Freethought & Rationalism Archive

Ed · 04-16-2002, 07:54 PM

Quote:

Originally posted by Oolon Colluphid:

Originally posted by Ed:
lp: Ed, do you have any good reason for that being the case? Though some noncoding DNA is probably involved in gene regulation, much of it is just plain junk.

Ed:How can you be so certain? Great scientists of the past showed more humility. They would say "that at present it appears to have no function."

OC: That is quite ridiculous. There has been a hell of a lot of research into this stuff, and none of it suggests functionality. Some of it we can be extremely certain about: satellite DNA, for instance, is tiny pieces, just a few base pairs long, that do not code for anything, and that are repeated millions of times. It’s not just that it lacks ‘start’ and ‘stop’ codons: it ‘reads’ as nonsense even if it were read. In Drosophila, just three bits of satellite DNA seven bp long make up 40% of the entire genome.

Sure, it might have a function. But despite all the research and all we know about genome function, it really really doesn’t seem to. It is perfectly possible that it doesn’t have one, and we have good ideas about how it came to be. In the absence of a single scrap of evidence suggesting a function, the only option -- for now -- is to say that it doesn’t have one. It is possible that it might. But it doesn’t seem to. It is also possible that there are fairies at the bottom of gardens throughout the world. But in the absence of credible evidence for them, we are safest assuming there are not. We’ve looked, we’ve tried really hard, and there ain’t. Therefore the burden of proof is now on those who propose the existence of fairies -- or of functions for junk DNA. IOW, you think it has (as yet unknown) functions: you show us why you think so.[/b]

See above, I didnt say that it all once had a function.

[b]

Quote:

Ed: No, the Piltdown fraud was perpetrated by evolutionary scientists and as I stated above the Paluxy tracks were carved by local pranksters not creation scientists. That is a pretty significant difference.

OC: Ed, get over it. Piltdown was controversial even in its time. Its time has long past. Piltdown is irrelevant to our modern understanding of human evolution. I refer you back to my points and questions above, as yet unanswered. Of course scientists, being human, make mistakes, and a few may even make up data. But they will be found out. It was scientists, not creationists, who confirmed Piltdown as a hoax. It was scientists, not creationists, who confirmed Archaeoraptor as a hoax -- though the two fossils it was made from turned out, individually, to further support evolution. And it was scientists, not creationists, who showed the Paluxy tracks to be a hoax. Are you saying that, whoever made them, they were not taken up with glee by creationists? Science is self-correcting; creationism refuses to budge regardless of evidence.

Now please answer my questions.

TTFN, Oolon

Yes, they were happily taken up by creation scientists. Both evolutionists and creationists are self correcting but only up to a point. Would evolutionists ever give up the flawed philosophy of naturalism? I seriously doubt it.

Ed · 04-16-2002, 08:03 PM

Quote:

Originally posted by ps418:


Denton goes even further in his comment on the Phillip Johnson/ Denis Lamaeoreax "debate," in Darwinsim Defeated? The text below is from a previous post:

Michael Denton comes out even more forcefully for CD. Actually I wish Johnson's worthless rebuttals had been ommitted to make more room for Denton or Miller or anyone else who, unlike Johnson, was prepared to discuss "detailed evidentiary issues." Denton strongly criticizes Johnson's use of gaps in the paleontological record as evidence against descent with modification. He writes:

To a very large extent the arguments of Johnson, and indeed of special creationism throughout the past 150 years, depend critically on the claim that the gaps between the different groups of organisms are absolute, could not have been closed via a series of functional intermediates, and are prima facie evidence against common descent and can be taken as evidence for divine intervention.

A primary problem with this strategy is obviously, How can we be absolutely sure that the gaps are as real as they appear? If there is even the slightest room for doubt, the whole strategem collapses. And one reason for doubt is . . . that gaps that once seemed unbridgable have been closed as knowledge has advanced. . . p.143

Denton also briefly discusses biogeographic evidence, and how impotent special creation is to explain any of the data in this field. One example he discusses is the concordance of divergence ages estimated from molecular evidence and divergence ages as estimated from geologic evidence. Discussing Gondwana, Denton states:

The relative implausibility of the creationist model grows further when we examine the DNA sequences of the modern descendents of the ancient fauna and flora of the supercontinent. What we find is fantastically difficult to account for on creationist terms. By comparing the DNA of the various related species stranded in Australia, South America, and Africa as Gondwanaland fragmented, and extrapolating backwards using molecular clock estimates to the time when the sequences converge into ancestral sequences, we get a date of approximately 100 million years . . much the same date that we derive from geological and geophysical evidence for the initial splitting of the supercontinent.

