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Author
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Topic: nested heirarchies as evidence against darwinian evolution
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skepticfaith
Member (Idle past 5752 days) Posts: 71 From: NY, USA Joined: 08-29-2006
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Message 121 of 248 (452096)
01-29-2008 2:01 PM
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Reply to: Message 110 by Modulous
01-29-2008 12:54 PM
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quote:
What happened was that A branched into B and C. A ceased to exist. Thus A will never diverge again, since extinct populations don't reproduce by definition.
NO! Group A continued to reproduce and remained essentially the SAME until present time. Some species did go extinct but the ones that remained other than a few superficial changes remain the same. I find it strange that such well observed fact is being disputed. Take invertebrates for instance, how much 'evolutionary change' has occurred in each species - they have remained essentially the same for eons. Many species have gone extinct but the remaining haven't changed much.
| This message is a reply to: | | | Message 110 by Modulous, posted 01-29-2008 12:54 PM | | Modulous has replied |
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Tanypteryx
Member Posts: 4451 From: Oregon, USA Joined: 08-27-2006 Member Rating: 5.5
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skepticfaith writes: Take invertebrates for instance Which invertebrates are you talking about? All the animals that are not in Phylum Chordata are invertebrates.
how much 'evolutionary change' has occurred in each species - they have remained essentially the same for eons. Many species have gone extinct but the remaining haven't changed much. I do not understand what you mean. The remaining invertebrate species (comprising the other 32 phyla) have radiated into millions of species alive today. Very few, if any, resembling the original founding species of the various phyla.
What if Eleanor Roosevelt had wings? -- Monty Python You can't build a Time Machine without Weird Optics -- S. Valley
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mark24
Member (Idle past 5226 days) Posts: 3857 From: UK Joined: 12-01-2001
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Message 123 of 248 (452169)
01-29-2008 4:23 PM
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Reply to: Message 113 by randman
01-29-2008 1:05 PM
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Re: convergent evolution
randman,
Your post does not address my point. We are not discussing the posited evolutionary lines, per se...at least on this point, that theorically occured from the phyla that appeared in the Cambrian explosion or existed then, but why the same process that produced those phyla did not continue to do so for the next 500 million years. My post exactly addressed your point, & I have been saying the same thing since my first post. I repeat, from my last post:
quote:
But an organism belonging to a phylum will always belong to that phylum, all its descendents will always belong to that phylum. They cannot begat another phylum as the rules of classification do not allow it. In other words, no-new-phyla is an artifact of our classification system, evolution continues unabated, however.
—mark
Way back in post 41 I said pretty much the same thing:
quote:
Whatever evolves from chordate stock remains in the monophyletic group chordata. It matters not one iota whether it can fly, breathe underwater or just sits plant-like on a rock filter feeding. If its ancestors were chordates, it is a chordate. It cannot be in two phyla at once. If something within phylum chordata without a vertebral column evolves a vertebral column, it may warrant a new taxon all of its own, but that taxon will be within phylum chordata, not outside of it. No new phylum.
—mark
Waaaaaaaay back in post 8:
quote:
Cladistically speaking it couldn't really happen, anyway. Any radical new bauplan would still belong to an extant phyla because it would be ancestral to it.
—mark
That's no less than three times that I alone have explained why there have been no new animal phyla since the Cambrian. So, just for kicks I'll explain it a fourth time; An organism belonging to a phylum exists within a monophyletic clade. All of it's descendents must therefore belong to that phylum & that phylum alone. It is an artifact of the classification system not the mode & tempo of evolution that limits new clades of high taxonomic rank. Mark
There are 10 kinds of people in this world; those that understand binary, & those that don't
| This message is a reply to: | | | Message 113 by randman, posted 01-29-2008 1:05 PM | | randman has not replied |
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Modulous
Member Posts: 7801 From: Manchester, UK Joined: 05-01-2005
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NO! Group A continued to reproduce and remained essentially the SAME until present time. Show me this ancestral population of animals then. Show me this unevolved population that is the same species of beings as the proposed common ancestor of all living animals. When we find that mythical being reproducing today we can advance the discussion. If you really want to advance, we have to understand what evolutionary science actually says. Evolutionary science actually says that Group A is for all intents and purposes extinct. That is why evolutionary science does not predict that the descendant life forms will follow the same paths trodden by their ancestors. This is what we observe. Randman thinks that there is some discrepancy here, I am showing that no such discrepancy exists. Evolutionary biology says that A is extinct. The evidence suggests that A is not producing new phyla. The evidence is consistent with evolutionary biology.
