Prior to their rediscovery, it was believed that Coelacanth were one of the first aquatic creatures that experimented with walking.
Scientists never believed that the ancient Coelacanth actually walked in some incipient way. The fossil Coelacanth was thought to be a relative of the Rhipidistians, a fish species ancestral to the tetrapods (land animals like us), and that is how the Coelacanth is still viewed today.
So even supposing the modern Coelacanth is vastly different from the fossilized ones, we know that assertions about their "walking" is a total fabrication.
Well, yes, it is a total fabrication. By you. Scientists never claimed the ancient Coelacanth walked.
After a battle a missing soldier may be classified as "missing, presumed dead." Finding the missing soldier is not an embarrassment, nor is it an invalidation of military battle procedures. In the same way, an ancient fossil with no known descendants is usually classified as "presumed extinct". Finding modern living relatives is not an embarrassment, and it is not an invalidation of paleontological procedures or analyses. The creationist misuse of the Coelacanth example is just another form of the familiar creationist misunderstanding of evolution best exemplified when they ask, "If man is descended from monkeys, how come there are still monkeys?"
One time ago, didn't we already dismissing this embarrassing notion you have of "stump-like appendages"?
No, not at all. In fact, you neglected to actually answer the question. Obviously if avian descended from therapods, the wing must have developed slowly- lest you believe in a hopeful monster.
I answered the question just fine and you never responded to it. Do you wipe your memory every time to log back into EvC?
Wings did develop slowly, multiple times, in multiple species of creatures.
1. What kind of a crude protowing began?
Its called an "arm". If you look at your keyboard right now, two of them are attached to the hands you are using to type.
2. How didn't it inhibit its survivability?
Because these "arm" things are incredibly useful as I am sure you can imagine.
3. What advanatageous qualities did it have?
For proto-birds catching prey and sexual displays, for us typing message on the internet.
4. What prompted the changes to begin with?
Exaptation of already feathered arms for gliding and subsequently powered flight, eminently recorded in the fossil record.
Surely, though, you understand that numerous successive gradations must taken place. Where are the remains?
Why don't we have any fossils of any creatures in the midst of transition?
We do! You absolutely refuse to look at them!
Why are they all fully formed?
Because they have to be. Not being fully formed means you die. No body EVER SAID that evolution needs non-full-formed intermediates. In fact it says quite the opposite.
How many long pages of debate did we take up trying to describe this exact thing? Each stage in the evolutionary process needs to be viable. Because of the well understood and observed process of exaptation, you don't need to start with "stump like appendages".
What good is half a wing? When it is a feathered arm, its pretty darn good.
Edited by Jazzns, : No reason given.
Edited by Jazzns, : No reason given.
Edited by Jazzns, : No reason given.
Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)
Can we just both agree that the question, "If we all came from monkeys then why are their still monkeys?" is a stupid and invalid question to ask?
nj writes:
Yes.
Apparently you still have no idea WHY it is a stupid question because you continue to misconstrue the issue with regards to creatures such as the Coelacanth.
Steps to a "new" feature ... and back to the topic
Each stage in the evolutionary process needs to be viable. Because of the well understood and observed process of exaptation, you don't need to start with "stump like appendages".
Getting back to the original topic - mutations of new body parts -- what we see in these instances (fish legs and dinosaur wings) is that there is no single mutation that creates a new part, but a series of mutations that change the structure of an existing feature into something different that is then used differently and further adapted for that secondary use.
This is a two-step process, the first one takes variation and diversity within existing populations that provides an opportunity for a secondary use of an existing feature while still providing the primary function, while the second fine tunes the secondary use and turns it into a primary function.
