A signature of a radiation in metazoan evolution

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How real is the Cambrian explosion? In a sense, it wasn't an explosion at all in any commonly understood meaning of the term—it was a relatively rapid apparent diversification of animal phyla over the course of at least tens of millions of years, at a rate that is compatible with unexceptional rates of evolution. Even at the most 'explosive' rate that can be inferred from the observations, this is not an event that challenges evolutionary theory, nor should it give comfort to creationists of any stripe.

However, there are controversies here. One camp holds that the rapid divergence of the metazoan phyla in the Cambrian is real: the different phyla all arose sometime around the boundary, 543 million years ago, and then evolved into the various forms we see now. This interpretation is supported by the fossil record, in which the first recognizable representatives of the phyla are found from roughly the same period.

Another interpretation is that the Cambrian explosion is only apparent: that the divergence occurred well before 543 million years ago, and that there was a long period of undetectable evolution. The major groups of animals separated 600 or perhaps even as much as 700 million years ago, flourished as small wormlike forms that would have fossilized poorly, and what the Cambrian represents is an emergence of larger forms with hard body parts that fossilized well. Some of the molecular data supports an early divergence, and there are known pre-Cambrian trace fossils and fossils—the phosphatized embryos of the Doushantuo formation, about 600 million years old, are a good example.

There are also other ambiguities to be resolved. The relationships of many animal phyla are confusing, and who branched from whom remains to be resolved. In the diagram below, the dashed lines in the tree are the problem: do they branch exactly as shown? How deep in time do those branches go?

metazoan radiation
The fossil record and evolution of 9 of the 35 currently recognized metazoan phyla suggest that most animal phyla diverged/arose at the beginning of the Cambrian (C) period. The thick lines represent the known ranges of fossils from their first appearance in the fossil record. Thin lines represent the inferred metazoan phylogeny based on fossil data. Dashed lines represent an amalgam of three conservative estimates of the inferred metazoan phylogeny.

Continue reading A signature of a radiation in metazoan evolution (on Pharyngula)

143 Comments

I see it as a slow-burning damp squib with a few phuts from time to time.

I wouldn’t doubt that many of the splits go back before the visible explosion in the fossil record. From my readings on The Ancestor’s Tale and elsewhere, it looks like the primate/mammal split occurred 70 million years ago, which is before the dinosaurs died out 65 million years ago, and the split between the dinos and the lines that would become mammals and marsupials (Dimetrodon, though it looked like a dinosaur, was a pelycosaur on our branch, not theirs) occurred before dinosaurs actually walked the earth.

There are a lot of things that evolved a long time before we colloquially think of them (colour vision and blood groups, for example) - it would in my mind be likelier that the shared traits predate the ability to be fossilized, and that the ability to be fossilized evolved separately due to climate change or an ‘arms race’.

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We are worms.

Odd that the fungus should be so neat, though.

I was aware that the Cambrian explosion is still the subject of some debate.My understanding(for what its worth),is that the explosion may have been precipitated by several environmental changes in and just before this period.Varangian glaciation gave rise to a rapid climate change which covered nearly all the oceans with ice.This was followed by rapid global warming,which vacated many new environments and provided the impetus for rapid evolution.Of the 20 or so metazoan phyla,around 11 appeared in the Cambrian, of the rest, only one has been found to be pre Cambrian, the others appear more recently

Note that there are plenty of precursors. Here are a couple: Small bilaterian fossils from 40 to 55 million years before the cambrian and a slightly larger Proterozoic modular biomineralized metazoan from a few million years prior to the Cambrian. There is a rumor that Prof. Steve Steve will show us some more Ediacaran creatures one day soon. Sorting out the family tree is the problem.

This is old news. I wrote in Sept. 2000:

“The real issue is that for a very long period of time there were only unicellular organisms, bacteria, algae, etc. and then at one point in time, somewhere around 600 m.y.a., a great leap foward occurred and multicellular animals made their appearance all at once, and in a very short period of time. All of the invertebrate body plans were ‘found’ if you will, in a period of time that was ‘the blink of an eye’ in evolutionary and geological time. After that time, no new body plans were ever found again. One must wonder why this was so. You can fiddle with the dates and the boundaries, but you can’t ignore the larger picture of sudden, widespread appearance of a multitude of different groups of invertebrates. I don’t think that this is a scenario that favors the mechanism of mutation and natural selection, which calls for the gradual accumulations of beneficial mutations over long periods of time. And why so many different kinds of animals? And how did they come to be distributed world-wide? These are the questions that keep me awake at night.”

and this:

“I agree that all living organisms are related and probably had a common origin. My question addresses the adequacy of copying errors and selection to create the complex and varied body plans that we see appear in the lower Cambrian. You agree that no one knows the cause of the Cambrian explosion, but why are you so repelled by the possibility that new genetic material may have been introduced from outer space? This is a common reaction that I encounter wherever I go to talk about this subject. Har-har-har-de-har-har!!! Genes from Space…Right!!!