Some species did go extinct but the ones that remained other than a few superficial changes remain the same. They might look similar to you but they are not the ancestral population. They have evolved considerably since then.
Take invertebrates for instance, how much 'evolutionary change' has occurred in each species - they have remained essentially the same for eons. Not the case at all. They have significantly evolved since then. They are different species, with different genomes. The ancestral population they descended from is long gone. New genes have come. Old genes have gone. Some genes are doing different things, some things are doing the same things. From this point, we would not expect this population to have similar descendants to those of their ancestral populations. They are starting from different places. Further: the selection pressures that exist are also different during the period of the ancestral life forms. If we were to go back in time, get a population of ancestors and put them in the modern world they would almost certainly evolve in a different way and produce a completely new collection of phyla, some of which maybe similar to existing phyla, some which will be quite different. Since life forms don't travel in time, we won't expect new phyla to appear.
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mark24
Member (Idle past 5226 days) Posts: 3857 From: UK Joined: 12-01-2001
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skepticfaith,
Take invertebrates for instance, how much 'evolutionary change' has occurred in each species - they have remained essentially the same for eons. Many species have gone extinct but the remaining haven't changed much. Chordates that were represented in the Cambrian by tunicates & seasquirty soft bodied organisms, that in the modern day now include, elephants, humans, eels & sharks. Please explain to those silly muddle headed biologists how this represents them not having changed much? For the record, seasquirts are members of phylum chordata that includes the vertebrates, but are invertebrates themselves. In other words, vertebrates evolved from invertebrates within the same phylum. This was illustrated with pretty pictures in message 75. Mark Edited by mark24, : No reason given. Edited by mark24, : No reason given.
There are 10 kinds of people in this world; those that understand binary, & those that don't
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skepticfaith
Member (Idle past 5752 days) Posts: 71 From: NY, USA Joined: 08-29-2006
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Message 126 of 248 (452189)
01-29-2008 5:11 PM
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Reply to: Message 124 by Modulous
01-29-2008 4:35 PM
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quote:
Show me this ancestral population of animals then. Show me this unevolved population that is the same species of beings as the proposed common ancestor of all living animals.
Actually you should show me ..) But just to clarify - What I meant by group A consists of thousands maybe millions of different species. One population of species X supposedly diverged evolved eventually forming species y,z etc and diverging out of this group. Now all we see are the results: this group B consisting of many different species whose common ancestor is species X from group A. I agree species X no longer exists. However group A still exists virtually unchanged = this is my point.
quote:
They might look similar to you but they are not the ancestral population. They have evolved considerably since then.
Sure, they reproduced many times but 'evolved' ? - No. Here is one species virtually unchanged. http://www.wildcalifornia.org/pressreleases/number-28 And to counter your point all the species that you claim to have evolved from ancient populations have appeared suddenly in the fossil record. The rest either are extinct or are UNCHANGED. Actually I don't mind if you show me a two or 3 species that HAVE changed over time in a major way. (macro evolution) I cannot name all the different species on this planet but just for starters - how about the Crocodile virtually unchanged before it suddenly appeared. The only changes that have been observed are variations in color size etc What bothers me about evolution is that the species that have supposedly changed seem to have appeared in a very short time. At the very least, the rate of evolution varies from very fast to very slow.
| This message is a reply to: | | | Message 124 by Modulous, posted 01-29-2008 4:35 PM | | Modulous has replied |
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skepticfaith
Member (Idle past 5752 days) Posts: 71 From: NY, USA Joined: 08-29-2006
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Message 127 of 248 (452192)
01-29-2008 5:13 PM
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Reply to: Message 125 by mark24
01-29-2008 4:36 PM
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quote:
Chordates that were represented in the Cambrian by tunicates & seasquirty soft bodied organisms, that in the modern day now include, elephants, humans, eels & sharks. Please explain to those silly muddle headed biologists how this represents them not having changed much?
They suddenly appeared in the fossil record. You assume they have evolved but I would like to see some evidence of this proposed evolution.
| This message is a reply to: | | | Message 125 by mark24, posted 01-29-2008 4:36 PM | | mark24 has replied |
| Replies to this message: | | | Message 130 by mark24, posted 01-29-2008 6:36 PM | | skepticfaith has not replied |
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Modulous
Member Posts: 7801 From: Manchester, UK Joined: 05-01-2005
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Actually you should show me ..) Nah - you are the one that claimed Group A is still reproducing. I don't think they exist. How can I show you something I don't think exists?
