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Author Topic:   "transitional" turtle found
Taz
Member (Idle past 3292 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 1 of 20 (489521)
11-27-2008 11:27 PM


Been waiting for one of you guys to post this. News first came out yesterday. I can't believe you guys missed this. Anyway, I'd like to see what our fellow creo friends have to say about this turtle without the upper shell. This creature also had teeth.
China's ancestral turtle sheds light on evolution | Reuters
quote:
By Tan Ee Lyn
HONG KONG (Reuters) - Researchers in China have unearthed fossils of the most primitive turtle to date, a creature with teeth, a fully formed belly shell and a back shell that appeared to be just evolving.
In an article published in Nature, they said the Odontochelys lived about 220 million years ago and their discovery sheds light on one of the biggest mysteries in reptile evolution -- how the shell and body of the turtle developed.
Their discovery displaces the Proganochely, another class of turtle previously thought to be the oldest. With fully formed upper and lower shells, the Proganochely was found in Germany and was 10 million years younger than the Odontochely.
"What we found (Odontochely) is an intermediate missing link," lead researcher Li Chun at the Chinese Academy of Sciences said in a telephone interview from Beijing.
"The German turtle is already very similar to the turtles we know of today. But we had never known how the turtle shell evolved. It couldn't have just appeared suddenly."
From the three Odontochely fossils discovered in China, Li said it was clear the turtle first developed the plastron, or the lower shell that encases the belly, before getting its upper shell, or the carapace.
"The plastron developed first and after it was fully formed, then the carapace developed," he said.
The fossils were uncovered in marine deposits in the Nanpanjiang Trough Basin in China's southern Guizhou province. Two of the fossils were complete.
Li said the three fossils, two between 20 and 30 cm and the third about 40 cm showed early evolvement of the carapace.
"They had neural plates, which is the part that develops first on the back shell," he said.
Li said the creatures were meat eaters.
"They were aquatic animals but we cannot be certain if they were freshwater or saltwater."

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RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 2 of 20 (489582)
11-28-2008 10:58 AM
Reply to: Message 1 by Taz
11-27-2008 11:27 PM


turtle on the half-shell, with pictures
We're Sorry - Scientific American
Pictures of one of the fossils and an artist rendition, plus:
quote:
Researchers report in Nature today that the fossil indicates shells evolved as an extension of turtles' backbones and ribs.
They conclude that the bones belonged to a Triassic turtle ancestor, which they named Odontochelys semitestacea, meaning "toothed turtle with a half shell."
The newly discovered species sported a shelled belly and a little extra bone on its spine, supporting the theory that turtles' shells formed over eons as their backbones and ribs grew.
Once again, adaptation of existing hardware
Enjoy.

we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


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Cluim
Junior Member (Idle past 5592 days)
Posts: 7
Joined: 12-02-2008


Message 3 of 20 (490138)
12-02-2008 4:22 PM


quote:
I'd like to see what our fellow creo friends have to say about this turtle without the upper shell.
I'm not exactly sure what you mean by wondering what creationists have to think about this... sounds like you're implying this would disprove it, or creationists would be put off by this?
I don't think any reasonable creationist is arguing against microevolution. It exists. Period. There's tangible and undeniable proof, and it in no way contradicts creationism. We just don't believe monkeys became men, and other macroevelutional appeals that indeed have evidence, but don't have proof.

Replies to this message:
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subbie
Member (Idle past 1255 days)
Posts: 3509
Joined: 02-26-2006


Message 4 of 20 (490140)
12-02-2008 4:43 PM
Reply to: Message 3 by Cluim
12-02-2008 4:22 PM


Cluim, welcome to E v C!
quote:
We just don't believe monkeys became men, and other macroevelutional appeals that indeed have evidence, but don't have proof.
What kind of evidence would you need to see to accept "macroevolution?"
(BTW, avoid the use of the word "proof" when discussing matters of science. Science never considers anything proven. Instead, it's a matter of the supporting evidence. All scientific conclusions are subject to revision if new evidence is discovered.)