It seems to me like a plausible alternative to the problem posed by the evidence. And by the way, I’ve never believed, and still do not believe that major adaptations of new processes, structures etc. can ever be driven by environmemtal changes. When I first heard the theory about human-chimp divergence being brought on by the ancestral populations being separated by geological changes, I damn near laughed my ass off. And the oceans…there’s a poser. Conditions on the sea floor are fairly uniform from one place to another, yet evolutionists would have us believe that the thousands of different species that live there evolved as a result of differences in their environment. The evidence for space genes is there, we just have to uncover it. It may take time. We gave darwinism 140 years to find the transitional fossils, and yet, they’re still missing, just like they were in 1859. Maybe you could give us panspermists a few more years, ok?”

and this:

“Darwin himself was more than slightly concerned about the ramifications of the Cambrian explosion. In his book he writes: ‘Consequently, if the theory be true, it is indisputable that before the lowest Cambrian stratum was deposited, long periods elapsed, as long as, or probably far longer than, the whole interval from the Cambrian age to the present day; and that during these vast periods the world swarmed with living creatures. (Ch 10, pg 313) Now Darwin, following the only path available to him at the time, explained this problem as an artifact of preservation. Walcott, in his analysis of the Burgess fauna, took the same position, that the ancestry of the Cambrian fauna was concealed in sediments that were now buried below the oceans. Now, in the year 2000, it is clear to us that these rock layers are not missing. In addition, paleontology has revealed to us the rocks of the pre-cambrian (vendian) are not totally devoid of fossils. While there is some evidence for a long period of pre-cambrian evolution, the appearance of diverse, shelly fossils is sudden, wide-spread, and remains an enigma. It is clearly not an artifact of inadequate preservation. Now, turning to the time periods involved. I think that it’s safe to say that this still remains a controversial issue. I will certainly grant you 20 million years from the Vendian to the first appearance of small, shelly fauna. But the Cambrian explosion is not just a story of hard skeletons, as seen in the Chengjiang and Burgess fauna. Large numbers of soft-bodied groups are represented in a well preserved state, and in widely diversified form. This rapid diversification in the lower Cambrian established all of the major body plans that are present in modern fauna. It is also safe to say that there is still much discussion and disagreement among the experts themselves as to the relationships of some of the groups, as well as how rapidly the metazoan radiation occurred and what triggered it. In short, both the Chengjiang and the Burgess have presented scientists with as many questions as it answers. Now if you look at the very oldest of the fossils, they are found in rocks of about 650-700 million years ago, although some doubtful examples have been found in older rocks. But it nowhere approaches Darwin’s hope that during these pre-cambrian times “the world swarmed with living creatures”. Where there metazoans in the pre-cambrian? Of course there were. But the “explosion” that is referred to, is not the appearance of metazoans, but the burst of innovation, and the rapid diversification of not only metazoans, but algae and protists as well. Many explanations have been offered for this momentous event, including changes in the physical environment, critical levels of oxygen in the atmosphere and changes in the chemistry of the oceans. But any plausible hypothesis has to also account for the expansion of soft-bodied groups as well as skeletons. Other explanations are organism centered, rather than environment centered. Examples include larger size, which may have triggered an increase in complexity or the development of life strategies, such as predation. However, in spite of all the hypotheses, no one emerges as a clear and satisfactory explanation and the emergence of metazoans remains a central enigma in biology today. I myself find most of the suggested explanations less than satisfying. We do know, however, that it appears that nearly a billion years passed with no movement towards multicellularity, and then at one point in time, a very rapid expansion and diversification of multi-cellular organisms occurred. It also appears that while some simple metazoans did exist in older rocks, the burst of innovation and diversification was indeed rapid and widespread, and occurred in a rather short period of time. Now we can argue till kingdom come about what happened but the fact remains that we weren’t there and we have damned little evidence to go on. Therefore I suggest that we follow this path. Continue to collect data, and hopefully in the near future an explanation will emerge that is clear and convincing. But I think that it’s unscientific, given the present uncertainty, to rule out the extra-terrestrial immigration of genetic material from outer space. You don’t eliminate a hypothesis just because you don’t like it, or even because there’s no present evidence for it. You rule it out if and when it is clearly demonstrated to be false.”

Sean (and his associates), while I admire his work, is clearly behind the curve on this.

Read the whole thread HERE: tinyurl dot com/7mcz8

Paul replied:

“Charlie, Carroll and company have something you don’t: data.”

I replied:

“Agreed.

And their data supports the views I have been expressing for many years. The cambrian explosion was real, not an artifact and the paleo data is stronger than the molecular data. You wrote: “One camp holds that the rapid divergence of the metazoan phyla in the Cambrian is real: the different phyla all arose sometime around the boundary, 543 million years ago, and then evolved into the various forms we see now. This interpretation is supported by the fossil record, in which the first recognizable representatives of the phyla are found from roughly the same period. Another interpretation is that the Cambrian explosion is only apparent: that the divergence occurred well before 543 million years ago, and that there was a long period of undetectable evolution. The major groups of animals separated 600 or perhaps even as much as 700 million years ago, flourished as small wormlike forms that would have fossilized poorly, and what the Cambrian represents is an emergence of larger forms with hard body parts that fossilized well.

The former view is strongly supported by observational data from the fossil record. The latter view is easily debunked (as I stated 5 years ago) by the fact that large assemblages of soft bodied fossils have been discovered in the Burgess and Chengjiang and none show the evidences for these presumed but undiscovered forms.

Credit where credit is due, Paul.”

I’m not so sure that it’s a good idea to try and deny the reality of what happened in the Cambrian. the point is valid and you would be well advised to concede it.