But just to clarify - What I meant by group A consists of thousands maybe millions of different species. One population of species X supposedly diverged evolved eventually forming species y,z etc and diverging out of this group. Now all we see are the results: this group B consisting of many different species whose common ancestor is species X from group A. I agree species X no longer exists. However group A still exists virtually unchanged = this is my point. What we are talking about is that Group A diverged into about 30 lineages. That is a few dozen species of the ancestral Group A evolved in separate directions and became the animal phyla. That is what the science tells us. Group A diversifies - it does not remain the same at all. There is photographic evidence of this diversification in this very thread.
Sure, they reproduced many times but 'evolved' ? - No. So are you suggesting that in 500 million years they have the retained the exact same genetic makeup, in spite of our knowledge that gene frequencies can change from one generation to the next? That is your opinion, but it is not the opinion of evolutionary biology. Since it is the opinions of evolutionary biology and the consequences of them that is under discussion, we should discuss them. Not your own ideas on natural history.
We are talking about the ancestor of all animals some 500 million years ago.
Actually I don't mind if you show me a two or 3 species that HAVE changed over time in a major way. See Message 75. According to natural history as per evolution, all of these share a common ancestor 500 million years ago or so. Since they are all so very different from one another, and yet their ancestral population were fairly similar - there must be more than 3 species shown in that post that have changed in a major way.
I cannot name all the different species on this planet but just for starters - how about the Crocodile virtually unchanged before it suddenly appeared. The only changes that have been observed are variations in color size etc Yes, and not much has descended from them has there? Again we are talking about a period much earlier than this, here is a possible common ancestor of humans and crocodiles (it isn't the most recent of course...). This little critter is extinct now, and won't be reproducing any more. And this is just for the chordates, which is once again later than the time we are discussing. Much change has happened since those times. It would be a more primitive ancestor than this that produced the phyla.
At the very least, the rate of evolution varies from very fast to very slow. Yes it does. And there is ample reason to suggest that this is perfectly normal. Even Darwin had worked out that there would be periods of stasis that are long compared with the periods of change.
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bluegenes
Member (Idle past 2508 days) Posts: 3119 From: U.K. Joined: 01-24-2007
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Your article uses the word species losely, for what is probably an ancient genus or family which has contained many species.
quote:
The organizations initially filed a scientific petition to list the green sturgeon in June 2001, documenting precipitous declines in this fish species that has survived more than 200 million years.
There, it should be genus or family.
quote:
Only three river systems are known to support green sturgeon today, in the Klamath-Trinity, Sacramento, and Rogue Rivers, with the species divided into at least two distinct populations that apparently do not interbreed.
Means there are two species of green sturgeon in those three rivers, apparently.
quote:
In North America only seven sturgeon species may now remain. Until recently, eight species of sturgeon occurred in North America--four of which (plus one population of the white sturgeon) are already listed as endangered or threatened; the Shortnose sturgeon, Gulf sturgeon, Pallid sturgeon, Alabama sturgeon, and the Kootenai River population of the white sturgeon
And the correct use of species there. These modern species are descendents of the 200 million year old species, and the same genus or family, but not the same species. They change over time, as all animals do, but just haven't changed much, meaning they obviously haven't needed to. They are certainly not the 500 million year "species A" that you're talking about. They are all in the same phylum and subphylum as us.