Those who would sacrifice an essential liberty for a temporary security will lose both, and deserve neither. -- Benjamin Franklin
We see monsters where science shows us windmills. -- Phat

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CosmicChimp
Member
Posts: 311
From: Muenchen Bayern Deutschland
Joined: 06-15-2007


Message 5 of 20 (490141)
12-02-2008 5:03 PM
Reply to: Message 3 by Cluim
12-02-2008 4:22 PM


I don't think any reasonable creationist is arguing against microevolution. It exists. Period. There's tangible and undeniable proof, and it in no way contradicts creationism.
How would you define microevolution and macroevolution? Where do you draw the line on the continuum, so to speak?

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bluescat48
Member (Idle past 4190 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 6 of 20 (490142)
12-02-2008 5:14 PM
Reply to: Message 3 by Cluim
12-02-2008 4:22 PM


I don't think any reasonable creationist is arguing against microevolution.
You call a transitional between unshelled, toothed & shelled, untoothed microevolution?
The term turtle applies to a whole order, Chelonia. That would mean that the difference between the Ape species, including humans, is microevolution.

There is no better love between 2 people than mutual respect for each other WT Young, 2002
Who gave anyone the authority to call me an authority on anything. WT Young, 1969

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Cluim
Junior Member (Idle past 5592 days)
Posts: 7
Joined: 12-02-2008