Spectacular Fossils Record Early Riot of Creation” by John Noble Wilford New York Times April 23, 1991

“New fossil discoveries in China hailed as among the most spectacular in this century, show the dramatic transformation of life from primeval single-celled organisms to the complex multicellular precursors of modern fauna was more sudden, swift and widespread than scientists had thought. From cream-colored sediments of what was a sea floor 570 million years ago, paleontologists have extracted specimens of 70 species of trilobites, worms, sponges and various ancestors of crustaceans, spiders and insects. They are not only the oldest such fossils ever found but, more remarkably, their soft body parts as well as skeletal and shell remains are unusually well preserved. The fossils give scientists their first glimpse of the strange creatures that populated the seas in the early stage of what is known as the cambrian explosion. The cambrian gelogical period, from 570 million to 500 million years ago saw the appearance of increasingly complex marine animals in a riot of shapes and anatomical designs anticipating much of life as it is today” (snip) Dr Jan Bergstrom, a paleontologist at the Swedish Museum of Natural History…said they suggested that the cambrian transition was ‘a revolution, perhaps more than evolution’. Most of the Chinese fossils, Dr. Bergstrom said, resemble species identified in the Burgess Shale…

(Bergstrom expands on this in his own paper in “Research and Development” (Winter 1991) by pointing out that the Chengjiang fossils are not much different from the Burgess fossils despite their 40 million year difference in time. This is enigmatic, considering the fact that evolution should have been proceeding rapidly during this time, as it apparently had in the preceeding time period.) (snip)

“The similarities (with the Burgess fossils) are the basis for the conclusion that the diversification and proliferation of new life forms must have occurred rapidly at the onset on the cambrian period. “Evolution of these creatures must have been a sudden and widespread phenomenon” Dr. Bergstrom and his colleagues wrote…” (snip) “As the full import of the discovery is recognized, scientists are describing the fossils as ‘genesis material’ and one of the most exciting finds…since the Burgess.” “Dr. Andrew Knoll, a Harvard University expert on early life said: ‘We knew from the Burgess that there was a tremendous diversity of life in the Cambrian. Most of everything that was going to happen, all the ways of making invertebrate animals, had already happened by the mid-cambrian. Now it seems that new life forms were invented within the first few million years of the cambrian.” (snip) “Dr. Bergstrom said it was quite possible that…”you could have the formation of an entirely new type of animal within thousands of years.”

(Or, of course, they certainly could have arrived suddenly on earth from elsewhere…)

These observations certainly appear to me to be incompatible with a darwinian scenario of variation and selection, based on the slow accumulation of beneficial mutations over a long period of time. In fact, it sort of nails the coffin shut on gradualism, which is the foundation of darwinian theory. Clearly, the fossil record falsifies the darwinian paradigm. These discoveries were made 15 years ago. It’s old news. It’s settled, as far as I’m concerned. The only reason it’s still an issue is because so many scientists simply refuse to let go of the darwinian weltanschauung and continually invent new “explanations” and create new obfuscations. Let it go, for god’s sake.

“The real issue is that for a very long period of time there were only unicellular organisms, bacteria, algae, etc. and then at one point in time, somewhere around 600 m.y.a., a great leap foward occurred and multicellular animals made their appearance all at once, and in a very short period of time. All of the invertebrate body plans were ‘found’ if you will, in a period of time that was ‘the blink of an eye’ in evolutionary and geological time. After that time, no new body plans were ever found again. One must wonder why this was so.”

“No new body plans”? I guess it depends on how you define “body plan” because it sure seems to me that nothing like a bird, or a mammal, or a winged insect appeared in the Cambrian. (No flowering plants or for that matter land plants of any kind either, but then the critics of evolution always tend to overlook plants.) And how about Sacculina, a weird parasite with a body plan more like a fungus or an amoeba?

Of course all animals are descended from previously-existing animals–they don’t appear from nowhere–and anything especially new and different (like Sacculina) that evolved after the Cambrian would have evolved from an already-existing phylum and would tend to be pigeonholed in that phylum, no matter how different it was (we can identify Sacculina as a crustacean only because it has a nauplius larva). So I don’t buy the claim that “no new body plans were ever found again.” Sure, the Cambrian “explosion” seems to have been real, so if there are naturalistic explanations that don’t involve mutation and natural selection (with a few jokers like mass extinctions thrown in), let’s hear them.

But nope, “no new body plans”. Keep telling yourself that.

P.S.: we don’t know for a fact that all the phyla or “body plans” originated during the Cambrian “explosion”. For one thing, there are some phyla that make their first appearance in the fossil record well after the Cambrian (like Bryozoa) and numerous others for which we have no fossil record at all.

In addition, it appears that some of the classically-defined phyla–which have been morphologically defined by their “body plans”–are not natural and that some of the traditionally recognized “phyla” are polyphyletic or paraphyletic, and certain phyls have indeed evolved from others at some point after the Cambrian “explosion”.

mrdarwin Wrote:

“No new body plans”? I guess it depends on how you define “body plan” because it sure seems to me that nothing like a bird, or a mammal, or a winged insect appeared in the Cambrian.”

Look for the word “invertebrate” in the second sentence. I think that should diminish your confusion.

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Nobody cares what you think, Charlie. (shrug)

Look for the word “body plan” in a whole bunch of my sentences. You are making a specific claim that “new new body plans were ever found again [after the Cambrian explosion]” and I’m saying your flat-out wrong, unless you define such words as “new”, “body plans”, “ever”, “found”, and “again” in a very specific, very narrow way, and EVEN THEN you’re wrong. I contend that that difference between the modern representatives of the phyla and their earliest ancestors that appeared in the Cambrian “explosion” is huge, and there has been at least as much evolutionary novelty within the phyla as there has been between them; we simply regard the patterns of origin of that novelty differently because we have more direct evidence of it.

“And the oceans…there’s a poser. Conditions on the sea floor are fairly uniform from one place to another…”

Now who’s laughing whose ass off?

(BTW I may be judging you too harshly, maybe you’re making sense somewhere in that mishmash and if so I apologize for my tone but after reading it a couple of times I’m still not entirely sure what you’re saying or what your point is.)

maybe you’re making sense somewhere in that mishmash

no, you got it right. CW is senseless.

go check out his website sometime.

I’ve wondered if anyone has used genetic data to answer questions about last common ancestor issues among invertebrate phyla or would that be considered a waste of time and resources. Would the elapsed time since LCA be so great that any statement based on DNA profile be meaningless. If studies such as these have been done do they fully support the fossil record? I had asked once about using genetic data on reptile relations and I remember a response that the depth of division in time was so great that such data might be meaningless. If so is there a time limit beyond which nothing meaningful can be gained from comparative DNA analysis?

