Monday, May 08, 2006

Simon Conway Morris Agrees With Me

Maybe the title of this post should read "I Agree With Simon Conway Morris- At Least On One Thing." Here is the one thing: the Cambrian Explosion raises significant questions regarding Darwinian theory and reasonable persons are justified in questioning the validity of macroevolutionary theory on the basis of this evidence.

Morris is a leading paleontologist who was lionized in Stephen Jay Gould's book Wonderful Life because of his work on the Burgess Shale fossils of the Cambrian era. Here is what he had to say about the problems posed by the Cambrian era fossils in his book The Crucible of Creation: The Burgess Shale and the Rise of Animals (1998):
As our knowledge of the Burgess Shale has continued to expand, so it has reopened a whole series of questions that are relevant to the Cambrian 'explosion'. . . . By 1859 the problem had been more clearly articulated by Charles Darwin, in his Origin of Species. Darwin was fully aware that his theory might be difficult to reconcile with the seemingly abrupt appearance of the Cambrian animals. It is a testament both to the prescience of Darwin and the magnitude of the problem that to a considerable extent his articulation of the problem remains compelling and relevant reading today. p. 140-141.

Indeed, how can we explain the origin of so many forms of animal organization in the Cambrian? Did they appear almost simultaneously? Surely there must have been extraordinary mechanisms of evolution responsible for this, mechanisms that no longer operate today? Perhaps even the Darwinian paradigm of evolution, vigorously defended against all attack for more than a century, is now set to crumble before our eyes? Is not the sheer range of animals alive in the Cambrian far in excess of anything we see in modern seas? These are not absurd suggestions made by cranks and eccentrics on the fringes of science, but questions raised by reputable scientists. p. 164.

In the interest of honesty and full disclosure, he then states that in the next chapter he will explore why these ideas appear to be "flawed." And then he attempts to do so. But the rest of the book does not even begin to address all of the problems posed by the Cambrian Explosion. Moreover, I found his explanations fairly narrowly focused and far from convincing.

In any case, I quote him not for the proposition that he thinks "the Darwinian paradigm of evolution . . . is now set to crumble before our eyes." Rather I quote him because he believes that those who question the theory, and certainly those that believe that the Cambrian Explosion is solid scientific evidence that tends to undermine Darwinian theory, are not "cranks and eccentrics on the fringes of science" but that many are "reputable scientists."

While I am sure he is not a signer of the Dissent From Darwin statement, his comments can be viewed as a defense of the reasonableness of those who did sign. It also undermines the position of those who believe that teaching public school students about these fossils is unconstitutional.

* * *

For more on the Cambrian Explosion fossils, read here.


12 Comments:

At May 09, 2006 12:01 AM, Blogger Sean said...

By-the-bye, is there a Discovery Institute-alternative line on the Cambrian Explosion? Is there a suggestion that a menagerie of metazoan phyla were placed on the earth at this time?

 
At May 09, 2006 12:19 PM, Anonymous Lawrence said...

Sean,

My understanding is that the Discovery Institute does not have an official alternative theory. If there is any official position, it is that science has not given us a clear answer regarding the origin of these animals, and that allows for any number of possibilities. An honest "We don't know" is good science, when we, in fact, don't know. My understanding is that that is where science stands regarding the cause of the Big Bang as well.

What theory or explanation of the Cambrian Explosion do you find most plausible, and why?

Lawrence

 
At May 09, 2006 8:33 PM, Blogger Sean said...

Lawrence,

I am curious about this notion that science should admit "I don't know", and this could be considered "good science."

I'm not sure that there is a subject in science that when forced to admit "I don't know" it isn't followed with "but if I had to guess I would say [blah]." The Big Bang is an interesting case, because as far as I understand, the mathematics break down so much that anything before a certain time is open to wild speculation because there is nothing to suggest any certainty.

I remember an analogy of a person feeling their way around a dark room, bumping into furniture, feeling its shape and size. Eventually, they find a lightswitch and everthing is made clear, (including the door to the next dark room).

Saying "I don't know" is like standing in the corner of that dark room with your arms folded.

Sean

 
At May 10, 2006 12:57 PM, Anonymous Lawrence said...

Sean,

It is interesting that you think "Saying 'I don't know' is like standing in the corner of that dark room with your arms folded." I don't think that follows logically.

