them on', fully-formed, because forelimbs (arms) and feathers cannot exist by themselves.
` So, this is our analogy:
[Armless, naked bird compared to modern bird]
` Actually, this is similar to what they have said about birds - except that instead of having no arms, they had tiny arms because coelurosaurs (the family of dinosaurs birds are in) apparently all had tiny arms like Tyrannosaurus.
` Actually, Tyrannosaurus is an unusual coelurosaur because it had small arms - Therizinosaurs, Oviraptors, Troodontids and Dromaeosaurs are more typical. The Dromaeosaurs - the ones most similar to birds - are called 'knuckle draggers' by the people who dig them up because their arms and hands are frequently longer than their legs and feet.
` We find the same feature with primitive birds (and most modern birds). In fact, Dromeosaurs (think Velociraptor) have more characteristics in common with primitive birds than modern birds do.
[Bird skeleton compared to dromaeosaur and crow skeletons]
` Though the fossil record at the very beginning of the bird family tree is sketchy, it is reasonable to assume that dromaeosaurs shared a close common ancestor with them. (This runs counter to the anti-evolutionist claim that Velociraptors couldn't have evolved into primitive birds because they lived after the first birds did.)
` But I digress. My point is that birds got their present characteristics from their ancestors. So, where did their wings come from, ultimately? Glad you asked: Fish have the same bones in their fins as we have in our arms and legs - they are homologous, just variations on a theme.
` Tiktaalik was a fish that had functional wrists in its fins, as well as a bendable neck - adaptations also seen in the African catfish that runs out of the water. After this species lived similar fish that had fin-like legs, so it seems to have something to do with them.
` Since then, though land vertebrates have lost several of these arm bones, the remaining ones are still homologous in all species. Therefore, legs evolved from fish fins.
[My illustration of this is pending....]
` Where did birds get their feathers? Well, if you change the genes of chickens, a type of scale they have - called a scute - turns into a feather. Dinosaurs had scutes, too, and so do crocodiles.
` You might be amused to know that I learned this while critiquing an article in Creation magazine that had a note inserted saying that 'reptillian' scales have less in common with feathers than previously thought, and this fact was discovered by a great biologist named Alan Brush - 'so there, evolution is wrong and God created everything'.
` So, I looked the article up and found that what Brush had actually discovered was that the molecular makeup of feathers are almost the same as those of scutes as well as other scales found on birds, including their beak coverings. Also, the genes involved in making scutes are the same as the ones for feathers (homologous structures come from homologous genes).
` On the other hand, 'reptillian' scales, which both lizards and birds have, were less similar in these respects.
` As the misleading article said, feathers aren't that similar to 'reptillian' scales - and this is because they came from another type of scale! Coelurosaurs certainly had feathers - though most of them had what would be called 'protofeathers', which are feathers that lack the microscopic structures to hold the fibers together.
` But, you have the basic equipment. The first birds - like the famous Archeopteryx - were basically mini-Velociraptors, retractile foot-claws and all.
` It's not like evolutionary biologists speculated that a tornado happened and suddenly the animal had feathers and wings and could fly. I believe the scientific term for that is 'magic'. Instead, they speculate that the animals already had something similar to wings and began climbing trees and/or leaping on prey, leading them onto a path that left the ground.
` Back to the flagellum argument: So Michael Behe says that a bacterial flagellum is so complex it could not have just been thrown together as, he claims, biologists think. Since that is not what biologists really think, so how is this an argument? Who does he think he's attacking?
[Caricature of Darwin]
` Not Darwin!
` Anti-evolutionists have said the same thing about eyes - what's the use of half an eye? If you look at something that actually has 'half an eye', like a flatworm, or a scollop, or even a single-celled organism, you would observe that very simple vision as opposed to complete blindness can be a matter of life and death.
[Eyes of all types]
` Each type of eye could realistically have descended from a less complex type that is similar to those in today's species - even the photosensitive cell itself: Though such cells detect light through a very long line of complex chemical reactions (something that ID proponents mention), these are almost identical to homologous pathways in other cells (which they carefully don't mention).
` Just as scientists are always learning new things about how eyes evolved, they are also learning about Behe's bacterial flagellum. For one thing, there are other, simpler types of flagella out there - 'half a flagellum' so to speak - which he curiously ignores.