Pete Dunkelberg Wrote:

Note that there are plenty of precursors.

There may be ‘plenty’ of precursors, but not as many as Darwin expected. He expected the pre-Cambrian to be of the same length of geologic time as the Cambrian to the present: viz, ~540 MY. And he expected the pre-Cambrian to be as fully stocked with life forms as from the Cambrian to the present.

No matter how you slice it, what we see in the fossil record cannot be matched up to Darwinian expectations.

Hey, Blast, you’re back! We missed you. Larry Fafarman just doesn’t have your flair, his closet racism aside.

No matter how you slice it, what we see in the fossil record cannot be matched up to Darwinian expectations.

To which I may reply, so f*cking what?

I notice your slyly ambiguous use of the word ‘Darwinian’; I see two meanings here: (a) ‘pertaining to Chas. Darwin’, and (b) a synonym for ‘evolutionary’. You’re technically using it in sense (a), but want people to infer sense (b).

Anyway, are you trying to imply that evolution in 2006 ought to be judged by what Charles Darwin did or did not understand 140 years ago?

Blast writes “There may be ‘plenty’ of precursors, but not as many as Darwin expected. He expected the pre-Cambrian to be of the same length of geologic time as the Cambrian to the present: viz, ~540 MY. And he expected the pre-Cambrian to be as fully stocked with life forms as from the Cambrian to the present.

No matter how you slice it, what we see in the fossil record cannot be matched up to Darwinian expectations”

Modern evolutionary biology is no more beholden to Darwin than modern physics is to Newton.

As usual, you have no argument, just misinformation, halftruths and lies.

Do endeavor to do better. You’re wasting electricity.

Re “and there has been at least as much evolutionary novelty within the phyla as there has been between them;”

Yeah, there’d have to be, wouldn’t there. From what I’ve read on the subject over the last 10 years or so, I’d think that those Cambrian precursors to the modern phyla wouldn’t have been any more different from each other than classes (or maybe orders) are today (i.e., a group of scientists studying them at that time would have called them orders or classes of one phylum).

Henry

I’m new here, but I’m confused by the comment “this is not an event that challenges evolutionary theory, nor should it give comfort to creationists of any stripe.”

I thought evolution was mute on the origin of life. IOW, I didn’t think that design and evolution were mutually exclusive points of view.

Design at some level is a possibility and a plausible hypothesis.

I’m also wondering, as a newbie, what are the laws of evolution? You know what I mean? For example, there’s electromagnetic theory, and the laws of electromagnetism. The laws are those aspects of the theory that have been tested and verifed in the “lab” so to speak and can be used to predict future events.

You’re a bit transparent, Dave. Those are rather poor questions of the sort clueless creationists ask.

I disagree that evolution is mute on the origin of life. There’s a lot of interesting work being done on chemical evolution.

Most importantly, though, the topic here is not about the origin of life. It’s about the Cambrian, when there was a radiation of metazoan life. The origin of life was a few billion years earlier.

The difference between design and evolution is that there is no evidence for design, and there is a lot of evidence for evolution. Design is currently exclusive from science, because it is not based on evidence and observation. You’ll have to do some work to make it scientific, something creationists seem loath to do.

Possibility and plausibility are not sufficient to be scientific.

There are laws of evolution: the Hardy-Weinberg law, for instance. You are being disingenuous, though, and expressing a naive view of science that assumes “laws” are something particularly valued and higher in a hierarchy of ‘truth’. This is another common creationist misinterpretation.

I strongly recommend that you try to learn something about evolution from a biology text rather than your preacher or some creationist website. I’m sure you think you are being clever and cunning, but we’re laughing at you.

Stuart Weinstein Wrote:

Modern evolutionary biology is no more beholden to Darwin than modern physics is to Newton.

As usual, you have no argument, just misinformation, halftruths and lies.

No one is more “Darwinian” than Richard Dawkins. He’s more Darwinian than Thomas Huxley ever was.

Tell me, if you’re not beholden to Darwin, where did the idea of Natural Selection come from?

Arden Chatfield Wrote:

Anyway, are you trying to imply that evolution in 2006 ought to be judged by what Charles Darwin did or did not understand 140 years ago?

The only difference between Darwinism of 1859, and neo-Darwinism of 2006, is that there is a mathematico-genetic sublayer to it. Meaning that Mendelian genetics–with its corpuscular basis–is invoked, and, along with Fisherian mathematics, is used to give the impression that RM+NS can lead to diversity of forms. This is a technical, and, in strictly in terms of theory, a rather minor modification of Darwinism-1859. I’m afraid you’re strapped with a 19th-century scientific theory.

And, BTW, it is a big deal that more forms are not seen in the fossil record since, per Darwin himself, this is dispositive for his theory–no minor detail here.

PZ Myers Wrote:

There are laws of evolution: the Hardy-Weinberg law, for instance.

How ironic that this is the only “law” you invoke since it is a law of ‘stasis’, a law that says alleles are neither created or destroyed from one generation to the other–a seeming hurdle for evolutionary theory.

You don’t seem to understand H-W. It describes the stable state under which there is no selection for a particular allele. It is particularly useful because when we observe deviations from H-W equilibrium, it tells us the population is changing in the frequency of a particular allele.

It does not say that all populations obey the “law” and are therefore static.