For me, saying "I don't know" is an invitation to find out, to explore, to discover, to consider all possibilities with an open mind, to be genuinely curious, to think outside the box, to ponder, to wonder, to be creative.

I note that you did not answer my question, and I am genuinely curious to know your answer: What theory or explanation of the Cambrian Explosion do you find most plausible, and why?

Lawrence

 
At May 11, 2006 1:21 AM, Blogger Sean said...

Hi Lawrence,

I didn’t want to be drawn into a discussion on Cambrian fossils. I’ve seen enough blog comments to imagine how it will go.

I’ll say something like how it looks like an explosive appearance due to rapid evolutionary change and the limits of previous technology to find soft-body microfossils in the fossil record before this time. Then you might say something like natural selection deals with small changes in DNA, so how does that account for large diversification? And I’ll say something like a small change in a gene may have a large effect, like the experiment when you can turn a fruit-fly’s antenna into a leg...and on we’ll go.

Let’s be honest: We’ll be trying to argue the nuances of something that is in neither of our fields of expertise.

I’m more interested in this notion of science admitting “I don’t know,” and what happens next.

When you say "I don't know" is an invitation to find out, etc, it makes me think your background is not in science. Just a feeling.

I’m not going to tell you “that’s not how science works.” Having said that, I’ll suggest a definition of science: science provides strong explanations about the world.

Have you considered that scientists support the theory of evolution not because of their education indoctrinating them, but because of the strength of the explanation?

Strong explanations are built on or replaced by stronger explanations, (if a stronger one exists.) Relativity and evolution are strong explanations. Astrology and Intelligent Design are weak ones.

Cambrian explosion is an interesting one. Palaeontologists find more information as their techniques get better, but the Cambrian explosion is not the silver bullet that kills evolution.

And until a better explanation comes along, science is going to keep evolution.

Sean

 
At May 11, 2006 2:13 PM, Anonymous Lawrence said...

Sean,

I don't blame you for not attempting to come up with an explanation of the Cambrian Explosion that is both consistent with Darwinian theory and plausible. But I disagree with your prediction of how the discussion would go.

Maybe you would answer one question- do you think kids who learn about evolution should be allowed to hear about the fossils of the Cambrian Explosion?

Ok, maybe two questions- what we learn from looking at the Cambrian fossils is that more phyla (arguably many more) than we have with us today appeared in a geological moment approx. 500 million years ago. After that, only one other phlya appeared in the 500 million years hence. Is that what Darwinian theory would predict?

I think the answer for any open-minded person is fairly obvious, and does not involve arguing "the nuances of something that is in neither of our fields of expertise."

Lawrence

 
At May 12, 2006 2:04 AM, Blogger Sean said...

Hi Lawrence,

I don't blame you for not attempting to come up with an explanation of the Cambrian Explosion that is both consistent with Darwinian theory and plausible.

Tee hee! I didn’t say that.

As for teaching Cambrian fossils: why not? I suppose as long as it is within a curriculum framework that makes sense. I know with us the curriculum deals with geological records in broad brushstrokes during high school, with the details at University.

...what we learn from looking at the Cambrian fossils is that more phyla (arguably many more) than we have with us today appeared in a geological moment approx. 500 million years ago. After that, only one other phlya appeared in the 500 million years hence.

From the papers I’ve read, I’d argue those numbers. There are about 20 metazoan phyla alone with extensive fossil records; only 11 appear in the Cambrian. Of the remainder, 1 is known to Precambrian and the other 8 first appear more recently...

...and suddenly we’re arguing the nuance of something that is in neither of our fields of expertise.

Here’s the trouble with arguing this sort of subject in the comments on blogs: we strive to nail the argument with one question or statement, usually snatched from a popular science book or a Discovery Institute info sheet. But in getting that one line, we lose a lot of detail.

A glance at the literature (as much as you can just glance at it!) of people actually working on the Cambrian fossils indicates that at their level, the Cambrian explosion is not the silver bullet for evolution that you want it to be.

Sean

 
At May 12, 2006 2:28 PM, Anonymous Lawrence said...

Sean,

You said,

"Tee hee! I didn’t say that."

I didn't say you said anything. I said you didn't do something- you didn't attempt to come up with an explanation of the Cambrian Explosion that is both consistent with Darwinian theory and plausible.