Denton concludes his bried discussion of biogeography, saying:

I think that in the face of the facts of geographical distribution, the inference to descent with modification is inescapable, and I suggest that if indeed special creation is true, then it is evident that God must have created life to appear as if evo9lution had occurred. p.149

[ April 05, 2002: Message edited by: ps418 ]

EDIT: To add another quote from Denton's Nature's Destiny:

"One of the most surprising discoveries which has arisen from DNA sequencing has been the remarkable finding that the genomes of all organisms are clustered very close together in a tiny region of DNA sequence space forming a tree of related sequences that can all be interconverted via a series of tiny incremental natural steps".

"So the sharp discontinuities, referred to above, between different organs and adaptations and different types of organisms, which have been the bedrock of antievolutionary arguments for the past century (3), have now greatly diminished at the DNA level. Organisms which seem very different at a morphological level can be very close together at the DNA level" (p. 276).

[ April 05, 2002: Message edited by: ps418 ]

Again his present evolutionary beliefs are irrelevant to the evidence that he presented in his book, most of which still stands against Darwinian evolution. Also, in one his statements you quoted above he talks about ancestral DNA sequences. There is no such thing for most organisms that lived at the time of Gondwanaland. So I acknowledge that even Michael Denton makes mistakes.

Ed · 04-16-2002, 08:05 PM

Quote:

Originally posted by ps418:
Ed:
Who said anything about a 6000-10,000 year old geology? We don't know when the flood was, it may have been a million years ago.

We dont know when the flood was? Perhaps you could explain why you believe this, and why the following analysis is (potentially) wrong by many orders of magnitiude:

I Kings 6:1 says that 480 years passed from the start of the Exodus to the start of construction on the first temple by Solomon. Gal 3:17 says that 430 years passed from the covenant with Abraham to the delivery of the Law to Moses. Yahweh establishes the covenant with Abram about 135 years after he was born (11:32, 26). Abram was born when Terah was 70 (11:26). Terah was born when Nahor was 29 (11:24). Nahor was born when Serug was 30 (11:22). Serug was born when Re'u was 30 (11:20). Re'u was born when Peleg was 30 (11:18). Peleg was born when Eber is 34 (11:16). Eber was born when Shelah was 30 (11:14). Shelah was born from a 35 year-old Arpach'shad (11:12). Arpach'shad was born from Shem 2 years after the flood (11:10).

Since the date of Solomon's reign is agreed to be about 950[+/- 50]BCE, we can calculate the time of the flood using this chronology. Starting with Solomon and working backward, we have:

950BCE +480 +430 +135 +70 +29 +30 +30 +30 +34 +30 +35 +2= 2285BCE

Where does this analysis, which would seem to constrain the flood to a definite historical period about 4300yrs ago, go wrong? Where could that million years be 'hiding'?

I already dealt with this back on pages 1-3.

MrDarwin · 04-17-2002, 05:17 AM

Quote:

Originally posted by Ed:


Yes, they were happily taken up by creation scientists. Both evolutionists and creationists are self correcting but only up to a point. Would evolutionists ever give up the flawed philosophy of naturalism? I seriously doubt it.

It's quite possible that we won't. Bear in mind that just because something has not been explained naturalistically, does not necessarily mean it can not be, or will not be. Can you suggest anything that might persuade us to abandon naturalism? (I can think of several, but I'd like to hear from you first.)

lpetrich · 04-17-2002, 11:22 AM

Quote:

lp: Which is a dumb decision; an omnipotent, omniscient being ought to be aware that there will be some who want a reasonable degree of precision and not hand-waving.
Ed:
Most ordinary people are not ultra skeptical like atheists. So there is no real reason to go overboard on genealogies. Genealogies are not that important.

That is a very lame argument. Genealogies do NOT make for very dramatic reading, which suggests that they are present because they have some purpose. It's just like how much disk space your files consume; that's usually not considered interesting in itself, but an indicator of how much room is left on your disks.

Thus, one reasonably concludes that all those Biblical begots are important in some way, perhaps to demonstrate legitimacy by descent from some appropriate ancestor. The two genealogies of Joseph fit this pattern well, because they aim at demonstrating what great ancestors Jesus Christ had had, though we are also told that Joseph was reproductively cuckolded by Mr. G.

So waving them away is unreasonable.