Wowzers!.… blisters projects from the past The only difference between DarwinismCreationism of 1859, and neo-DarwinismCreationism of 2006, is that there is a mathematico-genetic sublayer to it. Meaning that MendelianBlastfromthepastian genetics—with its corpuscularsnake toxin basis—is invoked, and, along with Fisherian Dembskian,Sewellian mathematics, is used to give the impression that RM+NS can lead to can NOT lead todiversity of forms. This is a technical, and, in strictly in terms of theory, a rather minor modification of DarwinismCreationism-1859. I’m afraid BLAST you’re strapped with a 19th-century scientificCreationismtheory.

And, BTW, it is a big deal that more forms are not seen in the fossil record since, per Blast himself, this is dispositive for his theory—no minor detail here.

The creationism of 2006 denies most of genetics and uses bogus mathematics, so I don’t think the comparison is exactly parallel.

Also, I failed to mention the biggest error in BlastfromthePast’s comment. The H-W law does not state that alleles can be neither created nor destroyed.

Of course PZ Thats why when Blast projects he includes his one true word of BlastTM version of pseudo_genetic sublayer and we all know that Dembski,Sewell only have pseudo mathematics going for them. Blast already has the answer and it make me wonder why he even bothers to ask. tcht .…of course

The old “I think therefor I am”

“Yet ah! why should they know their fate? Since sorrow never comes too late, And happiness too swiftly flies. Thought would destroy their paradise. No more; where ignorance is bliss, ‘Tis folly to be wise.” –Ode for Music by Thomas Gray

begging the question.

Begging the question does not mean to bring up the question. It means to present as true a premise that requires proof–i.e., taking a conclusion for granted before it is proved or assuming in the premises of your argument what is supposed to be proved in the conclusion. (This fallacy is related to the circular argument.)

Well, I apologize for being OT, but again, what are the major laws of evolution? I’m assuming that this is a no-brainer, but I checked my two college biology texts (good, mainstream texts used in all the universities) and cannot find them.

We have H-W for starters. Are there others?

I appreciate your acknowledgement that design is a possibility. I think its fair to say that design is a valid scientific hypothesis, but that work needs to be done to develop a forensic science that can detect/demonstrate design much the same way that we have forensic science that can conclude that life originated 4 billion years ago.

Umm, I think you missed the intro of this discussion. Arden claimed engineers were more susceptible the wiles of ID than the typical scientists.

and i claimed that to be an overgeneralization, and still do, despite your response.

My comments about the engineering curriculum is that it is packed too full already. Very few students are able to complete it in 4 years. It was *MUCH* harder than any of the science major curricula (chemistry / physics / psychology / computer science) that I had friends or family in. What core content would you cut to provide those classes on critical thinking, logic, or the history of the discovery of all of that material?

Excellent question. I got a degree in computer science back when I was a professional student (because they were handing out fellowships in those days), and at the college I attended (Rochester Institute of Technology), 3/4 of those who started in computer science had either flunked out or changed majors before graduation. It was simply too hard. But then again, it was offered in the engineering school, so the distinction between computer science and engineering might be debatable. I was required to take a minor in discrete math - only introductory differential and integral calculus, but a LOT of group theory, number theory, predicate calculus, abstract algebra, symbolic logic. And this was in addition to all the courses on operating systems, tape transport systems, languages, and the many other computer courses. I was taking 18 credit hours a semester. NOT an easy degree.

And no, there were no courses in the philosophy of science. There weren’t even any required courses in math or computer history. And the degree program required only minimal English or other non-engineering courses. Hell, I fulfilled my foreign language requirement with Fortran!

And despite all this, I think the emphasis being placed on formal education requirements is largely irrelevant. What formal education does is present to the student the sort of material the professor thinks cuts to the chase most efficiently. I always found that I was best off casting around for whatever texts made things must understandable to me. In this sense, the entire academic experience isn’t much more than a motivational engine - it MAKES you read texts and learn the material; it focuses and enforces and organizes your discipline. The material you need is THERE, schools only serve as validation that you looked at it.

The (narrowly specific) field I’m in is not now, and has never been, taught in any schools. And competence in this field places a very heavy requirement on technical history. Most of us doing this are perforce quite old (sad to say).

Anyway, the philosophy of science, and any understanding of the scientific method, and any perspective on what is and is not science, is only partially available through formal education and “book-larnin”. What is mostly required is an active mind and a willingness to use it. Quite a few participants here don’t have the targeted formal education, but are smart and educable anyway, and that’s what matters. And Jonathan Wells or Kurt Wise can get a legitimate PhD from a top school, studying a directly relevant field, without their blinders ever budging.

There’s no magic bullet here, folks.

Flint I agree. I think STJ has placed too much emphasis on getting this taught as education. He might as well say

I’m shocked they don’t teach critical thinking to …education majors …accounting majors …pre-med majors …vet sciences majors …pre-law majors …Starbucks barristas …Walmart greeters …burger flippers

Don’t they realize that *science* provided them with the tools that they need for their trade? Don’t they realize these are valuable skills that would be beneficial to them on a daily basis?

You see STJ, I *do* think they’re valuable. I *wish* they did provide some formal education in my major. Although it would be beneficial to most people to learn this material it just isn’t necessary for them to know on a daily basis.

Furthermore I didn’t *need* it to do my job. In fact I needed it less than all/most of the other technical subjects I took towards my major. I can’t think of anything they should have replaced with it AND I don’t think I could have finished my major in 4 years if it had been added.

I personally did take 2 courses in logic. I also took many (~25 quarter hours) of unnecessary science credits (including chemistry, physics, geology, & geophysics). Just remember they were NOT required, I took them because I like science and the subject matter interested me.

jim:

Interestingly enough, I’ve learned on the After the Bar Closes forum that Sir Toejam is really no different from those he criticizes. He dismisses as ignorant those who know a lot less than he does about his field; he dismisses as incoherent those who know a lot MORE than he does about THEIR field. Outside his specialty, STJ relies on Belief, and defends it the same way any creationist does - with misrepresentation, dismissal, insult, silly claims, the whole nine yards.