I am glad to hear that you support kids hearing about the Cambrian fossils. That puts you at odds with many of the lobbyists and outspoken supporters of Darwinian theory.

Regarding the number of phyla, I am curious to know where you came up with those numbers, and which phyla you think appeared after the Cambrian and when. Your numbers are not consistent with how Gould summarizes the Cambrian phyla: "Since then, more than 500 million years of wonderful stories, triumphs and tragedies, but not a single new phylum, or basic anatomical design, added to the Burgess complement." Wonderful Life, p.60. He may be off by a little, but I think you overstate it.

You keep insisting that we are stuck arguing nuance. I will get us out of that. Let's take your numbers hypothetically. That gives us this:

Eleven (more when you count the extinct ones) phyla appear with no obvious ancestors in a geological moment (5-20 years) approx. 500 million years ago, and they are the first record of complex multicellular life. Then eight phyla appear in the 500 million years hence. Is that what Darwinian theory would predict?

You said:

"Here’s the trouble with arguing this sort of subject in the comments on blogs: we strive to nail the argument with one question or statement, usually snatched from a popular science book or a Discovery Institute info sheet. But in getting that one line, we lose a lot of detail."

You seem to be saying that we cannot summarize the overall fossil record and ask if that is what Darwinian theory would predict. I think you can, Gould thinks you can, and I think any ordinary open-minded person would think you can. I have just taken the facts as you assert them and asked if they are consistent with Darwinian theory.

You said earlier,

"the Cambrian explosion is not the silver bullet that kills evolution"

I am not looking for a silver bullet to kill evolution. I accept aspects of evolutionary theory. I object to Darwinian dogmatism that unthinkingly asserts that microevolution proves all aspects of macroevolution. My position is that Darwinism is not a good explanation at all for some aspects of the fossil record and the history of life. The cause of the Cambrian Explosion remains a mystery, and honest scientists should admit this.

 
At May 13, 2006 7:45 AM, Blogger Sean said...

Hi Lawrence,

My phylum number came from Collins, some 10+ years after Gould's book. There's a summary here.

In general terms, then. (At risk of turning our debate into something like Christopher Columbus & the King of Spain arguing over the shape of the world in that Bugs Bunny cartoon... "It's a-rounda!" "It's a-flata!" "It's a-rounda!" "It's a-flata...!"

Yes, the fossil record is consistent with Darwinian Theory.

Yes, the number of phyla appearing over that period is consistent with Darwinian theory.

Just before we continue, [lunges for the dictionary] what's a phylum when it's at home? Phyla represent the largest generally accepted groupings of animals and other living things with certain evolutionary traits. It's the broad brushstroke of the classification nomenclature. How many more do you need?

Sean

 
At May 17, 2006 3:33 PM, Anonymous Lawrence said...

Sean,

As noted earlier, I tried to avoid quibbling about the exact number of phyla and when they appear by accepting your numbers hypothetically.

What I think is noteworthy is that you seem to have felt the need to answer a different question than the one I asked. I asked if the Cambrian Explosion is what Darwinian theory would predict. You answer a different question: "Yes, the fossil record is consistent with Darwinian theory."

I have seen how just about any data can be "shoehorned" so that it is "consistent with" Darwinian theory. But is the Cambrian Explosion what Darwinian theory would predict?

Lawrence

 
At May 18, 2006 11:00 PM, Anonymous Christian said...

This comment has been removed by a blog administrator.

 
At May 21, 2006 11:16 PM, Blogger Sean said...

Hi Lawrence,

I asked if the Cambrian Explosion is what Darwinian theory would predict.

Well, the short answer is "yes" with an "if".

The long answer is "no" with a "but"...

Let's make sure we're on the same page re:Cambrian Explosion. Are we both bearing in mind:

o not all living creatures become fossils?
o what fossils exist are just a blurry snap-shot of what happened at the time?
o Simon Conway Morris' comment "Oh fuck, not another new phylum!" shouldn't be taken as seriously as a lot of people do?
o "Cambrian Explosion" is a bit of a misnomer?

Also, are we on the same page as to what a scientific theory can predict, and that perhaps phenomena may not be directly predicted but still fit into the framework of the theory?

Cheers,

Sean

 

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