[Rusty] the Cambrian Explosion, [DarkSyde] DS~There's plenty of reason why we see more metazoan fossil remnants in certain Cambrian Strata. Not the least of which is that there is one, and only one, fairly large Cambrian strata holding huge numbers of fossils so exquisitely preserved that we even get soft tissue. The Burgess Shale. There are several smaller areas in less rich biomes from around the same time, but nothing like the Burgess. It helps to actually have the proper sediments, exposed, of the time period in question. It also helps to have critters with hard endoskeletons and hard shells. There was also apparently a large and severe series of Glaciations that occurred just prior to the Cambrian which would have limited the habitable areas of the Earth-remember all life was at this time almost exclusively underwater and dependent ultimately on cyano-bacteria. That glaciation seems to have ended right before the Cambrian Explosion. And when I say extreme, I mean perhaps all the way to the equator. There is more and more evidence for this scenario called "The Snow Ball Earth Theory", and it's quite fascinating...the mechanism for reversing the glaciation is ingenious and I leave it to the interested reader to learn what it was. Hint: It's something the BushCo admin wants to deny exists.Saying we have no clue what the heck happened, throwing your arms in the air and claming it must have been magic, is very much an argument from ignorance. I agree. But that’s not what I’ve done. I’ve written a bit on the Cambrian Explosion here, and anyone who wishes to study it will find out that the more we learn about the event, the more we realize how profound it was. Further research has shown that the explosion of body plans occurred in less than five million years. Note that the evolutionary paradigm posits that further research will show that the “explosion” actually took longer than what the evidence currently says. Yet continued research into both large Cambrian strata locations (i.e., Canada and China) demonstrates that the opposite is true. I am aware of the Snowball Earth theory and agree that it is a fascinating read (ref. Rare Earth by Brownlee & Ward). I also agree that the methods involved are ingenious which, by the way, is an adjective modifying a process of a mind. I’m not quite sure why Dark raises the issue of the glacial period just prior to the Cambrian. The evidence at this time certainly points to the Cambrian Explosion occurring as soon as optimally possible. From the viewpoint I present, it fits in with the notion of a purposeful plan. Please check my posts on how the presence of a plan indicates design at these posts: post1, post2, post3, post4. That there is evidence of life forms prior to the Cambrian Explosion is not the issue of concern with regards to the event. What is the issue are the variety of complex body plans that appear in a geologic instant. By Dark’s own description, the types of life forms we see prior to the explosion are immensely different from those that appear during the explosion. The question continues to be, how did the diversity and complexity appear so suddenly? I agree with Dark that the event continues to be enigmatic, and I also agree that it is an exciting field for further study… let’s see where the data from continued research will point us. For further reference: The Cambrian Explosion Biology's Big Bang (PDF), by Stephen C. Meyer, Marcus Ross, Paul Nelson and Paul Chien
The "explosion" took place over about 10-20 million, and that's just that we know of! Twenty-million years takes you from tiny mouse sized mammals to Hyeno-dons and Indricotheriums. Some of the largest animals who ever live. It takes you from small birds to 600 pound Androgorlinis Terror birds. It's about the same or more than the length of time it took for whales to evolve from artiodactyls. We now have many many fossils of Precambrian critters. That period preceding the Cambrian is called the Edicarian (Or Vendian for you diehards) and we have a smattering of fossil creatures, fossil burrows, sponges, from well before the Cambrian, etc. We also have an enormous number of cyno-bacteria communities preceding the Cambrian by BILLIONS of years. We have chemical signatures for widespread life going back 4 billion years. We would not expect to find jellyfish, simple annelids, or other gelatinous creatures, very often if ever. They wouldn't have much chance of fossilizing even under ideal conditions. Nevertheless the exact series of events which may have produced a large radiation of novel lifeforms just before the Cambrian has not been resolved and remains an exciting and fruitful field of investigation. Saying we have no clue what the heck happened, throwing your arms in the air and claming it must have been magic, is very much an argument from ignorance.