So that’s what motivated my post. Ignorance is a policy choice. It’s not a matter of what topics were covered in courses required by the institution granting a degree; it’s a willingness to listen to those whose knowledge trumps your emotional needs. If ignorance is *required* to support those emotional needs, you can defend it pretty easily. Creationists are experts at this. I was surprised to learn that Sir Toejam used creationist tactics to defend his emotional requirements, rather than recognize that they even WERE emotional.

But this shouldn’t be much of a surprise. The creationists have whole books full of quotes of pronouncements from Nobel prize winners pontificating on fields well outside their narrow specialties. Scientists NEVER seem to recognize that expertise in the area of their specialty does NOT imply expertise in areas about which they know nothing. To them, they are EXPERTS.

Personally, I think that if you are open to the idea, you can learn it. If you are not, you can (as Wells and Wise) get a PhD without ever grasping the essence of it. I strongly doubt that a willingness to consider different ideas comes from formal education, nor that any amount of formal education leads to more willingness to consider different ideas. It’s a character trait.

flint:

Bringing in discussions from out of topic threads is pretty underhanded tactics, to say the least.

are you SURE that’s the way you want to play this?

do you want me to go through all of your posts ever made on pt and challenge all of your erroneous conclusions and fallacies?

I kept my discussions of economics confined to that thread. I’m fast losing respect for you as you fail to do the same.

Jim:

you are still quite mistaken in your thinking that you were never taught the scientific method.

defacto, you WERE taught the scientific method when you studied physics, and chemistry, and yes, even mathematics.

whether or not you acknowledge remembering the formal definitions of terms, you literally could not have proceeded in any experimental field of science without it.

my shock is not that you weren’t taught the scientific method, but that you apparently fail to recognize that you were.

like i said, go talk to one of your professors and ask them if THEY think you ever learned the scientific method as an engineering student.

I doubt they would agree with your assessment.

the thought processes that lead to thinking that knowledge of the foundations of science is not necessary to do science eventually becomes the the same as those who no longer think science is necessary at all to progress.

It’s a slippery slope.

Sir Toejam:

do you want me to go through all of your posts ever made on pt and challenge all of your erroneous conclusions and fallacies?

Do you wish to subject your reactions to PT scrutiny? I’m willing…

I kept my discussions of economics confined to that thread. I’m fast losing respect for you as you fail to do the same.

If you discussed economics, I missed it. Despite reading all you wrote, I saw no economics. I saw LOTS of arbitrary statements of preference. Nonetheless, I mentioned no economics here. I mentioned your tactics and your character. I stand by what I wrote. So far, you have earned no respect. You have punted any benefit of the doubt.

jim:

Obviously, if you believe STJ, you are entirely wrong. You MUST be wrong, STJ THINKS so.

Sarcasm off, I agree with you, engineers are taught to apply accepted methods, techniques, and principles to solve problems. Engineers, by implication, are taught to trust that the theoreticians know their jobs, know what they’re talking about, and know that their hypotheses have passed appropriate tests. Advanced engineering degress require that one demonstrate the ability to apply known principles to novel problems - NOT to derive new principles.

But STJ, never having taken an engineering degree and thus abjectly ignorant of what goes on there, seems to have not the slighest problem telling you what your professors *probably think*. His Faith is as impermeable in engineering as it is in economics. You were there, he was not, but he KNOWS that you were “quite mistaken” about your own education.

Gee, that sounds an awful lot like how creationists think.

Sarcasm off, I agree with you, engineers are taught to apply accepted methods, techniques, and principles to solve problems. Engineers, by implication, are taught to trust that the theoreticians know their jobs, know what they’re talking about, and know that their hypotheses have passed appropriate tests. Advanced engineering degress require that one demonstrate the ability to apply known principles to novel problems - NOT to derive new principles.

Well, having taken several years of science and engineering courses at college, I can say that my experience was more like this than anything else. There is a bit of lip service paid to scientific methodology, but the first time I really UNDERSTOOD it was when I was doing graduate studies, and trying to forge a research program for myself.

I think the Salem Hypothesis is a lot closer to reality than some people would like to think.

Ok Flint. gloves are off.

starting next week, i’ll be starting to cross post all of your posts.

have fun. I know i will. hell, i’ve argued with you about genetics and behavior, where you showed how ignorant you were of standard methods in psychology and behavior, so I think I’ll start there.

btw, assuming i don’t have an engineering degree is one thing, but assuming i don’t know any engineering students, professors, or departments is quite another. having spent many years in various universities, one does get a perspective for how different departments approach the teaching of their subject matter. something you too would have gained had you attempted a “classical education”.

btw, where is your engineering degree that allows YOU to pontificate? spent much time at any universities lately?

uh “sarcasm aside”

there is a basic misunderstanding here that the application of the scientific method is ONLY used to derive “new principles” it isn’t.

even in the first part of flint’s sentence:

engineers are taught to apply accepted methods, techniques, and principles to solve problems

he grasps, if only subconsciously, exactly what i was talking about.

you could substitute chemist, biologist, or physicist for engineer here and still be correct.

those accepted methods and techniques and principles don’t exist apart from the methods, techniques, and principles that created them.

If you even took 1 physics class, you ended up learning the scientific method, whether it was presented formally as such or not.

Scientists NEVER seem to recognize that expertise in the area of their specialty does NOT imply expertise in areas about which they know nothing. To them, they are EXPERTS.