Message 7 of 20 (490154)
12-02-2008 7:24 PM


quote:
How would you define microevolution and macroevolution? Where do you draw the line on the continuum, so to speak?
I'd draw the same line in correlation to how I'm learning about it in my college Biology class; microevolution referring to small changes over a long time, and macroevolution referring to large changes. Example, for micro, specifically species adapting to a change in the environment for example, by maybe growing more fur or something to that nature. For macro, I'd use the same example I said before, but not limited to, some sort of primate becoming a human. Small change with strong evidence, as opposed to large change that has just as much evidence as the Bible does---just enough to where you need to put faith in to believe in it.
quote:
What kind of evidence would you need to see to accept "macroevolution?"
(BTW, avoid the use of the word "proof" when discussing matters of science. Science never considers anything proven. Instead, it's a matter of the supporting evidence. All scientific conclusions are subject to revision if new evidence is discovered.)
I apologize, and will refrain from specifically referring to a word as defining as "proof" in what I say in regards to that. Evidence to accept what I defined as macroevolution would be plausible enough evidence that is there to define microevolution. We have findings of of species and such within short periods of time (i.e. just decades to maybe so many hundreds of thousands years at tops) that we can say are the same and pinpoint small changes in them gradually over millions of years, but when something like trying to say the skulls of apes gradually turn into man? Most the skulls trying to say this are carbon dated and separated by MILLIONS of years apart! What about within these MILLIONS of years? They are TOO far apart to connect. Who is to say they weren't just a new and died out species?
That's just an example, there is more to subject than that obviously, and it's not just limited to such, but I'm just laying down the concept of how I see it.
quote:
You call a transitional between unshelled, toothed & shelled, untoothed microevolution?
The term turtle applies to a whole order, Chelonia. That would mean that the difference between the Ape species, including humans, is microevolution.
This was apparently dated 220 millions of years ago.. is that too short for a change to be defined as microevolution? I apologize for not being familiar with dates and times, and will take back what I said if in major conflict with such. But also being 220 millions of years ago, who is to say this itself wasn't just a random different species, and simply died out? Rather than the entire order of Chelonia coming from that to what they have today?
~~~I apologize if anything I say here is being irrational, I'm new to getting into this stuff because I've only recently taken an interest in such. I'm taking good note to what is being replied to me, and would appreciate any further revisions and corrections on what I say if necessary.

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RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 8 of 20 (490157)
12-02-2008 7:52 PM
Reply to: Message 3 by Cluim
12-02-2008 4:22 PM


partially formed features and creationist "transitional" fossils
Welcome to the fray, Cluim,
I'm not exactly sure what you mean by wondering what creationists have to think about this... sounds like you're implying this would disprove it, or creationists would be put off by this?
Probably because creationists have asked for years for fossils of organisms with partially formed features, thinking that this is a necessary element of transitional development of what they conceive to be macroevolution.
This is an organism with a partially formed feature - it only has the bottom shell and the center of the top shell.
This not only fills the bill for a fossil with a partially formed feature, it actually demonstrates that evolution works by incremental steps with fully functional living organisms at every stage, and it shows that "macroevolution" is nothing more than "microrevolution" carried out over many generations.
I don't think any reasonable creationist is arguing against microevolution. It exists. Period. There's tangible and undeniable proof, and it in no way contradicts creationism.
There is also no different mechanism, no different process, for "macroevolution" than we see, observe, document and agree about being involved in "microevolution" -- it is just the same evolution carried out over generations.
The only reason you have different organisms, rather than all one kind of organism, is because of speciation -- where isolated populations evolve on different lines due to (a) different mutations within their subpopulations (b) no mechanism to share new mutations with the other population (c) different environment for each population means different selection operating on mutations -- until a point is reached where they do not see the other population as potential mates. Note that:
  1. the evolution involved in each subpopulation is still "microevolution" and
  2. once they have diverged into reproductively isolated subpopulations there is no mechanism to keep them from diverging further by additional variation and selection as they adapt to new and constantly changing environments, and finally,
  3. by this process, repeated in every population of organisms as one generation follows the previous, every population of living organisms undergoes evolution ...
It is an ongoing process, and because variation is inevitable (mutations constantly occur), because isolation of subpopulations is inevitable (no species can cover the earth and still interbreed), and because environmental change is inevitable (long term climate changes), and because selection is inevitable (more young are produced every year than are needed to replace the parent population) ... evolution - the change in hereditary traits in populations from generation to generation - and speciation - the increased diversity of non-interbreeding populations - are inevitable.
We just don't believe monkeys became men, and other macroevelutional appeals that indeed have evidence, but don't have proof.
Unfortunately for you, nature is completely unimpressed with your opinion, nor is it restricted in any way from continuing to behave according to the natural laws of life, regardless of what you - or anyone - believe to occur or have occurred.
