Talk:Cambrian explosion contradicts evolutionary tree pattern

From EvoWiki

I removed these two response-responses from the article:

• (to response #1) "This is highly speculative. Many of the matches are superficial and problematic. For example, there are no definite Precambrian arthropods, and the candidates present many matching problems, such as no limbs and no internal digestive system. Arthropods are defined by jointed limbs. Plus, many of these forms dissappear from the fossil record for roughly 10 or 20 million years before the Cambrian. (This is nicknamed the "small shelly era".)"
• (to response #2) "Tell me one of the earliest known chordates does not resemble a fish [1]."

For the first response, there is far more to arthropod identification that merely the presence of jointed legs. Any trilobite expert can tell you that. Not all of the Edicarans are thought to have been arthropods. However, those that are thought to have been arthropods are thought to be because of their similarities to the larval forms of trilobites, as well as their similarities to some of the various non-trilobite arthropods from the Cambrian.

• Yes, but that is not a universal opinion, and probably not the majority. Each researcher seems to have their own pet theory. I have yet to read a settled, consensus opinion on that.

Do you have actual proof of this beyond your own personal opinion?--Mr A. 15:01, 12 March 2007 (UTC)

Do you have proof there is a consensus, or is it your personal opinion?

For the second response, the Cambrian chordates do not look like the vertebrates that we humans refer to as "fish." The oldest true "fish" appeared during the Ordovician period, such as Arandaspis, Sacambabaspis, and Astraspis. The Cambrian chordates resemble the non-vertebrate chordate known as the "Lancet" or "Amphioxus."--Mr A. 21:15, 14 January 2007 (UTC) "Origins of Trilobites"

• The word used was "not anything like". Those recreations look like a fish, or at least a close cousin to me. And if they were merely big Amphioxus's, that would not mean much other than Amphioxus was around at the time.

Your opinion is besides the point. Amphioxus is not a vertebrate, and there were no vertebrates during the Cambrian. The fact remains that the very first proof of vertebrates is from the Ordovician, millions of years after the Cambrian Explosion ended.--Mr A. 15:01, 12 March 2007 (UTC)

That is not the point. Please reread. "True fish"-ness is not the issue. It said "resemble", not "is". I am not talking about formal classification, but general body plan. Bony spines does not change the big picture.

The vertebra is not part of "true fish-ness"? That sounds really crazy to me. You seem to expect that the Cambrian ancestors of vertebrates have absolutely nothing in common with vertebrates - but then, how would biologists be able to tell they are their ancestors? --tk (t) 08:17, 13 March 2007 (UTC)

Again, that is not the issue. You answered a question I didn't ask.

Amphioxus was not a fish, the Cambrian chordates were not fish. What point are you trying to get across?--Mr A. 05:24, 14 March 2007 (UTC)

My argument didn't depend on it being a fish.

Then what point are you trying to make? When you said "Tell me one of the earliest known chordates does not resemble a fish," it was strongly presumed that you were making the assumption that the Cambrian chordates WERE FISH.--Mr A. 13:17, 16 March 2007 (UTC)

Removed from the article:

"This is speculative even among experts. There is no consensus about matchups between pre-Cambrian and Cambrian forms. Many experts even speculate that pre-Cambrian forms were a dead-end evolutionary experiment; a branch of the tree that died off. Even if they were the ancestors of Cambrian forms, there appears to be a relatively sudden jump or change in form in all of the lineages near the boundary and this transaction has not been found in the fossil record. This does not fit the idea of gradual change and independent branches. Perhaps there was some change in environment or preditor character that affected them all, but so far the evidence is illusive and it is fair to say that the Cambrian Explosion is probably the primary open mystery of evolution."

Do you have specific sources for these claims? Which experts are saying that all of the Precambrian organisms were dead-ends?--Mr A. 06:30, 4 March 2007 (UTC)

Gould quotes and seems to agree in his book, "Wonderful Life". It is near the same page as the categorization diagram of the Precambrian organisms.

You fail to realize that scientists have come a long long way since Gould's book, especially since we've been able to identify what Hallucigenia was, and that Anomalocaris had legs. It would behoove you to update your information, like reading "The Origin of Phyla," which is a far more accurate book.--Mr A. 15:01, 12 March 2007 (UTC)

Well, if you have new evidence about precambrian biota, then present it. I gave a citation. If you don't like it, counter with another citation.

What's so difficult to understand about "The Origin of Phyla"? See this page [2] --tk (t) 08:17, 13 March 2007 (UTC)

Thank You for the reference. That is how it should be done.

And why couldn't you looked it up yourself in the first place? You don't know how to use Google or Amazon.com?--Mr A. 05:24, 14 March 2007 (UTC)

Yes, that's the point I tried to make. Giving you the Google page should have told you, "Look, you already have all the information you need. All you have to do is enter the title of the book in Google, and voila, you get a link to the book on Amazon." And you should have answered, "Oh, you are right. Sorry for being dense." --tk 07:50, 14 March 2007 (UTC)

If the actual text is *on* the web, then please link directly to the page rather than a general book brochure.

You keep missing the point. Apokryltaros gave you the title of a book, and the title of the book is enough to find out how to get the book, as I demonstrated above. When you asked, "counter with another citation", you already had that citation. Now either accept it or go away. Either buy the book or lend it from a library or drop the question. Apokryltaros did not complain about your giving just the title of Gould's book either.

