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gezzam
SFN Regular
Australia
751 Posts |
Posted - 06/23/2002 : 06:51:16
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Have just bought a series of documentaries on DVD called “The Blue Planet” bought out by the BBC.
The narrator, David Attenborough, stated in one of the episodes that there was a species of shark that lived on the abyssal plains that had not evolved for over 150 million years.
My questions are: -
1. Are there many species around that have ceased to evolve?
2. If so, why do these animals stop evolving when other species continue to change? Have they reached some sort of "perfection"??
BTW, I thoroughly recommend this series, it is absolutely fascinating and the camera work is superb.
"Damn you people. Go back to your shanties." --- Shooter McGavin
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 06/23/2002 : 07:49:20 [Permalink]
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I don't believe that anything ceases to evolve, although many species have slowed it down to next to nothing. Good examples are cockroaches and dragonflies. Also Crocodiles. True, none of these have the tremendous size of yor, but otherwise they all but industinguishable from their ancestors. Not to mention the coalacanth go to www.dinofish.com to see it. Fascinating animal and, aside from the lungfishes, the last of the lobe-fins. It is thought that an ancestor of this fish might be an ancestor of ourselves. The tetrapods evolved from a lobe-fin.
http://www.mc.maricopa.edu/~reffland/anthropology/origins/comingonto.html
luck,
f
Evolution is a bankrupt speculative philosophy, not a scientific fact. Only a spiritually bankrupt society could ever believe it.... Only atheists could accept this Satanic theory. -- Rev. Jimmy Swaggart (source unknown)
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Rift
Skeptic Friend
USA
333 Posts |
Posted - 06/23/2002 : 08:42:33 [Permalink]
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Creatures don't 'cease to evolve'.
This is the big mistake most creationist make when talking about 'stasis'.
A creature, which is in an unchanging environment, won't change. There's no reason for it to change. I suppose you can say it has reached a certain 'perfection', for that environment. Change the environment enough though, and that animal is in trouble. 'stasis' is a kind of an illusion... If there is no change in the environment, there is no reason to 'evolve', although that is an incorrect way of putting it, since things are always being selected for and against, and always evolving. If the same traits are always being selected for and against, you have 'stasis'.
Filthy is right about the Ceolocanth. I would venture to guess that the oceanic abyssal plains and other deep water environments, don't change a heck of a lot. Therefore your shark and the Ceolocanth would have no reason to change either...
Enivironment isn't the only factor, either of course, this is a simplification. A large population that can freely move around won't 'evolve' either, I doubt humans will change much anymore. Small isolated populations change, not large mobile ones.
"Ignorance has caused more calamity then malignity" H.G. Wells |
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Lars_H
SFN Regular
Germany
630 Posts |
Posted - 06/23/2002 : 12:22:00 [Permalink]
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In addition to what has already been said, I'd like to add some stuff about living fossiles.
Also the fossiles of those ancient craetures look a lot like their contemporary descendants, it can not be said that they have stopped to evolve. We don't have any DNA from those long-dead beings to compare today's creatures' DNA with. Just because the outward form has not changed does not mean that the species has not chnaged at all.
The second thing seems like a minor nitpick, but is really one of biggest misunderstandings about evolution. Evoultion is not aimed at anything. Evolution does not try to create a creature perfectly adapted to it's environment. We are not evolving towards perfection and neither is anything else. Evolution will 'change' creatures, so that they have an advantage over their contamporary brothers. This means that they are better adapted then their rivals, not better adapted then ancestors that no longer exist. Evolution does not happen in a straight line, but can wander in circles. Living fossiles might be explained as having evolved in very small circles for a long time.
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The Rat
SFN Regular
Canada
1370 Posts |
Posted - 06/23/2002 : 17:18:07 [Permalink]
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I love David Attenborough, I grew up watching him on the BBC in the late 50's/early 60's. Unfortunately, he seems to have oversimplified this one for the masses.
If you want to check out a fantastic example of an animal with a very old lineage, look at the Tuatara, Sphenodon punctatus. If you saw a picture of one you would probably say, 'So what, a lizard.' NAH! It's so old it's nowhere close to being a lizard. It and a closely related species are the last surviving members of the order Rhynchocephalia, a group which evolved, flourished, and, for the most part, died out before dinosaurs evolved!
Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom. |
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Phobos
New Member
USA
47 Posts |
Posted - 06/24/2002 : 14:31:13 [Permalink]
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As already noted, evolution doesn't stop. I'll just add that I bet the statement that that species of shark "had not evolved for over 150 million years" was a generalization referring to large scale changes. There still should be minute changes from generation to generation. Any sexually-reproducing species reshuffles its gene pool with each new generaton. Plus, they're just looking at gross anatomy (fossils). Some things like evolution of an immune system would be tough to detect from fossils.
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Sixdays
New Member
20 Posts |
Posted - 07/01/2002 : 15:12:35 [Permalink]
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quote:
Creatures don't 'cease to evolve'.
Filthy is right about the Ceolocanth. I would venture to guess that the oceanic abyssal plains and other deep water environments, don't change a heck of a lot. Therefore your shark and the Ceolocanth would have no reason to change either...
What the evolutionist fail to tell us is that plain old simple genetic drift should have changed the coelacanth in the 340 MY's it's been around.