Enjoy.

we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


• • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

This message is a reply to:
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anglagard
Member (Idle past 837 days)
Posts: 2339
From: Socorro, New Mexico USA
Joined: 03-18-2006


Message 9 of 20 (490158)
12-02-2008 8:00 PM
Reply to: Message 7 by Cluim
12-02-2008 7:24 PM


A Few Misconceptions
Welcome to EvC Cluim!
Most the skulls trying to say this are carbon dated and separated by MILLIONS of years apart!
The fossils are not carbon dated because radiocarbon dating is not generally accurate beyond 50,000 years and not at all accurate beyond 100,000 years due to having so few atoms of leftover C14. Generally, such fossils are dated by their placement in the geologic record which is dated using various argon isotopes and paleomagnetism in associated volcanic deposits that must have occurred at roughly the same time according to basic geologic principles such as superposition.
What about within these MILLIONS of years? They are TOO far apart to connect. Who is to say they weren't just a new and died out species?
The various fossils associated with the human lineage over the last 5 million years are not themselves separated by millions of years but rather orders of tens to hundreds of thousands. In fact in several instances different species actually overlap in time as shown here.
This particular thread is not the place to discuss human evolution so further exploration of the topic may either be in other preexisting threads or perhaps one of your own invention. I would direct you to the proper area myself but have not kept up with every post here recently. Perhaps others could help in this matter.

Read not to contradict and confute, not to believe and take for granted, not to find talk and discourse, but to weigh and consider - Francis Bacon
The more we understand particular things, the more we understand God - Spinoza

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CosmicChimp
Member
Posts: 311
From: Muenchen Bayern Deutschland
Joined: 06-15-2007


Message 10 of 20 (490160)
12-02-2008 8:03 PM
Reply to: Message 7 by Cluim
12-02-2008 7:24 PM


I'd draw the same line in correlation to how I'm learning about it in my college Biology class; microevolution referring to small changes over a long time, and macroevolution referring to large changes. Example, for micro, specifically species adapting to a change in the environment for example, by maybe growing more fur or something to that nature. For macro, I'd use the same example I said before, but not limited to, some sort of primate becoming a human. Small change with strong evidence, as opposed to large change that has just as much evidence as the Bible does---just enough to where you need to put faith in to believe in it.
Small changes (micro-) can accumulate. The sum total of that type of accumulation can and often times does add up to a large scale change (macro-). You can see that as true right?

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RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 11 of 20 (490165)
12-02-2008 8:25 PM
Reply to: Message 7 by Cluim
12-02-2008 7:24 PM


Hello again Cluim,
I'd draw the same line in correlation to how I'm learning about it in my college Biology class; ...
Excellent start.
... microevolution referring to small changes over a long time, and macroevolution referring to large changes ...
For macro, I'd use the same example I said before,...
Evidence to accept what I defined as macroevolution would be plausible enough evidence that is there to define microevolution.
Pardon me if I quibble, but I don't see what your definition of "macroevolution" involves. What is "large" change compared to "small" change? Does it occur in one generation or over many?
As a guide I would point to university definitions, such as this one from Berkeley University:
quote:
The Definition:
Biological evolution, simply put, is descent with modification. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations). Evolution helps us to understand the history of life.
The Explanation:
The central idea of biological evolution is that all life on Earth shares a common ancestor, just as you and your cousins share a common grandmother.
Note that they divide small scale change as being within a breeding population, and that "large-scale evolution" occurs via speciation where subpopulations diversify from a parent "common ancestor" population.
and this one from the University of Michigan:
quote:
Definitions of Biological Evolution
We begin with two working definitions of biological evolution, which capture these two facets of genetics and differences among life forms. Then we will ask what is a species, and how does a species arise?
  • Definition 1: Changes in the genetic composition of a population with the passage of each generation
  • Definition 2: The gradual change of living things from one form into another over the course of time, the origin of species and lineages by descent of living forms from ancestral forms, and the generation of diversity
    Note that the first definition emphasizes genetic change. It commonly is referred to as microevolution. The second definition emphasizes the appearance of new, physically distinct life forms that can be grouped with similar appearing life forms in a taxonomic hierarchy. It commonly is referred to as macroevolution.
  • So what we see is that "large scale change" occurs by "small scale change" within populations as they diverge from other populations.
    Evidence to accept what I defined as macroevolution would be plausible enough evidence that is there to define microevolution. We have findings of of species and such within short periods of time (i.e. just decades to maybe so many hundreds of thousands years at tops) that we can say are the same and pinpoint small changes in them gradually over millions of years, but when something like trying to say the skulls of apes gradually turn into man? Most the skulls trying to say this are carbon dated and separated by MILLIONS of years apart! What about within these MILLIONS of years? They are TOO far apart to connect. Who is to say they weren't just a new and died out species?