Hi I am new to this forum and thought I'd give my two cents on this issue. Although most likely the original poster is a creationist, not all critics of evolution are creaionists. I happen to be of the few who are skeptical of both neo-Darwinism AND intelligent design. I for one do not believe that either side can adequately explain the great question of our origins. I don't necessarily have a problem with the notion that organisms have evolved over time, rather, I have a problem with the MECHANISM proposed by Darwinists. Despite what many of you Darwinists claim, the mechanism of evolution is NOT securely founded. Natural selection acting on random variation caused by genetic mutations cannot possibly account for the complexity and diversity of life on Earth. Many claim that the natural selection of mutations is a sufficient mechanism by which organism can evolve from lower forms, and acquire new features that did not exist in lower forms. However, such a mechanism falls very short when it comes time to explain the emergence of many complex features such as new body plans (most notably the differences among the animal phyla), the emergence of bone structure, novel organs, etc. The evidence shows that mutations do not produce the kind of genetic variation necessary for the appearance of these novel organismal features. Even if they did, how do we account for many of the delicate, finely-tuned processes that exist at the biochemical level? (such as cellular respiration, mitosis, the Kreb's Cycle, etc.)? Obviously these processes can't come about by natural selection of mutations, since "cellular respiration" doesn't have anything to "mutate", if you catch my drift. How can variation of biochemical processes come about? Obviously something is missing here. It really seems to me that most Darwinists fail to understand the implications of many of their claims. So am I saying that God did it? Not by any means! I think the there is a higher probability that there are naturalistic explanations that can account for life than a supernatural creator having done it. However, it seems that right now we simply don't have it all figured yet, despite claims to the contrary by many close-minded Darwinists.
"Neo-Darwinism is an attempt to reconcile Mendelian genetics, which says that organisms do not change with time, with Darwinism, which claims they do." - Lynn Margulis
The evidence shows that mutations do not produce the kind of genetic variation necessary for the appearance of these novel organismal features.
What evidence would that be?
Even if they did, how do we account for many of the delicate, finely-tuned processes that exist at the biochemical level? (such as cellular respiration, mitosis, the Kreb's Cycle, etc.)?
Descent with modification and natural selection.
Obviously these processes can't come about by natural selection of mutations, since "cellular respiration" doesn't have anything to "mutate", if you catch my drift. How can variation of biochemical processes come about?
Descent with modification and natural selection.
Obviously something is missing here.
Yes, your understanding of the power of descent with modification and natural selection.
However, it seems that right now we simply don't have it all figured yet, despite claims to the contrary by many close-minded Darwinists.
Claims of "we don't have the real answers yet" deserve little attention in the absence of alternative proposals.
The webpage you're drawing the Lynn Margulis quote from, Neo-Darwinism: The Current Paradigm, part of the Cosmic Ancestry website that advocates panspermia, contains numerous inaccuracies. The author, Brig Klyce, has a weak grasp of his material.
If panspermia is where you're going, it doesn't answer the questions you raised about the origin of such things as the Krebs Cycle and so forth.
Why haven't we seen a single instance where a new body part has been introduced? (not duplication of body parts)
A Body Part is any part of an organism, such as liver, lungs, stomach, leg, finger, etc.
A new body part is any body part that was introduced to an organism that was not there before, either in the organism itself or the entire population of that particular species.
To get a little more on topic, completely new organs have evolved many times, but of course this takes more than one generation. This happens in at least two main ways.
One - begin with a small change, then add changes, each giving an advantage, until what you have can be called a “new organ”. Eyes are the classic example of this. First, start with regular temperature sensitive nerve cells (we can evolve their presence in steps too if you like). Now, a mutation causes them to fire when exposed to light instead of heat - not hard since light produces heat anyway. Now there are a clump of light sensitive cells, which are advantageous because sensing light is better than not sensing it - this may allow the little creature to hide under a rock, etc. Now a mutation causes that clump to be depressed in the skin - thus protecting it. Similarly, you can see that the opposite mutation - causing it to bulge up, would be selected against, so the “depressed in” mutation survives. Now the cup with light sensitive cells can sense light direction too! Mutations that cause a transparent cover of cells, and later thicken this layer to make a lens, or add muscles that allow the eye to move are all accumulations of small steps, each being advantageous, up to the eye you possess. At what point was it a “new organ”? Certainly not when it was just a few light sensitive cells! This is why your question is somewhat like “How could my family have a dozen lineages now - don’t we have to create a new lineage from scratch, and then how could it be my family?”.