I’m surprised that you’d say this, Flint. I think the truth is closer to the contrary - just about everyone who has a strong opinion thinks that theirs is as valid as those of experts in their own field (most especially in terms of constitutional law, I’d say), whereas scientists nearly always defer to experts in fields of science which are not their own.

and flint qualifies himself as an “expert” in economics because he read a few books.

when vehemently challenged on some of his postulations, he decides he needs to find emotional support by dragging the arguments from one thread into another.

so be it.

Interestingly enough, I was required to take a critical thinking course as an engineering undergrad. The course was called Creative Problem Solving, and I use the concepts taught in that course more than any other individual engineering course I took. Frankly, it was my favorite course, and I think it would translate into a high school course quite easily.

The engineering courses I took were heavily based on the scientific method. In large part, it was because of the high emphasis on lab-based learning. The lectures may have taught us the science that brought us the concepts, but the in the labs, welearned the scientific method and the critical thinking skills needed to be a top engineer. Every class had a lab; one quarter, I was required to spend a minimum of 21 hours a week in lab!

And it was the skills that I earned from that grueling lab schedule that make me such a valuable asset to my company. One of our clients is the public electric utility for one of the ten largest cities in the US. The day after the 4th of July weekend, I received an urgent call: the system I had recently done some work on was malfunctioning, and I had 6 hours to find and fix the problem or they wouldn’t be able to provide enough power to the city. Within two hours, I had isolated the problem and was able to offer 3 courses of action, including an emergency bypass that could be instituted with a single wire and one minute of labor. With well over 3 hours left, that enabled us to examine the components without fear of being forced to shut down, and after an hour of testing discovered the cause of the problem (the holiday crew had shut off the wrong valve!) But if I hadn’t taken all those labs and thus had ingrained in my brain an efficient method of analyzing data, we would not have been able to figure out what had happened in time.

Sure you can be an engineer without a strong grounding in the scientific method. But you can’t be the kind of engineer I am.

you could substitute chemist, biologist, or physicist for engineer here and still be correct. those accepted methods and techniques and principles don’t exist apart from the methods, techniques, and principles that created them. If you even took 1 physics class, you ended up learning the scientific method, whether it was presented formally as such or not.

Hrm. Didn’t take a lot of classes with premeds, did you?

I will respectfully disagree. Does the phrase “know the words, but not the music” mean anything to you?

argy stokes:

You’re correct, and my apologies. SOME scientists consider themselves generic experts (see Sir Toejam for example) but others are very careful to recognize that they do not know what they do not know.

It seems that engineering degrees offer amazingly wildly different curricula. Some programs seem to insist on extensive “philosoph of science” background material, some offer it as an elective, some omit it altogther.

Sir Toejam:

I said I’d studied the subject. I did. You said you did NOT study the subject. I admit I have NOT studied anything in YOUR specialty. Now you propose to demonstrate that everything I post is incorrect in EVERY area, your own personal knowlege notwithstanding. You’re right in YOUR field, you’re right in MY field, you’re right in YOUR profession, you’re right in MY profession, you’re always right. Good for you. Must be nice.

I hope while you’re at it you show how much righter you are than jim, kevin, gwangun, and everyone else who has direct experience you lack (but which doesn’t slow you down any more than any other creationist). I’m sure that will make you feel really really good.

Jerk.

MrDarwin Wrote:

Does anybody else besides me think that everybody is being awfully hard on Dave? It doesn’t’t matter if he’s trolling or not, it’s possible to answer his questions and point out some problems with his premises—which others who are lurking may share—without being abusive (as Flint was able to do pretty thoroughly).

Yes. Rants often seem “designed” to obscure the ignorance of the poster, it’s a shame when people (I’m sure it’s out of genuine exasperation) fall into this counterproductive mode too quickly. Mind you, Mr Fafarman, for example, has used up all his consideration credits.

Maybe you are not fully across the thread. Check this gem from Dave further up:

Folks - presenting me with a large number of reference sources is appreciated, but you are confusing quantity with quality. And please don’t waste my time with talkorigins. (Some of the other references are quite good, and I do read those)

If the guy would categorically dismiss talkorigin as time wasting, he really does not deserve our respect.

Hadn’t read to the end when added previous post. Might still have some relevance. What do you think, Sir T?

All right, I confess, there ARE some good materials at talkorigins. But, talkorigins is at its heart propaganda, and very intolerant to dissent. I prefer to support web sites that are more objective and perhaps humble in their advocacy or presentation. Brow beating is brow beating whether it comes from an religious zeolot or an evolutionary zeolot. The religious zeolot says if I don’t believe, I’m going to burn in hell. The evolutionary zeolot says if I don’t believe, I’m threatening the future of society and that I’m evil.

You may have noticed, I’m not a big fan of totalitarian methods, and that’s essentially what you’ll find at talkorigins and to some extent, PT.

I’m still interested in discovering the laws or postulates of evolution, particularly those that spell out the rate at which genetic mutations spread throughout a population. Then, i’d like to understand specific sequences of mutations that science has either reverse engineered or replicated in the lab that demonstrate the creative power of RMNS, as well as the time required for significant biological change to occur and spread. You’d think that would be Evo101, but for some reason, its just not covered. I found some good information on this in a book by Lee Spetner, “Not By Chance.”

Scientists NEVER seem to recognize that expertise in the area of their specialty does NOT imply expertise in areas about which they know nothing. To them, they are EXPERTS.

I’m surprised that you’d say this, Flint. I think the truth is closer to the contrary - just about everyone who has a strong opinion thinks that theirs is as valid as those of experts in their own field (most especially in terms of constitutional law, I’d say), whereas scientists nearly always defer to experts in fields of science which are not their own.