    Within those millions of years you have genetic changes that are not as distinct. Often the early fossils of one "species" are not that different from the later fossils of a previous "species" - it is just that humans have drawn an arbitrary line to divide the fossils for ease of reference. In addition, evolution is not a steady state process, but occurs in fits and spurts, especially in response to environmental changes.
    Thus we see a fossil of an organism that is intermediate in form from a non shelled toothed creature to a shelled and toothless early turtle, an organism that demonstrates the accumulation of hereditary changes over time, or what evolutionary biologists define as macroevolution.
    Enjoy.
    Edited by RAZD, : hide off topic portion on human evolution
    Edited by RAZD, : space

    we are limited in our ability to understand
    by our ability to understand
    Rebel American Zen Deist
    ... to learn ... to think ... to live ... to laugh ...
    to share.


    • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

    This message is a reply to:
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    Cluim
    Junior Member (Idle past 5592 days)
    Posts: 7
    Joined: 12-02-2008


    Message 12 of 20 (490169)
    12-02-2008 8:59 PM


    Thanks for the welcomes.
    Anglagard--
    quote:
    The fossils are not carbon dated because radiocarbon dating is not generally accurate beyond 50,000 years and not at all accurate beyond 100,000 years due to having so few atoms of leftover C14. Generally, such fossils are dated by their placement in the geologic record which is dated using various argon isotopes and paleomagnetism in associated volcanic deposits that must have occurred at roughly the same time according to basic geologic principles such as superposition.
    I was aware of the inaccuracy of carbon dating after so many years, as you've said, and, silly of me enough, I learned just yesterday that that's how such fossils as those are generally dated, yet was still stuck on carbon. I digress.
    quote:
    The various fossils associated with the human lineage over the last 5 million years are not themselves separated by millions of years but rather orders of tens to hundreds of thousands. In fact in several instances different species actually overlap in time as shown here.
    I guess I was speaking of the earliest stages of humans, which after consulting my biology book, the earliest was 6-7 millions of years ago, and various gradual changing ones with every million years or so. Maybe not MILLIONS of years apart, but still some pretty daring gaps for the best clarity? I guess that's just an open opinion though, like I said, I'm still trying to get into this stuff, so, shows how much I know anyway, lol.
    CosmicChimp--
    quote:
    Small changes (micro-) can accumulate. The sum total of that type of accumulation can and often times does add up to a large scale change (macro-). You can see that as true right?
    Surely. Maybe I differentiated between the two on a scale larger than it actually was. Makes sense.
    And, RAZD... very well-put collection of the concept at hand. But for me, I'm going by more than just belief. But that's just experience that I can't put on anyone else, however explains my aspiration for this subject. I'll by no means be close-minded to evidence, yet to a degree, I guess I am ultimately close-minded at the end. I look forward to further future discussion--probably still in this board, but as Anglagard said, not straying as far from the OP as we may already have.
    Need to read me some books and good websites after finals... maybe even that long Wikipedia article, lol.

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    Cluim
    Junior Member (Idle past 5592 days)
    Posts: 7
    Joined: 12-02-2008


    Message 13 of 20 (490172)
    12-02-2008 9:10 PM


    Looks like you slipped in another reply before my last post, RAZD! I'll def check it out and read it over a little more carefully later though, as, like I said, finals are dawning over me quicker than I'd like, so I'm gonna have to scoot. Look forward to getting back into this though soon.

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    RAZD
    Member (Idle past 1405 days)
    Posts: 20714
    From: the other end of the sidewalk
    Joined: 03-14-2004


    Message 14 of 20 (490173)
    12-02-2008 9:14 PM
    Reply to: Message 12 by Cluim
    12-02-2008 8:59 PM


    Good stuff Cluim,
    I'll by no means be close-minded to evidence, yet to a degree, I guess I am ultimately close-minded at the end.
    Consider that an open-minded skeptic does not accept any position without reason, and is willing to discard any concept that is contradicted by evidence.
    I look forward to further future discussion--probably still in this board, but as Anglagard said, not straying as far from the OP as we may already have.
    We can always start a new topic on whatever interests you. If you want to discuss the issue of how much change is "large" change for instance, we could go through a review of the Dogs will be Dogs will be ??? thread.
    Enjoy.

    we are limited in our ability to understand
    by our ability to understand
    Rebel American Zen Deist
    ... to learn ... to think ... to live ... to laugh ...
    to share.


    • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

    This message is a reply to:
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    RAZD
    Member (Idle past 1405 days)
    Posts: 20714
    From: the other end of the sidewalk
    Joined: 03-14-2004


    Message 15 of 20 (490175)
    12-02-2008 9:22 PM
    Reply to: Message 13 by Cluim
    12-02-2008 9:10 PM


    No problem Cluim, looks like we are crossing posts.
    I'll def check it out and read it over a little more carefully later though, ...
    Just remember that the way evolutionary biologists study evolutionary biology is with the terms defined within the field of evolutionary biology. If anyone tries to use a different definition for a term, then they are really talking about a different concept, and this leads to confusion. Using a wrong definition, then can lead to logically invalid conclusions, when mixed into a discussion.
    Enjoy.

    we are limited in our ability to understand
    by our ability to understand
    Rebel American Zen Deist
    ... to learn ... to think ... to live ... to laugh ...
    to share.


    • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •

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