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mark24
Member (Idle past 5226 days) Posts: 3857 From: UK Joined: 12-01-2001
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skepticfaith,
They suddenly appeared in the fossil record. You assume they have evolved but I would like to see some evidence of this proposed evolution. So why ask how much evolutionary change has occurred? Clearly you thought the phyla appeared in the Cambrian & remained unchanged. This is false. Mark
There are 10 kinds of people in this world; those that understand binary, & those that don't
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molbiogirl
Member (Idle past 2672 days) Posts: 1909 From: MO Joined: 06-06-2007
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Message 131 of 248 (452251)
01-29-2008 9:03 PM
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Reply to: Message 93 by Percy
01-28-2008 8:45 PM
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Re: moving the topic forward
Well. I'm tired of waiting on Lith. Here's what I've found so far. A critical reappraisal of the fossil record of the bilaterian phyla Biological Reviews, Volume 75, Issue 2, Page 253-295, May 2003. From the abstract:
It has long been assumed that the extant bilaterian phyla generally have their origin in the Cambrian explosion, when they appear in an essentially modern form. Both these assumptions are questionable. A strict application of stem- and crown-group concepts to phyla shows that although the branching points of many clades may have occurred in the Early Cambrian or before, the appearance of the modern body plans was in most cases later: very few bilaterian phyla sensu stricto have demonstrable representatives in the earliest Cambrian. Given that the early branching points of major clades is an inevitable result of the geometry of clade diversification, the alleged phenomenon of phyla appearing early and remaining morphologically static is seen not to require particular explanation. Confusion in the definition of a phylum has thus led to attempts to explain (especially from a developmental perspective) a feature that is partly inevitable, partly illusory. We critically discuss models for Proterozoic diversification based on small body size, limited developmental capacity and poor preservation and cryptic habits, and show that the prospect of lineage diversification occurring early in the Proterozoic can be seen to be unlikely on grounds of both parsimony and functional morphology. Indeed, the combination of the body and trace fossil record demonstrates a progressive diversification through the end of the Proterozoic well into the Cambrian and beyond, a picture consistent with body plans being assembled during this time. Body-plan characters are likely to have been acquired monophyletically in the history of the bilaterians, and a model explaining the diversity in just one of them, the coelom, is presented. This analysis points to the requirement for a careful application of systematic methodology before explanations are sought for alleged patterns of constraint and flexibility. In other words, not all phyla were established during the Cambrian explosion. The author mentions the extensive fossil evidence of phyla established at "the end of the Proterozoic well into the Cambrian and beyond". The origins of many of the phyla has been pushed up into the succeeding Ordovician Period, or even later. In other words, the ~33 modern phyla developed over a period of 200+ million years. Which means, ~400 mya, the last phyla was established. Edited by molbiogirl, : No reason given.
| This message is a reply to: | | | Message 93 by Percy, posted 01-28-2008 8:45 PM | | Percy has not replied |
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randman 
Suspended Member (Idle past 4930 days) Posts: 6367 Joined: 05-26-2005
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Re: moving the topic forward
A critical reappraisal Pay attention to the word "reappraisal."
In other words, not all phyla were established during the Cambrian explosion. I hope we are not going to have play a game like definining what "is" means. Are you saying the phyla emerged after the Cambrian or simply that some emerged prior to the Cambrian. Note your comment below:
The author mentions the extensive fossil evidence of phyla established at "the end of the Proterozoic well into the Cambrian and beyond". Arguing that phyla appeared prior to the Cambrian explosion which the author admits is an attempted "reappraisal" of accepted opinion still does not help your case in the slightest.
The origins of many of the phyla has been pushed up into the succeeding Ordovician Period, or even later. Keep in mind this is someone trying to stretch the time of phyla evolving and introduce a reappraisal. Nor is it the latest research, but let's look at some factual mistakes on your part.
The Ordovician period is the second of the six (seven in North America) periods[1] of the Paleozoic era, and covers the time between 488.31.7 to 443.71.5 million years ago The Ordovician period ended 443 million years ago, not 400 million years. You also stated earlier:
The process did not end 500 million years ago. It has been mentioned, repeatedly, that only ~8 phyla were established in the Cambrian explosion. My argument was stating accepted fact, that all phyla existed in the Cambria era. You suggest that only 8 existed at that time. That is a serious factual error on your part. Even the revisionist guy you quote doesn't say that, but here is your chance. Please show where the other 25 animal phyla had not appeared by the time of the Cambria. If you cannot show this, then please retract your statement.
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Lithodid-Man
Member (Idle past 2961 days) Posts: 504 From: Juneau, Alaska, USA Joined: 03-22-2004
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Re: moving the topic forward
Molbiogirl writes: Well. I'm tired of waiting on Lith
Sorry I teach all day until 7 PM our time on Tuesdays (Phyla known through entire Phanerozoic, i.e. those Rand are calling most phyla are bolded) Acanthocephala No fossil record Acoelomorpha No fossil record Annelida Early Cambrian
Arthropoda Early Cambrian
Brachiopoda Early CambrianBryozoa Ordovician Chaetognatha Early CambrianChordata Middle Cambrian Cnidaria EdiacaranCtenophora Devonian Cycliophora No fossil record Echinodermata PrecambrianEchiura Upper Carboniferous Entoprocta No fossil record Gastrotricha No fossil record Gnathostomulida No fossil record Hemichordata Middle Cambrian Kinorhyncha No fossil record Loricifera No fossil record Mesozoa No fossil record Micrognathozoa No fossil record Mollusca Early CambrianMyxozoa No fossil record Nematoda Cretaceous Nematomorpha Middle Cambrian Nemertea Upper Carboniferous ('Tully monster', highly disputed as nemertean) Onychophora Middle Cambrian Orthonectida No fossil record Phoronida Devonian Placozoa No fossil record Platyhelmithes No fossil record Porifera Late PrecambrianPriapulida Middle Cambrian Rhombozoa No fossil record Rotifera Eocene Sipuncula No fossil record Tardigrada Middle Cambrian Xenoturbellida No fossil record Sorry rand, you were wrong. Out of the 38 extant currently accepted phyla only 8 are found from the lower Cambrian or before. A simple "okay, I was wrong" will suffice. I know of course that will not happen, and my work here will somehow prove you even more right. I have decided that I will refrain from posting for awhile, just going to enjoy the current chatter as it is. References: Boardman RS, Cheetham AH, and Rowell AJ (1987) Fossil Invertebrates. Blackwell Scientific Publications. Bostom MA. 713 pp. Brusca RC and Brusca GJ (2003) Invertebrates 2nd ed. Sinauer Associates Inc. Sunderland, MA. 936 pp. Valentine JW (2005) On the Origin of Phyla. University of Chicago Press. 608 pp.