The other way, as many have pointed out, is the exapatation - where something is selected for one environment, but then is later selected for another one. In addition to the classic example of the wing discussed already, the breast is a neat example. Did fish have milk- producing breasts? Of course not. Early in our mammal line, when our ancestors were much like lizards, a mutation caused excessive sweatiness, at least in one location of the body. This creature’s babies were able to lick this sweat and gain some nourishment. Obviously, mutations that made more sweat in that area in females would be selected for because their kids would have a better chance of getting fed. So small steps caused the breast to form, (note that there are still some mammal species today that don’t have nipples), finally giving us the mammal breast. Add to that that sexual selection of hominid males who looked for women that had capable breasts, and you can see where the selective pressure to add fat to “artificially” enlarge the breasts would come from. That’s why human breasts today are “fat padded” to make them much larger (in many cases) than they need to be for nursing a baby. So when did this “organ” come into being? Certainly not just when there was some sweaty skin!
There are a lot more examples too. Another good one is the poison delivery system in rattlesnakes.
Also - note that this same method works even better on a DNA level, where one can mutate a whole copy, then change the copy to make a completely new gene.
"Descent with modification and natural selection."
Sounds good and all, but you have to remember that "modification" comes from selecting variation, which comes from mutations, according to Darwinism. After all, mutation is the ultimate source of variation for natural selection to act, right? So at the biochemical level, this mechanism would fail. Organic molecules and enzymes can't "mutate" because they don't host a genome.
"Claims of 'we don't ahve the real answers' deserves little attention the absense of alternative proposals"
Well, like you mentioned, there are in fact alternative proposals besides creationism. I brought up Lyn Margulis to illusrate that there are many manstream scientists who are not creationists yet do not embrace Darwinism because of the evidence. Fred Hoyle was a staunch atheist, yet knew that selection and mutation alone could not possibly account for the complexity of life, which is why he forulated his own theory of evolution: that novel genetic material is inserted into the genomes of organisms by viruses from outer space. As far fetched as it sounds, his theory is in fact compatible with the evidence. Lynn Margulis was highly skeptical of evolution and laughed out of conferences for advocating her theory of symbiogenesis. Today, her endosymbiotic theory of the origin of eukaryotic cells is now almost universally accepted. So maybe it isn't always a bad thing to question a theory. No doubt about it, many Darwinists do in fact believe they have it ALL figured out. wouldn't you agree that some Darwinists such as Richard Dawkins use evolution inappropriately? After reading several of his books, I would have to say he is not really all that interested in the science behind it. Rather, it seems to me that his agenda is to use evolutionary theory first and foremost as a weapon against religion. Not that I'm defending religion in any way, shape, or form, but this is not the purpose of science. I've always felt that science is the the pursuit of truth and explanation about the natural world.
So at the biochemical level, this mechanism would fail. Organic molecules and enzymes can't "mutate" because they don't host a genome.
The genome that encodes these proteins and enzymes is what mutates, obviously. And we've made observations that show that mutations are capable of more than enough diversity to account for all living things (and then some, by a factor of one thousand to one.)
I brought up Lyn Margulis to illusrate that there are many manstream scientists who are not creationists yet do not embrace Darwinism because of the evidence.
Lynn Margulis has a penchant for dramatic overstatement, that is all. She's a firm supporter of the evolutionary consensus, and of descent by modification by natural selection and random mutation, just like all other serious biologists. Please, don't try to read her mind from the things she says in public. Unless you're reading her journaled papers, you're not getting the whole story, and you're drawing conclusions from faulty evidence.
Fred Hoyle was a staunch atheist, yet knew that selection and mutation alone could not possibly account for the complexity of life, which is why he forulated his own theory of evolution: that novel genetic material is inserted into the genomes of organisms by viruses from outer space.