[Rusty] molecular motors, [DarkSyde] DS~If you saw a real electron micrograph of a eu-bacterial flagella, it would not look like the nice little symmetrical gizmo Dembski uses in his presentation! It would look like a collage of weird blobs. But in anycase, so what? Don't stop with bacteria, we Humans have not only molecular 'motors' (our muscle tissue for example), we have molecular cameras, molecular 'combat' troops, molecular microphones and molecular speakers.The issue isn’t whether an actual bacterial flagella looks like the clean animations we see presented to us. It also doesn’t matter whether the graphics are presented by an ID proponent like Bill Dembski or within a secular Biochemistry textbook like this. What matters is whether the structural makeup of the flagellum is analogous to a rotary motor. Not only is it analogous, it is a direct analog! The parts are given their various names, mimicking human artifact counterparts, precisely because of their corresponding function. Check my post On Plans, templates, and similarities… for additional comments. Unfortunately, appealing to possible co-opting in conjunction with forever lost intermediate forms is hardly a slam-dunk apologetic for evolution. Once the molecular structures are unpacked from the use of evolutionary lensing and unwarranted extrapolations, we’re left with irreducibly complex structures. In his review of Bill Dembski’s book No Free Lunch, H. Allen Orr overconfidently claims that the so-called irreducibly complex structures Michael Behe writes about are accessible through Darwinian evolution. Bill Dembski has written a devastating response to Orr’s review which can be found here. The exact details of how and why those various structures evolved is something we're likely to never know in absolute full detail. C’mon Dark, that sounds like an argument from ignorance or, at least, circular reasoning (e.g., “well, we know they evolved… we just don’t know how.”).
. Life is made of molecules. The exact details of how and why those various structures evolved is something we're likely to never know in absolute full detail. We can see what the selective advantage would be in most cases, in a few cases we have extant creatures showing what appear to be earlier, or perhaps rudimentary, forms of those structures. And we have fossil showing some of the larger types of structure which appear to be in the process of being co=opted for a secondary use. But we'll probably never know the precise series in each generation that selected for the precursors of those structures on a molecular, or the precise change in the base pairs which produced them, ever. It would be like saying that if you can't trace the exact footsteps of the Romans who cut down the tree and what kind of ax they used, and the exact tools carpenters who fashioned the cross used, and the exact each step that Jesus walked carrying that cross, then none of it ever happened, it's all conjecture and myth.
[Rusty] convergent evolution, [DarkSyde] DS~I'll need an example, here but I can broadly say that similar parameters of a biome might produce similar superficial form and furthermore than NS would predict it. One would expect this if natural selection has any say about the matter. You expect that creatures who fly would have something like wings which catches air. The classic example being ichthyosaurs, sharks, penguins, and cetaceans. They torpedo shaped, and I wonder why that would possibly beI don’t have time to go into the topic of convergent evolution at present. Suffice it to say that there is not a consensus among evolutionists on this topic. The late Stephen J. Gould is oft-quoted as stating that if one were to rewind the tape of history on planet earth, and let events play out again, that we’d end up with a much different world than the one we have. Also, it should be noted that there are examples of convergent evolution in which dissimilar environmental parameters were involved, as well as examples of similar environmental parameters with differing morphological structures. One can read up on it at this link. Notice the evolutionary lensing that is occurring here. We hear statements to the effect of, “notice how well adapted evolution has made the shark.” When queried as to how we know that evolution did it, the response is along the lines of, “well they’re here, aren’t they?” Don’t you see the circular reasoning here, let alone how the design explanation is willfully ignored?
? Even octopi assume a smooth streamlined profile when trying to haul ass. You wouldn't expect a free swimming sea creature to resemble an open parachute if the idea was to move quickly!
[Rusty] speciation rates, etc.). [DarkSyde] Not sure what you mean here. We've observed speciation both in the lab and in the wild. So it goes without saying we know it can happen. We also have many examples of related taxa which can produce fully interfertile offspring, infertile offspring, and in some case where there is normally no offspring but occasionally a hybrid can be produced. See ZONKEY . Evolution/diversifiation explains this. It explains why brown bear and polar bears can still reproduce with each other. It explains why tigers and lions can reproduce but only very rarely produce fertile ligers or tigons. It explains why burros and zebras can reproduce. How does IDC explain it?I’ve stated above that speciation has not been observed. We'll just have to leave it that we disagree on this. What I am referring to by speciation rates is that the average rate of speciation, as indicated by the fossil record, falls woefully short of what we currently observe. Add to that the fact that species will go extinct, regardless of human intervention, and the question arises as to just where are all these new species that we should be seeing?