` This overturns the idea that flagella are irreducibly complex; the reduced versions function perfectly fine, though they are used for different jobs. What biologists think really happened is that the flagellum Behe is talking about was put together from from these other molecular mechanisms, not by randomly clumping proteins together and accidentally making something useful.
` Now, back to birds for a minute; as I've mentioned several times, different parts and systems can evolve for one reason and then wind up being adapted for a different function later on.
` Birds once had grasping fingers, but modern birds' hands fuse into wingtips before they are born. Interestingly, the bizarre hoatzin's wings develop later than those of other birds, so it has useful opposable digits which turn into wingtips by the time it needs to fly from the nest.
` Speaking of baby birds, they are born with downy plumage - the most 'primitive' form of feather - before developing more complex 'adult' feathers. Partly for this reason, scientists think that dinosaurs had down before other types of feathers evolved.
` But what good is down? Keeping warm. Dinosaurs - as suggested by everything known about them to date - grew fast, moved fast and had high metabolisms. Especially the bird-like dinosaurs. So, it would appear that they were able to regulate their body temperatures internally.
` So, certain dinosaurs once needed 'wing' components to trap body heat and to grasp things. They had another purpose other than flight. It also turns out that each part of Behe's bacterial flagellum is homologous to other assemblies of proteins.
` A lot of them are actually found in pilins, which are structures used for exchanging genetic material between cells. The base of Behe's flagellum is homologous to at least ten proteins found in the Type III secretory apparatus, which is used for attaching to other cells and pumping chemicals into them (as found on plague bacteria).
` These 'reduced' flagellum parts are completely functional doing a different job - they don't need to be assembled 'just so' with all the other parts of Behe's example flagellum to be acted on by natural selection.
` How is Behe's complex (but not irreducibly complex) flagellum powered? Did the rotary motor just appear, like Behe says it must have for "evolution" to occur, or did it come from something else?
` Speaking to my fellow students; does anyone remember ATP synthase? It uses the energy from ions to produce a rotary motion. That very enzyme is the part. The 'irreducible' part.
` In fact, four different assemblages found in Behe's flagellum are found doing other things in other parts of cells. And, against what Behe says, cilia are also functional when disassembled.
` Well, who ever said, just because a part is being used in a particular structure, that this was its original purpose? Not this guy.
[Darwin]
` Maybe it was this other guy....
[Caricature of Darwin]
` To deny and change simple facts about biology, including the nature of evolutionary theory itself, is to create the illusion that it isn't in working order. That's what Intelligent Design Theory really is, because when you remove these distortions, ID ceases to exist.
` If it's not science, then why would anyone come up with ID 'Theory'? Instead of being put forward as an idea that could have some value for scientists, it was created to 'introduce' students to 'Jesus', as I've already shown.
` For these reasons ID proponents have been the ones working hard to sell rhetoric, not Darwin.
5 comments:
Sequine..
Gosh, your strict rules really freak me out!!!
Besides, your post was not easy reading. And where was the caricature of Darwin?...G
Hi, how's it going? I love how you explain things so clearly. I'm going to link to this. It's damning to hear the ID/creation/missionary people condemned out of their own mouths.
` I am a stickler for order, G-man - without 'Order', Linnaeus would have had a hole in his taxonomic hierarchy! O_o
` (Um, yeah.... I'm mentally exhausted from typing posts in an online college discussion board assignment about ID vs. evolution.)
` I'm sorry you had a tough time reading this - my added illustrations might help.
` Sometime between studying for/practicing for/putting together my finals and taking care of basic personal hygiene, I'll have to update it to run a little more smoothly. (I was up until four in the morning last night!)
` My caricature of Darwin was supposed to be done yesterday, but can you believe I had something more important to draw?
` He'll be the next illustration to go up.
` Monado, glad you could follow what I was writing without any illustrations - then again, this is kind of your area! ;)
` And, though the ID proponents have condemned themselves by explaining their motives, this fact is still lost on many people.
` *Note to self: Place more emphasis on that in update.*
` Well, I must go run a very important movie-making errand - buying props for a scene being shot tomorrow.
Oh, I like the pictures. For Darwin and caricatures, check Wikemedia Commons: Charles Darwin. They should all be out of copyright since they were drawn, published, or taken more than a hundred years ago.
I also found an early caricature: young Darwin riding on a beetle and a modern, but not unkind, caricature of Darwin.
` Thanks! I was planning on doing a middle-aged Charles Darwin.
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