Actually, I have to agree with Flint here. I’m in linguistics, and I’ve long since noticed that there’s a phenomenon where specialists in all sorts of fields occasionally wander into linguistics with zero training, convinced that their natural intelligence and training in genetics, math, computer science, or philosophy qualify them to do linguistics at least as well as anyone with a PhD in the subject. What they usually end up doing is writing non-peer reviewed books or popular science articles either showing how all previous linguists have gotten the questions completely wrong, or coming up with spectacular new conclusions unlike anything anyone’s ever thought of. (Historical linguistics seems to be especially vulnerable to this.) And I would say about 99.9% of the time, the resultant work is basically useless – the arguments are completely absurd, with extremely basic errors, both in data and methodology, which render the work meaningless.

It’s not too different from when some property manager or retiree decides to revolutionize quantum physics, or when someone with a degree in math or electrical engineering decides to write a book explaining why evolutionary biology is completely wrong.

Perhaps linguistics is especially prone to this since people view it as a ‘soft’ science; so your average, say, physics PhD assumes it must be very easy and all it would take to revolutionize it and do it better would be just being smart. Maybe the assumption is since everyone uses language, anyone can write analyze it.

STJ,

I never said that I had never been taught (or didn’t understand) the scientific method. I said it was not part of my engineering curriculum.

In fact, I had a wonderful AP chem teacher in high school. This was a guy that earned a BS & MS in chemistry, went and worked in industry for over a decade, and decided he didn’t like it. So he went back for his secondary education degree and taught HS chemistry.

2 of my siblings went into chemistry because of him. I personally took lots of unnecessary college level chemistry because of how much he influenced me.

I’d rank him as #2 of my all time favorite teachers (reserving #1 for a college professor I had).

That sort of teacher is something that every child should get at least once during their school years. If more students did get teachers like him, I can guarantee more kids would go into the sciences!

Anyway, he spent a great deal of effort teaching us not only chemistry but a great deal of the underpinnings of science in general, including the scientific method.

However, the only class I can think of that included any indirect teaching of critical thinking was my HS senior government class. We held 2 mock trials. In the first (which was held in our classroom and various students performed the different roles in a trial), I performed as an attorney. That was an excellent exercise in critical thinking.

The second mock trial we participated in was held by the University of Dayton Law School. We served as jurors for their mock trial. 3rd year law students served as attorneys, a real attorney served as a judge. We even got to use a real courtroom. That was a real cool experience!

IMO the subject most likely to teach critical thinking thought process would be debate. I never took debate, but now wish that I had.

******************

FYI, perhaps a lot of the disagreement here comes from using the same words but meaning different things.

For instance, when I say “critical thinking” I am not referring to problem solving capabilities. I am specifically referring to the capacity of dissecting what’s being said/written for it’s true content (if any) and comparing that content to other pieces of information. Then if correlated positively, using that information to help build a bigger picture. If correlated negatively, trying to unravel what was said for other clues towards what else might be false or what the motives of the speaker/writer were.

In essence, my “critical thinking” would be highly valuable in for instance a debate or a trial.

When I say we didn’t learn “the scientific method”, I’m saying that we did *NOT* learn troubleshooting skills. Tests, quizzes, & homework were nearly always basic application of the materials discussed in classes. We had very few labs. The best exposure I got to this was in our NASA sponsored design projects in which we solved a variety of problems. However, the problems we solved were not typically of the “troubleshooting” variety.

A good example of the above was I was tasked to design tubing to get viscous liquid metal from a furnace to a piezoelectric nozzle with out overloading the piston that pushed it out of the furnace (this was to be an experiment carried on the space shuttle). I struggled with this problem for weeks because although I had access to all of the formulas required to figure out how much back pressure would be generated for a certain diameter, length, and bend of tubing AND I had access to the information about the pressure the piston could exert, I did not have the ability to optimize the equations to figure out the minimum tubing requirements.

My final solution was I worked the problem backwards. I first figured out the maximum bend curvature & diameter and minimum length of tubing I could accommodate in the space provided and then see if the resultant back pressure was low enough for the piston. Turns out it was. So I submitted this design. Not the most elegant approach to the solution BUT it was very practical.

I also took both introduction to logic and symbolic logic. The latter was very useful for both developing the system of problem solving that I use now (typically a binary tree approach) but is somewhat useful in analyzing statements for logical inconsistencies. In general the logic that I had doesn’t help me as much as it should with the spoken word but it helps a lot in other situations.

Dave,

I’m a Rocket Scientist but not a biologist, say take what I say on this with a hunk of salt.

Regarding the reconstruction of mutations. Look at TalkOrigins for a paper on the gene mutations involved in the making of vitamin C in humans and chimps.

Note, I don’t think scientists are at the point of “making” new mutations intentionally. Although we can induce mutations, it’s more random that “engineering”.

Also note, I don’t think this is on TalkOrigins, but I remember reading a paper about “designing” a bacterium to have the fewest number of genes possible. Others here could probably discuss this research in some detail.

Regarding TalkOrigins being propaganda… If you mean that in the sense that it’s supposed to be a tool used by scientists to sway public opinion, then yes you’re right.

If you mean that they’ll say anything in order to sway public opinion whether it’s right or not, then no you’re wrong.

As far as my knowledge goes, everything I’ve seen at TalkOrigins is TRUE. If you find errors, please provide the admins there with feedback pointing it out with references to back your claim. I have *seen* them make corrections when errors have been pointed out. Be aware, that using quotes from Dembski, Behe, Johnson, et al saying that something is wrong at TalkOrigins just won’t cut it. You’ll have to find primary resources that rebate the information there.

err, change “that rebate the information there” to “with the correct information”.

I have no f**king idea where that phrase came from…

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This page contains a single entry by PZ Myers published on December 30, 2005 2:16 PM.

Don Wise and Incompetent Design was the previous entry in this blog.

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