Doctor Bashir: "Of all the stories you told me, which were true and which weren't?" Elim Garak: "My dear Doctor, they're all true" Doctor Bashir: "Even the lies?" Elim Garak: "Especially the lies"
| This message is a reply to: | | | Message 131 by molbiogirl, posted 01-29-2008 9:03 PM | | molbiogirl has not replied |
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randman
Suspended Member (Idle past 4930 days) Posts: 6367 Joined: 05-26-2005
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Message 134 of 248 (452311)
01-30-2008 1:20 AM
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Cambrian explosion
First, as the name implies, the fossils of the Cambrian explosion appear suddenly or abruptly within a very brief period of geologic time (see figures 1 and 2). As recently as 1992, paleontologists thought the Cambrian period began 570 million years ago and ended 510 million years ago, with the Cambrian explosion itself occurring within a 20-to-40-million-year window during the lower Cambrian period. In 1993, radiometric dating of zircon crystals from formations just above and just below Cambrian strata in
Siberia allowed for a precise recalibration of the age of Cambrian strata.
Radiometric analyses of these crystals fixed the start of the Cambrian period at 543 million years ago and the beginning of the Cambrian explosion
itself at 530 million years ago (see figure 2).4 These studies also
showed that the Cambrian explosion occurred within an exceedingly narrow
window of geologic time, lasting no more than 5 million years. Geologically
speaking, 5 million years represents a mere 0.11 percent of Earth’s
history. As Chinese paleontologist Jun-Yuan Chen has explained, “compared
with the 3-plus-billion-year history of life on earth, the period [of
the explosion] can be likened to one minute in 24 hours of one day.”5 Yet
most of the innovations in the basic architecture of animal forms occurred
abruptly within just such a small fraction of the earth’s history during the
Cambrian. Due to the suddenness of the appearance of animal life in the
Cambrian, the Cambrian explosion has now earned titles such as “The Big
Bang of Animal Evolution” (Scientific American), “Evolution’s Big Bang”
(Science), and the “Biological Big Bang” (Science News).6
To say that the fauna of the Cambrian period appeared in a geologically sudden manner also implies the absence of clear transitional intermediates connecting the complex Cambrian animals with those simpler living forms found in lower strata. Indeed, in almost all cases, the body plans and structures present in Cambrian period animals have no clear morphological antecedents in earlier strata. The Cambrian Explosion | Discovery Institute Btw, this is a published explicitly ID paper.
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molbiogirl
Member (Idle past 2672 days) Posts: 1909 From: MO Joined: 06-06-2007
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Message 135 of 248 (452315)
01-30-2008 1:52 AM
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Reply to: Message 132 by randman
01-30-2008 12:48 AM
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Re: moving the topic forward
Pay attention to the word "reappraisal." Yes. Just as relativity was a reappraisal of physics.
The Ordovician period ended 443 million years ago, not 400 million years. Conveniently chose to ignore "and beyond", did we?
If you cannot show this, then please retract your statement. Lith did the honors. Considering that several phyla are from Carboniferous, Devonian, Ordivician, etc., I need to push that 400 mya up to 300 mya.
| This message is a reply to: | | | Message 132 by randman, posted 01-30-2008 12:48 AM | | randman has replied |
| Replies to this message: | | | Message 140 by randman, posted 01-30-2008 2:27 AM | | molbiogirl has not replied |
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