Quote:

lp: Which leads to the question of what would *not* be an example of such an event.
Ed:
Any event that can reasonably be explained by natural laws or human design and activities. As shown in the scriptures 99.9% of events are not supernatural.

I've yet to see any such claim in the Bible, let alone a clear conception of natural law.

Quote:

Ed:
Well a god that was not invented by men is not going to do things that we think he ought to do.
lp: An ingenious, all-purpose excuse.
Ed:
Nevertheless, a logical conclusion.

Thus making it a hypothesis that can explain anything, and thus really nothing.

Quote:

lp: (how the Egyptian Book of the Dead states that one ought to assert that one has not committed various sorts of mischief...)
Ed:
Egyptian religion does not treat women as well as Christianity does.

Ingenious comeback. It must be embarrassing to discover that other societies have "real" moral codes.

Also, Pharaonic Egyptian religion had female as well as male priests, which is more than could be said of nearly all of Christianity until recent decades.

Quote:

LP: (gene duplication: two dogs, one who chases cats and one who chases squirrels...)
Ed:
No, your genes are not specific enough they dont carry enough information. You have to specify that there are two dogs or that there was a sequence in time. Then the cat then the squirrel etc.

The specification of two dogs is directly analogous to a gene duplication (one -> two).

Quote:

lp: How is DNA supposed to have a "languagelike" code?
Ed:
The genetic code is composed of letters (nucleotides), words (codons or triplets), sentences(genes), paragraphs(operons), chapters(chromosomes), and books(living organisms).

Nice analogy, but it's only an analogy, and it does not prove that it was "designed" by anything. One can find other such hierarchies of structure in various other systems.

Quote:

lp: And as Michael Turton will tell you, archeologists don't work that way. They don't have some criterion for separating designed from non-designed objects; they instead try to consider if some object could reasonably have been made by human beings.
Ed:
I don't see any difference. How do you tell if something has been made by humans? I.e. how do you tell the difference between an arrowhead shaped rock and an arrowhead?

I'm not familiar with this subject, but the trick is to see if it shows evidence of having been shaped in some systematic way, some way that natural erosion would not produce. This means being hit with another rock in certain places and stuff like that.

Quote:

Ed:
Some fish are very sensitive to water hardness, so possibly in the past other organisms were more sensitive to their environment but later on they microevolved "toughness".

It's salinity levels, not mineral content, but the principle is correct. However, these changes in salinity tolerance are proposed on purely ad hoc grounds, to somehow "explain" why the fish survived Noah's Flood.

Quote:

Ed:
I don't consider when the flood occurred a critical question. I consider whether the Christian God exists much more critical, then everything else will eventually fall in place. How come the theory of evolution is unfalsifiable?

But why are you advocating the occurrence of a planetwide flood? And accepting the existence of the Christian God does NOT make everything fall into place -- consider the numerous sects that Christianity is divided into.

Quote:

Ed:
It is not an evasion. I have not decided when the flood occurred, I am waiting for more biblical and scientific evidence. What is wrong with that?
Especially since I dont consider it a very important issue.

But why are you making a big issue out of that supposed flood, Ed?

Quote:

Ed:
Have you read any of Dembski? He uses the SETI program in his book "Intelligent Design" as an example of specified complexity. ...
lp: However, that concept is never used by any mainstream SETI researcher. Can you explain why it seems to be useless to them?
Ed:
Though they may not call it that, they nevertheless DO use the concept. Otherwise they would not be able to separate background noise from a message from ET.

I'm somewhat familiar with the SETI concept, and "specified complexity" is not used anywhere. Instead, the SETI guys ask what an artificial radio signal might look like and what a non-artificial radio signal would look like. Natural radio sources are all broadband, while artificial ones are often narrowband (<~ 1 Hz for TV carrier waves, IIRC; the broadcast content takes up a few MHz). Thus, SETI has focused on detecting narrowband signals.

Furthermore, the question of artificiality has led to numerous controversies in astronomy.

The first pulsar discovered was called LGM-1 at first, out of the hypothesis that "little green men" were running a radio beacon. But since then, a more plausible hypothesis has emerged: that pulsars are rotating neutron stars.

The "canals" of Mars got called that as a result of a mistranslation of Schiaparelli's observation of "canali", which means something like "channels" in Italian. However, to English-speakers, "canal" suggests something artificial, and some astronomers, like Percival Lowell, worked out in detail why he thought the Martians were building them -- as giant irrigation ditches, with what we see being a strip of irrigated cropland. But when spacecraft were sent to Mars, it turned out that these "canals" or "channels" did not exist -- they were the result of connect-the-dot perception by some observers of Mars. But by no means all; some had claimed that they could never see the "canals".