As Percy has alluded to, panspermia has a chicken-and-egg problem. Where do the viruses come from? How did they evolve? It doesn't solve any of the problems its adherents claim need to be solved, it just pushes them to another world.
As it happens, though, mutations are capable of vastly more genetic diversity than we see in living things, so its abundantly obvious that mutations are sufficient to account for the diversity of living things.
Lynn Margulis was highly skeptical of evolution and laughed out of conferences for advocating her theory of symbiogenesis. Today, her endosymbiotic theory of the origin of eukaryotic cells is now almost universally accepted.
Indeed. Lynn Margulis is a brilliant evolutionary biologist who puts her ideas to rigorous test, and then publishes the results for peer-review. Which are things the creationists absolutely refuse to do, because then all would see the intellectual bankruptcy at the heart of their position.
I've always felt that science is the the pursuit of truth and explanation about the natural world.
There are religions in the natural world - just look around you - and religions make claims about the natural world. Debunking those claims and studying the phenomenology of religion are appropriate venues for science, despite your feelings.
Alright well thanks for your input and feedback on my ideas. I'm only 20 and obviously not nearly as well read as you guys are in matters pertaining to evolutionary biology. I've just been very intrigued by questions about our origins ever since taking some freshmen biology classes in college. Although I might have come off sounding like it, I am not a creationist or IDist. I simply believe that perhaps there is much more than what we currently know. And I have to admit to Percy that the cosmic ancestry website that he mentioned is what got me to thinking that there might be a third alternative to Darwinism and Creationism. Not necessarily panspermia, but maybe something we haven't yet discovered. Who knows.
I simply believe that perhaps there is much more than what we currently know.
That's certainly true, but do try to remember that, with just a freshman-level biology class, there's much, much more than you currently know, too.
For instance we've actually performed experiments that result in the evolution of "irreducibly complex" genetic structures via mutation and natural selection. You probably didn't cover those in freshman biology, for instance.
I'd suggest going the next step and taking a higher-level genetics or biochemistry class if you're interested. It's a lot harder to learn this stuff on your own, trust me.
"I'd suggest going the next step and taking a higher-level genetics or biochemistry class if you're interested. It's a lot harder to learn this stuff on your own, trust me."
Well this is precisely what I will be doing in the next two to three years during my undergraduate studies. I am a biology major and love absolutely love biology. Unfortunately the only bioloy classes I have under my belt are Gen. I & II, Plant Morphology, Natural Vertebrate History, Biogeography, and Genetics I. So obviously I stil have a quite a bit to learn. However, I have stumped several of my PhD Biology professors with some of the questions I have brought up on this forum, mostly regarding the mechanism(s) of evolution and the Cambrian Explosion. It sometimes seems like they don't know much more than what they've been taught in their graduate textbooks. I'm just a very curious and inquisitive person who always takes what anyone tells me with a grin of salt. I hope to be able to contribute to some of the fascinating discussions on this board as I learn and grow during my studies in the biological sciences. Perhaps I shouldn't have but into this thread, but the whole idea of "how" evolution works has been a big interest of mine. Thank you,
"I'd suggest going the next step and taking a higher-level genetics or biochemistry class if you're interested. It's a lot harder to learn this stuff on your own, trust me."
The way you can use these cool quote boxes to help make the quotes stand out is
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quotes are easy
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also check out (help) links on formating questions when in the reply window.
However, I have stumped several of my PhD Biology professors with some of the questions I have brought up on this forum, mostly regarding the mechanism(s) of evolution and the Cambrian Explosion. It sometimes seems like they don't know much more than what they've been taught in their graduate textbooks. I'm just a very curious and inquisitive person who always takes what anyone tells me with a grin of salt. I hope to be able to contribute to some of the fascinating discussions on this board as I learn and grow during my studies in the biological sciences.
You may only be dealing with grad students rather than full professors, but they should take you question and find the answer if they don't know.
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