The evolutionist also claim that mutations occur in every species. Certainly after 340 MY's these mutations would have added up in small steps and effected the coelacanth in some morphological fashion to a point where the original no longer exist. There seems to be a bit more than the non-changing environment at work when it comes to evolutionary theory.
My new motto [b]be skeptical about evolution[/b
Six days |
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Slater
SFN Regular
USA
1668 Posts |
Posted - 07/01/2002 : 16:20:04 [Permalink]
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Dorothy: But how can you talk? Scarecrow: I dunno, but it seems to me that some people without brains do an awful lot of talking.
------- My business is to teach my aspirations to conform themselves to fact, not to try and make facts harmonize with my aspirations. ---Thomas Henry Huxley, 1860 |
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The Rat
SFN Regular
Canada
1370 Posts |
Posted - 07/01/2002 : 16:35:33 [Permalink]
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quote:
What the evolutionist fail to tell us is that plain old simple genetic drift should have changed the coelacanth in the 340 MY's it's been around.
It has. I'm not sure how long the entire family has been around, but the first coelacanths would probably have diverged into many different species. All we know now is that they died out, for the most part, at the end of the cretaceous, 65 million years ago. Since then, we have two species. Perhaps only one survived the cretaceous and has diverged again. Regardless, I fail to see how your questions about the coelacanth call evolution itself into doubt.
quote:
The evolutionist also claim that mutations occur in every species. Certainly after 340 MY's these mutations would have added up in small steps and effected the coelacanth in some morphological fashion to a point where the original no longer exist.
Who says the original does? Who ever said it? We say that the two species living today are representative of the family, just as present day horses are representative of the family of perrisodactylans, and are today among the last members of that much diminished group.
quote:
There seems to be a bit more than the non-changing environment at work when it comes to evolutionary theory.
Six days
Where did you get the stupid idea that the environment is 'non-changing'?! If you can produce any evolutionist that says that I will personally kick their narrow ass from St. Johns to Vancouver.
Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom. |
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Antie
Skeptic Friend
USA
101 Posts |
Posted - 07/01/2002 : 16:46:10 [Permalink]
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> My new motto [b]be skeptical about evolution[/b
Why aren't you also skeptical about gravitation? It's also not a "proven fact" and it's "only a theory"! Surely you're not a silly gravitationist, right?
Edited by - antie on 07/01/2002 16:49:22 |
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@tomic
Administrator
USA
4607 Posts |
Posted - 07/01/2002 : 16:49:16 [Permalink]
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You are definately onto something there Antie. Every time I look down at the scale I keep thinking, "That can't be right."
@tomic
Gravity, not just a good idea...it's the law! |
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Antie
Skeptic Friend
USA
101 Posts |
Posted - 07/01/2002 : 16:50:51 [Permalink]
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> You are definately onto something there Antie. Every time I look down > at the scale I keep thinking, "That can't be right."
Well, it's not gravity. Things fall down because the world sucks!
Ian Andreas Miller. DIES GAUDII. |
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The Rat
SFN Regular
Canada
1370 Posts |
Posted - 07/01/2002 : 17:43:32 [Permalink]
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quote: What the evolutionist fail to tell us is that plain old simple genetic drift should have changed the coelacanth in the 340 MY's it's been around.
Six days
http://www.berkeley.edu/news/media/releases/99legacy/10-28-1999.html
It HAS changed, and in significantly less time than 340 million years.
CRASH AND BUUUUUUUUUUUUUUURN, Six days!!!
Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom.
Edited by - The Rat on 07/01/2002 17:45:57 |
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Sixdays
New Member
20 Posts |
Posted - 07/01/2002 : 17:47:24 [Permalink]
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Rift said: A creature, which is in an unchanging environment, won't change. There's no reason for it to change. I suppose you can say it has reached a certain 'perfection', for that environment.
Rat said: Where did you get the stupid idea that the environment is 'non-changing'?! If you can produce any evolutionist that says that I will personally kick their narrow ass
Start runnig Rift, here comes Rat
Six days |
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Sixdays
New Member
20 Posts |
Posted - 07/01/2002 : 17:52:27 [Permalink]
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quote:
quote: What the evolutionist fail to tell us is that plain old simple genetic drift should have changed the coelacanth in the 340 MY's it's been around.
Six days
http://www.berkeley.edu/news/media/releases/99legacy/10-28-1999.html
It HAS changed, and in significantly less time than 340 million years.
CRASH AND BUUUUUUUUUUUUUUURN, Six days!!!
Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom.
Edited by - The Rat on 07/01/2002 17:45:57
You forgot that a currently living coelacanth has been found that looks just like the fossils dated over 300 MY's old.
Would you like a reference?
I'm still flying high
Six days |
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The Rat
SFN Regular
Canada
1370 Posts |
Posted - 07/01/2002 : 18:14:51 [Permalink]
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quote: You forgot that a currently living coelacanth has been found that looks just like the fossils dated over 300 MY's old.
Would you like a reference?
Six days
Sure, I would love a reference. BUT: It must show that the two specimens are IDENTICAL, not "...looks just like..."
Bailey's second law; There is no relationship between the three virtues of intelligence, education, and wisdom. |
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