More recently, there has been an abundance of controversy over the "Mars Face", which is real, but which is more likely a byproduct of erosion.

Quote:

LP on Ed invoking the big-sediment view of Noah's Flood.
Ed:
I have not decided on which view of the flood is correct. And I don't consider it of extreme importance.

But why are you making an issue out of it?

Quote:

LP: what mutation saturation is...
Ed:
The genome reaches a point where mutations no longer are able to occur therefore evolution no longer occurs for the organism. This shows that there are limits to biological variation. Which is what creation predicts and these limits produce the "kinds".

Mutations can always occur, and the genome can do a random walk in sequence space.

Quote:

Ed:
Read Michael Denton's "Evolution:A Theory in Crisis" for some of the problems in that area.
lp: Which has some serious misunderstandings of molecular-evolution research.
Ed:
Be specific.

Michael Denton later conceded that he had misunderstood molecular-evolution family trees; he had been perplexed over them in Evolution: A Theory in Crisis.

In particular, he misunderstood how "more evolved" and "less evolved" species can have the same amount of genetic distance from their common ancestor. This is because the molecules often used were under the same selection pressures for all the different ancestors, meaning that all the mutations would be selected from the same OK subset. This means an approximately constant rate of accepted mutations, which means equal sequence distances.

This is actually something of an ideal case; rates of molecular evolution do vary, but they can be calibrated by comparing to the fossil record.

Quote:

lp: Because of being incorporated into the genome of some ancestor of both those species. Ed, I'd be surprised if you really understood that article; such incorporated viruses can be used to work out evolutionary family trees -- which agree with those worked out from other sources.
Ed:
I have no problem with ancestral species. The family trees are highly speculative however.

What makes such family trees "highly speculative"?

Quote:

Ed:
Its called research, we need more of it. ...
lp:
Actually, there has been an abundance of paleoecological research; just consult the professional literature.
Ed:
We will need more than just an abundance.
lp: And what, specifically, will we need?
Ed:
Probably 100 years of intensive research.

Which will likely end up rediscovering what the mainstream scientific community has discovered.

Quote:

Ed:
No, the Piltdown fraud was perpetrated by evolutionary scientists ...
lp: Who? Be specific. This is a very serious accusation.
Ed:
Some (Gould and Leakey) think it was Teilhard de Chardin.

Possibly as a practical joke. However, TdC is not every paleoanthropologist, let alone every evolutionary biologist.

Quote:

Ed:
... Would evolutionists ever give up the flawed philosophy of naturalism? I seriously doubt it.

Why is it supposed to be flawed?

Quote:

Ed:
Again his present evolutionary beliefs are irrelevant to the evidence that he presented in his book, most of which still stands against Darwinian evolution. Also, in one his statements you quoted above he talks about ancestral DNA sequences. There is no such thing for most organisms that lived at the time of Gondwanaland. So I acknowledge that even Michael Denton makes mistakes.

So what do you think had happened to MD's views? Also, what MD seems to be proposing is some sort of vitalistic force that drives evolution.

And did organisms which lived in Gondwana have no DNA?

Quote:

ps418 adding up the Biblical begots:
Where does this analysis, which would seem to constrain the flood to a definite historical period about 4300yrs ago, go wrong? Where could that million years be 'hiding'?
Ed:
I already dealt with this back on pages 1-3.

By supposing that the genealogies had skipped over several intermediate ancestors -- which would appear to be the large majority of them if Noah's Flood had been a million years ago.

[ April 17, 2002: Message edited by: lpetrich ]

Ed · 04-17-2002, 07:46 PM

Quote:

Originally posted by unworthyone:

Originally posted by ps418:
Where could that million years be 'hiding'?

Maybe between verses 1 and 2? [/b]

Hello unworthyone. Maybe so.

[b]

Quote:

Genesis
1:1 In the beginning God created the heaven and the earth.
1:2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.

I mean where did the water come from? It means it was there before he decided to change Earth.

Yes.

Ed · 04-17-2002, 07:50 PM

Quote:

Originally posted by MrDarwin:


So you believe that the fossil strata in question were laid down before the flood, and were essentially unchanged and undisturbed by the flood?

Depending on which flood model, it could be that almost all the strata was laid down by the flood or almost none of it.