Why is it that people who think that creationist arguments have merit are always people who don't know how to find out whether arguments have merit? --tk 09:07, 15 March 2007 (UTC)

---

"How is "less primative" being measured? Is there a study that says a short-thick holdfast is less effective? If so, a mere change of shape shouldn't take tens of millions of years to evolve. Mere change in shape is generally considered a relatively easy thing for natural selection to perform. Look at what we did with wolves-to-dogs."

If you actually understood what was written, you would have realized that the statement was not talking about the holdfasts of primitive eocrinoids being less effective than the holdfasts of later eocrinoids, it was stating that the trend in eocrinoid evolution was from thick holdfasts to thinner holdfasts.--Mr A. 06:30, 4 March 2007 (UTC)

Note that I object to your rudeness. Now, back to the topic. Again, mere change in basic shape does not require millions of years if the selective forces on shape are simple. Stems growing fatter over time does not say much other than stems grew fatter. If you can define "less primative" as you please, then you win the argument by circular reasoning alone. The stem shape is perhaps due to a change in the environment over time (more salt, faster preditors, shifting niche, etc.) rather than the number of generations of the given organism.

In short, you guys are exaggerating the case.

First off, you fail to comprehend that I have very little patience for people, like yourself, who routinely disregard everything I say, save to cherrypick little points with which to misconstrue. So, in other words, unless you wish for me to actually become actively hostile, please continue to point out my alleged rudeness as a valid talking point at your own peril. Furthermore, you have missed the point entirely, in that one of the main definitions of "primitive" is what the oldest forms looked like, and that evolutionary trends are defined by comparing older species with younger species. Your alleged claim that a change of form wouldn't need to take tens of millions of years contradicts directly with your previous claim that the transition from the Precambrian to the Cambrian is too should of a time to provide extreme diversity. That you continue to ignore the fact that the evolutionary trend of eocrinoid evolution (from their appearance in the Cambrian to their extinction in the Silurian) was to go from thick holdfasts to long thin stalks serves only to cement the fact that you continuously disregard whatever I say.--Mr A. 15:01, 12 March 2007 (UTC)

I read it again, and still conclude that you are exaggerating. A fatter/thinner stem hardly justifies anything of significance. A more important issue is that eyes, limbs, and clear digestive tracks appear to lack before the Cambrian. I am not a creationnist, but I can see why people like you piss them off and fire them up. Personal certainty to the point of arrogance in the face of fuzzy evidence is something I expect of religious zealots.

A gross inability to understand that stems and holdfasts are vital anatomy to eocrinoids is something that I expect of a pseudoscientist.--Mr A. 13:10, 13 March 2007 (UTC)

That is argument-from-authority. That is not presenting evidence. And I did nothing to deserve the IP ban other than ask difficult questions. Is censorship the way to science?

I'm sick of the pointless, and disgustingly drawn-out arguments you make, and I'm sick of the fact that you don't listen to anything I say, and I'm sick of the fact that you have yet to contribute anything positive to any of these talk pages. I warned you that my patience with you has worn thin, and you continue to ignore that, still. As far as I know, you're just a troll peddling pseudoscientific nonsense.--Mr A. 05:24, 14 March 2007 (UTC)

I've read your replies 5 times, and I see nothing of significance I've done wrong. It appears that you are the poor communicator, not myself. And, somebody with "thin patience" isn't qualified to be a moderator and possess IP ban rights. I suggest your ban rights be relinquished to somebody more cool-headed and personable.

Apokryltaros, as the saying goes, does not suffer fools gladly. If the day comes when he overdoes that, other admins can revert his actions. At the moment, I can't see any overdoing. You just have the wrong idea about what "primitive" means, and he does. Why don't you just accept that? Why don't you just admit that you were wrong? That would show the people you discuss that you are hearing what they say. After that, you can still disagree in other points. That attitude you have is all too common among evolution critics. --tk 09:07, 15 March 2007 (UTC)

Being wrong, even if the case, is not a reason for being banned. You don't look like an open-minded site by acting like Soviets. And, "primitive" is perhaps a word that should be retired. If you mean "older", then say older. "Primitive" lacks precision and invites miscommunication. Sometimes it implies lack of features, but lack of features and age are not necessarily related. Some lines lose their eyes, for example. As far as "not listening", again I read it 5 times. Note that the wikipedia article on C.E. is a lot more mild about claims, and seems to fit what i've read about ediacaran's from other experts. A broader survey may be more useful than a tit-for-tat citation battle of individual authors perhaps. I would bet a paycheck that a concensus would be that there is no consensus on what the ediac's really are.

Among other things, "primitive condition" is synonymous with "ancestral condition." It is hypocritical of you to say that I'm using misleading statements when you claim that you're not insisting that the Cambrian chordates are not fish, nevermind that you stated, "Tell me one of the earliest known chordates does not resemble a fish," nevermind that whenever the statement "tell me X does not look like Y," is used, it carries the unstated implication that X is Y because they look similiar. You are argumentative and dense, and tediously repetitive in the way you disregard all points that disagree with your own. You were originally banned because I had warned you not to continue mistaking my attempts at emphasizing my points, which you've consistently dismissed I might add, as being rudeness. When you ignored that warning you were banned. I continue to block the IPs that you use to return here because it's a form of ban-evasion. That you insist on saying that we're all closeminded communists because no one has decided to veto my decision is not winning you any sympathy, either.--Mr A. 13:17, 16 March 2007 (UTC)

Punctuated equilibria

Even if it was rapid change it still fits another model of Evolution called Punctuated equilibria which allows for long periods of little or no change interrupted by quick sudden change.--Fang 23 15:20, 4 March 2007 (UTC)