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Author Topic:   Embryonic fossils 500 MY old - a YEC explanation?
EZscience
Member (Idle past 5154 days)
Posts: 961
From: A wheatfield in Kansas
Joined: 04-14-2005


Message 1 of 15 (356675)
10-15-2006 12:09 PM


The really novel nature of this work is the visualization of intracellular structure of embryonic cells that are 550 MY old.
The discovery of such delicate microstructures in fossilized form is unprecedented to my knowledge.
They provide a unique opportunity to contrast the cellular development of very primitive extinct animals with that of extant organisms that are already well described. A number of important similarities and contrasts have already been noted. These comparisons will provide insights into how cellular development has evolved since the Cambrian explosion and evolutionary theory is certain to be used in interpreting their significance.
A focus of the discussion could be that the very primitive intracellular structure revealed is consistent with the evolutionary view that no complex life existed at that time and completely inconsistent with the Creo view that all life was created at once, and that what followed was a loss of diversity after 'The Fall'.
Regardless of any contention that dating techniques might be flawed, these geological strata, that were apparently formed in conditions remarkably conducive to fossilization, contain no complex higher organisms that should be there if the Creo view were to be supported.
Here is the Astract from the Science article.
quote:
Stereoblastic embryos from the Doushantuo Formation of China exhibit occasional asynchronous cell division, with diminishing blastomere volume as cleavage proceeded. Asynchronous cell division is common in modern embryos, implying that sophisticated mechanisms for differential cell division timing and embryonic cell lineage differentiation evolved before 551 million years ago. Subcellular structures akin to organelles, coated yolk granules, or lipid vesicles occur in these embryos. Paired reniform structures within embryo cells may represent fossil evidence of cells about to undergo division. Embryos exhibit no evidence of epithelial organization, even in embryos composed of 1000 cells. Many of these features are compatible with metazoans, but the absence of epithelialization is consistent only with a stem-metazoan affinity for Doushantuo embryos.
Released from Message 3 of thread Embryonic fossils 500 MY old - a YEC explanation? in the [forum=-25] forum. --Admin

Replies to this message:
 Message 2 by Coragyps, posted 10-15-2006 12:30 PM EZscience has not replied
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Coragyps
Member (Idle past 734 days)
Posts: 5553
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 2 of 15 (356679)
10-15-2006 12:30 PM
Reply to: Message 1 by EZscience
10-15-2006 12:09 PM


I can email pdf's of the paper and of non-free-access papers in Nature or Science that it references to any of you that are interested - just ask. Some of the pictures are pretty amazing.

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EZscience
Member (Idle past 5154 days)
Posts: 961
From: A wheatfield in Kansas
Joined: 04-14-2005


Message 3 of 15 (356715)
10-15-2006 3:52 PM


A more reader-friendly link...
can be found at the BBC site here A form of tomography, microCT, was used to visualize interior structures in the rock.
Using digital reconsruction, the organelles of specific embryonic cells could be visualized and conpared to those of modern embryonic eukariotes.
Quotes from one of the scientists:
S. Xiao writes:
It is amazing that such delicate biological structures can be preserved in such an ancient deposit. We digitally extracted each cell from the embryos and then looked inside the cells.
The consensus was that the embryos were those of very primitive sponge-like animals.
This apparently rich bed of fossil embryos dates to the pre-Cambrian (around the time of the Burgess shale) and the primitive intracelluar structure supports the view that multi-cellular life forms were not yet highly evolved before the 'Cambrian explosion'.
Edited by EZscience, : No reason given.

Replies to this message:
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Archer Opteryx
Member (Idle past 3598 days)
Posts: 1811
From: East Asia
Joined: 08-16-2006


Message 4 of 15 (356809)
10-16-2006 5:19 AM
Reply to: Message 1 by EZscience
10-15-2006 12:09 PM


Thanks for sharing this. I saw the BBC article. Very exciting find!
.

Archer
All species are transitional.

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 Message 1 by EZscience, posted 10-15-2006 12:09 PM EZscience has not replied

  
JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 5 of 15 (356826)
10-16-2006 8:42 AM


FWIW, there's a creationist al talk.origins arguing that it's contamination. News: Fossil embryos caught in the act of dividing (the sixth message in the tree).

  
Larni
Member (Idle past 164 days)
Posts: 4000
From: Liverpool
Joined: 09-16-2005


Message 6 of 15 (357671)
10-20-2006 9:09 AM
Reply to: Message 3 by EZscience
10-15-2006 3:52 PM


Re: A more reader-friendly link...
What a find, fascinating stuff thanks for the lnky.
Of course this will not wash with YECers. Nothing else seems to.

This message is a reply to:
 Message 3 by EZscience, posted 10-15-2006 3:52 PM EZscience has not replied

  
mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 7 of 15 (357682)
10-20-2006 9:36 AM
Reply to: Message 3 by EZscience
10-15-2006 3:52 PM


Re: A more reader-friendly link...
EZ,
This apparently rich bed of fossil embryos dates to the pre-Cambrian (around the time of the Burgess shale) and the primitive intracelluar structure supports the view that multi-cellular life forms were not yet highly evolved before the 'Cambrian explosion'.
Pedantic point of order; the Burgess Shale was Cambrian, the "embryo beds" predate this by quite a margin in the Precambrian. But interesting stuff, thanks for the heads-up.
Mark

There are 10 kinds of people in this world; those that understand binary, & those that don't

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EZscience
Member (Idle past 5154 days)
Posts: 961
From: A wheatfield in Kansas
Joined: 04-14-2005


Message 8 of 15 (357689)
10-20-2006 10:04 AM
Reply to: Message 7 by mark24
10-20-2006 9:36 AM


Re: A more reader-friendly link...
Yes, quite correct. Earlier than the Burgess Shale, but still consistent with a lack of multicellular diversity in the Pre-Cambrian.