Ed · 04-17-2002, 08:19 PM

Quote:

Originally posted by lpetrich:

Ed:
Most paleontologists believe they were slow-footed and slow witted. Only a few would be swept into higher sediments and with such a small number fossilization is unlikely.

lp: WHICH paleontologists?[/b]

Most all paleontologists.

Quote:

Ed:
The independent evidence is the sediments of any large flood even occuring today. If you take samples of the sediment you will see that organisms that are slower and lower in the topography are the ones that are lower in the sediments.

lp: However, floods have a tendency to mix things up -- and not produce the neat layering and alternations of different sorts of rocks that one finds.

I think some hydrologists would disagree with you on that.

Quote:

(Big-sediment vs. little-sediment alternatives of Noah's Flood)
Ed:
There are christian geologists on both sides of the issue. I have yet to decide on my position.

lp: Ed, be honest and take responsibility for your statements. If you defend a position, you are legitimately presumed to be supporting it. So don't turn around and claim that it's not really your position. People will start to question your honesty.

I think I have defended both views. But I am being honest by telling you I am undecided on which view is correct.

Quote:

lp: And why not consider the position that Noah's Flood is pure mythology?

Because it is written as historical narrative and according to the grammatico-historical hermeneutic such stories are meant to be taken literally.

Quote:

lp: Ed, the mainstream scientific community dumped Flood Geology almost 200 years ago, around when Charles Darwin was born. The rocks are too neatly layered to be the result of a single big flood -- especially one stirred up by some Fountains of the Deep.
Ed:
The fountains of the deep were widely dispersed so their effect on the strata would have been negligible.

lp: Which is pure hokum. Ed, which position are you now taking? Big sediment or little sediment?

Both.

Quote:

lp: And why would a virus insert itself into exactly the same place in different genomes? That asks too much of coincidence.
Ed:
Viruses often have the same effect on two different species.

lp: Disease symptoms != insertion locations in genomes.

Yes, generally that is true.

Quote:

Ed:
Hello Cora. Maybe cycads preferred the lower elevation swamps.
lp:
Ed grasps at straws. Present-day cycads don't have such a preference.
Ed:
Well maybe they did in the past.

lp: Ed, maybe Jesus Christ had been homosexual, he with his 12 male Apostles and his beloved male disciple and he and Judas kissing and all.

There is evidence that points to ancient cycads preferring high moisture habitats which is characteristic of low elevation wetlands. So there is evidence for my contention and none for Jesus being homosexual. Kissing was a standard greeting in the ancient middle east and even still today in some areas. Aren't you being a little ethnocentric?

Quote:

Ed:
If human populations were very small during the Cretaceous then there would probably not be any human fossils from that period.

lp: If there were any such populations in the first place.

True.

[b]

Quote:

Originally posted by Duck of Death:
Aren't you YEC? Surely that means that you don't even accept that the Cretaceous period (144-65 mya) even existed! And even if you abandon YEC, you're surely not suggesting that Noah lived over 65 mya?
Ed:
Hello Duck. I am undecided on the age of the earth, but given that the scriptures dont tell us when Noah lived, he could have lived 65 mya.

lp: Very ingenious. Ed jumps between young-earthism and old-earthism as it suits him.

No, see my posts above. I don't claim to know all the answers, why ridicule me for that?

lpetrich · 04-18-2002, 01:49 AM

Quote:

Ed:
Genesis
1:1 In the beginning God created the heaven and the earth.
1:2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.

An alternate translation, with somewhat different Hebrew vowels:

In the beginning of God's creating the heaven and the earth, the earth was without form and void ...

The text flows more smoothly in this version.

Quote:

Originally posted by MrDarwin:
So you believe that the fossil strata in question were laid down before the flood, and were essentially unchanged and undisturbed by the flood?
Ed:
Depending on which flood model, it could be that almost all the strata was laid down by the flood or almost none of it.

Big-sediment vs. little-sediment, as it were. A real scientist would try to decide which one, if either of them, is right; Ed instead prefers to use these possibilities to evade criticism.

Thus, when challenged on the big-sediment hypothesis, he waves around the little-sediment hypothesis, and when challenged on that hypothesis, he claims that Noah's Flood is somehow not an important issue. Which is totally dishonest when one examines the verbiage he has spouted on the Noah's Flood question, especially his seeming advocacy of the big-sediment hypothesis.

Quote:

About trilobites....
Ed:
Most paleontologists believe they were slow-footed and slow witted. Only a few would be swept into higher sediments and with such a small number fossilization is unlikely.

lp: WHICH paleontologists?
Ed:
Most all paleontologists.