[Rusty] This is not an argument from ignorance. [DarkSyde] It most certainly is, with a bit of denial and misinformation used to spice it up. It's classic DI or Hugh Ross material.No comment.
[Rusty] It is precisely because of how much we've learned that we know how intractable the problems are. [DarkSyde] Intractable means to me 'can never be solved.' But in your usage, solved to what degree? We can resolve that birds evolved from reptiles or that humans evolved from earlier primates in a number of independent ways. We can't yet, and we may never, resolve on a step by step, individual generation to individual generation why some of it happened. Does Intelligent design and manufacture lay contingent on evolution being false? Or is perhaps your personal religious convictions that rely on evolution being invalid, and IDC could simply be a method of creation used by the Creator just as He used stellar-nucelosynthesis? What is the Scientific Theory of Intelligent Design? Is it compatible with evolutionary biology? What evidence would you accept for evolution, or against antievolution?There once was a time when chemists thought they could turn lead into gold. They don’t think that way anymore. I doubt any chemist could get funding for a renewed attempt at alchemy. Note that it isn’t because of ignorance that we know we can’t turn lead into gold, but because of knowledge. Some evolutionists like to paint ID proponents as enemies of science with no inclination for continued research. But let’s take a look at what Guillermo Gonzalez and Jay Richards have to say in their recent book, The Privileged Planet:
We live in a universe with laws and initial conditions finely tuned for the existence of complex life. Although narrowly constrained, they do not inevitably give rise to such life. They are necessary but not nearly sufficient for it. In extremely rare pockets of that universe, conditions are congenial to the existence of beings who can observe the starry heavens above and ponder the meaning of their existence. In at least one of these places, despite struggle and adversity, some came to believe that the world around them was a rational, orderly universe, accessible not only to rational thought but also to careful investigation. Centuries of study, amplified by technological tools and innovation, have given rise to an unparalleled knowledge of the world around us. The combination of those preliminary discoveries now gives rise to another: The same rare conditions that have sustained our existence also make possible a stunning array of discoveries about the universe. There is a purposeful value in this. Because of it, and only because of it, can our aspirations for scientific knowledge and discovery be satisfied. Careful investigation, study, and observation of the natural world ultimately succeed. With enough persistence, the natural world discloses itself to us in ways that we do not, and sometimes cannot, anticipate. Once perceived, the thought creeps up quietly but insistently: The universe, whatever else it is, is designed for discovery. What better mandate could there be for the scientific pursuit of truth? Scientific discovery enjoys a sort of cosmic prestige, but a prestige apparent only to those open to the possibility that the cosmos exists for a purpose. (emphasis in original)Whether or not my personal religious convictions apply here is not the issue. Everyone has personal convictions. Any implication that those people with religious convictions are incapable of objectively analyzing empirical data is not only without merit, but it is itself a personal conviction. The question comparing naturalistic evolution with that of stellar formation and whether or not God uses both is a good one. Although the answer delves into the merits and logical implications of methodological naturalism, with which I’ve addressed here, we should also understand the differences between the two. Stellar formation is not dependent on natural selection. Given the same set of parameters, we should see the same results. Granted, the more complex the situation (e.g., the formation of an Earth-like planet within a solar system like our own), the more complex the parameters. But the processes involved are essentially dependent on the laws of physics. With naturalistic evolution the situation is essentially dependent on chance. That is, given the same set of parameters, the outcome cannot be ascertained beforehand because the outcome is not pre-programmed into the physics. The kicker is we are told that the complex, information-rich structures that make up life’s diversity arose through purely chance means; as opposed to the natural means in which stars form. Now one of the reasons why I do not consider the option that it is God who is using naturalistic evolution is because the theory allows, and sometimes demands, that it can circumvent mindful design through chance and determinism. In other words, it attempts to explain away the need for God. You leave me with a series of good questions Dark. I don’t have the time to hit them now, but I hope to get to them as the Summer progresses. Enjoy.