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Replies to this message:
 Message 9 by jar, posted 10-20-2006 11:39 AM EZscience has replied

  
jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 9 of 15 (357710)
10-20-2006 11:39 AM
Reply to: Message 8 by EZscience
10-20-2006 10:04 AM


Re: A more reader-friendly link...
Yes, quite correct. Earlier than the Burgess Shale, but still consistent with a lack of multicellular diversity in the Pre-Cambrian.
Uhmmmmm, not quite.
There seems to be lots of newer evidence being found that shows more than even simple multicelular critters and even bilateral critters existing in the pre-cambrian. In particular the recent work of Chen etal describing findings from China point to a substancial body of diversity during the late precambrian period.
Shelly microfossils
Pre-Cambrian Animal Life

Aslan is not a Tame Lion

This message is a reply to:
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Replies to this message:
 Message 10 by EZscience, posted 10-20-2006 12:00 PM jar has replied

  
EZscience
Member (Idle past 5154 days)
Posts: 961
From: A wheatfield in Kansas
Joined: 04-14-2005


Message 10 of 15 (357716)
10-20-2006 12:00 PM
Reply to: Message 9 by jar
10-20-2006 11:39 AM


Cnidarians etc.
Yes, there was obviously Pre-Cambrian diversity in primitive groups like cnidarians etc. What the Cambrian explosion really represented was the appearance of multiple new and more complex body plans with both bilateral and radial symmetry, many of which gave rise to the extant lineages of higher organisms we see today, and many strange 'experiments' that left no descendents at all, but would be considered to represent novel phyla if they were alive today. Although there wasn't a lack of diversity prior to the Cambrian boundary it was limited, and diversity of higher life forms began an exponential increase at that point.

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 Message 9 by jar, posted 10-20-2006 11:39 AM jar has replied

Replies to this message:
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jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 11 of 15 (357724)
10-20-2006 12:12 PM
Reply to: Message 10 by EZscience
10-20-2006 12:00 PM


Re: Cnidarians etc.
What the Cambrian explosion really represented was the appearance of multiple new and more complex body plans with both bilateral and radial symmetry, many of which gave rise to the extant lineages of higher organisms we see today, and many strange 'experiments' that left no descendents at all, but would be considered to represent novel phyla if they were alive today.
But I was under the impression that we were now finding examples of both bilateral and radial symmetry 40-50 million years before the cambrian.
As one such example

Aslan is not a Tame Lion

This message is a reply to:
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Replies to this message:
 Message 12 by EZscience, posted 10-20-2006 12:21 PM jar has replied

  
EZscience
Member (Idle past 5154 days)
Posts: 961
From: A wheatfield in Kansas
Joined: 04-14-2005


Message 12 of 15 (357729)
10-20-2006 12:21 PM
Reply to: Message 11 by jar
10-20-2006 12:12 PM


Re: Cnidarians etc.
Definitely, yes. But bilateral symmetry does not imply much complexity - it only sets the stage for a polarized body plan with a head end and a tail end. These were very primitive microscopic organisms.

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 Message 11 by jar, posted 10-20-2006 12:12 PM jar has replied

Replies to this message:
 Message 13 by jar, posted 10-20-2006 12:28 PM EZscience has replied

  
jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 13 of 15 (357731)
10-20-2006 12:28 PM
Reply to: Message 12 by EZscience
10-20-2006 12:21 PM


Re: Cnidarians etc.
But bilateral symmetry does not imply much complexity - it only sets the stage for a polarized body plan with a head end and a tail end. These were very primitive microscopic organisms.
Certainly.
However what it does show is that the basics for life as we see it today go back at least to the precambrian, and that the precambrian is NOT some sudden appears of forms never before seen, but rather the basics for the lifeforms found in the cambrian explosion can be seen more than 40 million years earlier.
Neither of these facts seem to provide much of a YEC explanation though and so far I have noticed that as usual, the YEC model to explan what is seen has been noticably missing from this thread.
Why is it that so far NO YEC has ever been able to present a model that adequately explains anything seen?

Aslan is not a Tame Lion

This message is a reply to:
 Message 12 by EZscience, posted 10-20-2006 12:21 PM EZscience has replied

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EZscience
Member (Idle past 5154 days)
Posts: 961
From: A wheatfield in Kansas
Joined: 04-14-2005


Message 14 of 15 (357745)
10-20-2006 1:00 PM
Reply to: Message 13 by jar
10-20-2006 12:28 PM


Re: Cnidarians etc.
jar writes:
Why is it that so far NO YEC has ever been able to present a model that adequately explains anything seen?
Apart from the fact they are working from a flawed premise?
I think that models derived from biblical accounts of nature are constructed with the objective of engineeering a consistency with pre-existing assumptions, rather than trying to achieve any paradigm shift in understanding.
They are not designed to explain, only to confirm what is already assumed. Nor can their fundamental assumptions or premises be questioned or subject to modification. Thus we should not expect evolving, functional explanations to be generated by religiously-derived models of nature.
In a sense, most great scientific advances are iconoclastic in nature, and iconclasts are anathema within religious sects, most of which decry any intellectual doubt in hopes of perpetuating their own world view without change.

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Hongi
Inactive Member


Message 15 of 15 (363866)
11-15-2006 7:31 AM
Reply to: Message 2 by Coragyps
10-15-2006 12:30 PM


Could I have the PDF for the OP? Thank you.

This message is a reply to:
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