Says who? I've recently consulted some sites on trilobites, and they claim no such thing.

Quote:

lp: However, floods have a tendency to mix things up -- and not produce the neat layering and alternations of different sorts of rocks that one finds.
Ed:
I think some hydrologists would disagree with you on that.

However, many places contain alternations of coarse-grained and fine-grained rock, when after a big flood, the coarse-grained sediment would settle first, and then the fine-grained sediment.

Quote:

Ed:
I think I have defended both views. But I am being honest by telling you I am undecided on which view is correct.

Admit it, Ed, if those are views you are not really convinced of, why are you defending them? Furthermore, they contradict each other; contradictory statements cannot be true at the same time.

Quote:

lp: And why not consider the position that Noah's Flood is pure mythology?
Ed:
Because it is written as historical narrative and according to the grammatico-historical hermeneutic such stories are meant to be taken literally.

And how was that figured out? Show the details of this derivation. A real scientist would not hide details of his/her work.

Quote:

lp: Which is pure hokum. Ed, which position are you now taking? Big sediment or little sediment?
Ed:
Both.

Which contradict each other.

Quote:

Ed:
Hello Cora. Maybe cycads preferred the lower elevation swamps.
...
lp: Ed, maybe Jesus Christ had been homosexual, he with his 12 male Apostles and his beloved male disciple and he and Judas kissing and all.
Ed:
There is evidence that points to ancient cycads preferring high moisture habitats which is characteristic of low elevation wetlands. So there is evidence for my contention and none for Jesus being homosexual. Kissing was a standard greeting in the ancient middle east and even still today in some areas. Aren't you being a little ethnocentric?

Ed ought to present his evidence that cycads had preferred such habitats in the past.

And I was presenting that JC-was-homosexual possibility to get you to think about how you endlessly toss out ad hoc hypotheses, O Ed.

Quote:

Ed:
... I don't claim to know all the answers, why ridicule me for that?

Although that is commendable humility, that's not the point.

The point, Ed, is that you keep on jumping around from hypothesis to hypothesis as if you are trying to evade criticism, rather than indulge in serious scholarship.

Oolon Colluphid · 04-18-2002, 03:37 AM

Quote:

About trilobites....

Ed: Most paleontologists believe they were slow-footed and slow witted. Only a few would be swept into higher sediments and with such a small number fossilization is unlikely.

lp: WHICH paleontologists?

Ed: Most all paleontologists.

lp: Says who? I've recently consulted some sites on trilobites, and they claim no such thing.

lpetrich is correct. Trilobites were pretty magnificent creatures. No such claims are likely, because they're pointless. "Slow-footed" is irrelevant for swimmers; "slow witted" is meaningless in this context. Tubeworms are presumably dimmer than trilobites, yet we find their fossils much later ('higher'), and still have them today. (And they are rather bound to be slower footed

) Angiosperms are even slower witted, yet we don't find any before the late Jurassic.

More to the point, many trilobites were bottom-dwellers (some even eyeless burrowers, eg Cryptolithus), but many were open-ocean swimmers, eg Opipeuter. How did they all, whether free-swimming or burrowing in mud, all end up in the same strata (ie none later than the upper Permian)? The bottom-dwellers should always be found in 'earlier' strata, shouldn�t they Ed? Since they weren't adapted to swimming, how did they get higher than many free-swimming ones?

I suggest you have a look round <a href="http://www.aloha.net/~smgon/ordersoftrilobites.htm" target="_blank">this trilobite site</a>.

And talking trilobites, how about the gradual changes Peter Sheldon found in pygideal rib numbers in Ordovician trilobites? From Clarkson (1998):

Quote:

Ordovician (Llandeilian) trilobites in Central Wales occur in great numbers in a virtually continuous series of black shales. Sheldon (1987) studied a sequence spanning some 3 Ma, in which there are eight common trilobite lineages.

In all of the eight genera, measured from 15 000 specimens, there was a net increase in the number of pygideal ribs, a character used in species diagnosis. It is a striking example of gradual evolution occurring in parallel in the various genera. Equally, Sheldon demonstrated that there are character reversals from time to time, such as temporary decrease in rib number. There is no reason why character reversals such as this should not take place, and here they are clearly demonstrated. This is one of the best examples of gradualistic genetic change known from the fossil record, though the selection pressures that caused it remain uncertain.

The original paper is P Sheldon: 'Parallel gradualistic evolution of Ordovician trilobites', Nature 330, 561-3, 1987.

Ed, please explain the sorting process during a flood that could produce such findings.

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