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Author Topic:   Explanations for the Cambrian Explosion
AlphaOmegakid
Member (Idle past 1135 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 91 of 137 (488044)
11-07-2008 1:16 PM
Reply to: Message 89 by Coyote
11-07-2008 1:07 PM


Re: Index fossils
Wrong. That is a standard creationist talking point, and it is wrong. It shows a deliberate misunderstanding of how these things work.

I know very well how these things work. That doesn't mean that circular reasoning is not present. It clearly is, but it's a red herring to this discussion.


This message is a reply to:
 Message 89 by Coyote, posted 11-07-2008 1:07 PM Coyote has not yet responded

Replies to this message:
 Message 92 by AdminNosy, posted 11-07-2008 1:28 PM AlphaOmegakid has responded

  
AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 92 of 137 (488047)
11-07-2008 1:28 PM
Reply to: Message 91 by AlphaOmegakid
11-07-2008 1:16 PM


New Topic?
It clearly is, but it's a red herring to this discussion.

Half right. It clearly is a red herring. But half wrong, you don't understand how index fossils are used at all so you might learn something if you open a new topic and either ask how it is done (the better way since you don't know) or tell how you think it is circular.

You also don't know what uniformatarianism is either. It is not a good idea to assert so strongly about areas you know so little about.


This message is a reply to:
 Message 91 by AlphaOmegakid, posted 11-07-2008 1:16 PM AlphaOmegakid has responded

Replies to this message:
 Message 96 by AlphaOmegakid, posted 11-07-2008 1:59 PM AdminNosy has responded

  
Coragyps
Member
Posts: 5398
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 93 of 137 (488049)
11-07-2008 1:31 PM
Reply to: Message 90 by AlphaOmegakid
11-07-2008 1:13 PM


Re: Aokidspeak??
is part of catastrophism and not uniformitarianism.

Nope. Erosion and plate tectonics are pretty gradual. You don't need rapid "catastrophes" to dispose of 540,000,000-year-old rock.


"The wretched world lies now under the tyranny of foolishness; things are believed by Christians of such absurdity as no one ever could aforetime induce the heathen to believe." - Agobard of Lyons, ca. 830 AD
This message is a reply to:
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AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 94 of 137 (488050)
11-07-2008 1:38 PM
Reply to: Message 93 by Coragyps
11-07-2008 1:31 PM


Uniformitarianism
:) and you don't know what it is either . :)
This message is a reply to:
 Message 93 by Coragyps, posted 11-07-2008 1:31 PM Coragyps has not yet responded

  
Huntard
Member (Idle past 554 days)
Posts: 2870
From: Limburg, The Netherlands
Joined: 09-02-2008


Message 95 of 137 (488053)
11-07-2008 1:42 PM
Reply to: Message 78 by AlphaOmegakid
11-07-2008 11:28 AM


I thought that was what skeptiks did??

No, sceptics will question the answer, but when all evidence points to something being true, they don't go "I'm still going to say it isn't". That's being stupid, not being a sceptic.

There was? You had better read you article a little better. The Cambrian begins at 545 mya (all dates are evo time).

Evo time? Is that like CET but better? Seriously, I don't know why I even bother....EVO TIME? *sigh*.

The earth is 4500 my old. That means that the preCambrian is 3955 mys of rock layers. The first fossilized signs of life appeared about 2700mya.

Which is WAY before the Cambrian.

hat means 1800mys with nothing but an "evolving planet".

Since planets are not alive, they do not evolve.

The first multicellular "complex" organisms appear about 580mya (just before the Cambrian.)

Yes, these are the ancestors to the ones appearing in the Cambrian.

That means we have nothing but single celled organisms and simple multicellular algaes that were fossilized between 2700mya and 580mya.

Yes, and again, those are the ancestors to the organisms in the Cambrian.

That's 2100mys of simple life with no evidence of evolution.

No evolution? What the hell did you think all those organisms did? They sat there NOT evolving? You do know what evolution is, don't you? In case you forgot, it's the change of hereditary traits in a population over time. You are telling me the genes of all the animals that lived before the Cambrian remained PERFECTLY THE SAME generation after generation?

Sure it is. It's the magic of millions of years.

And as we all know, millions of years actually means "in an instant"

We can have 2100 million years of no evidence of evolution and then all of a sudden "poof" we magically have about a 50 my period when all the phyla of organisms with great complexity appearin the fossil record.

Yes, as pointed out earlier, 50 million years actually means in an instant.

All of them appearing by the early Cambrian.

Yes, this still covers a period of 50 million years. Again, that's not a "poof".

That's a "puntuated evolutionary poof".

A what? ..... Never mind.....

Then I ask you to back this up with evidence. The fossil record is virtually empty for roughly 2100 mys. Please show us the Pre Cambrian transitionals.

You didn't notice the picture in the "Precambrian Life" part? There's two there that I'd say are fossils of things that lived before the Cambrian. You disagree?

We do? Maybe you can specualate about the 2% of vertebrate fossils found, but show me the evolutionary tract of the 98% of fossils which are plants and invertebrates. Pick one and show me how well you can track it.

Pfff, seems like I actually have to put in some work here. Alrgiht, here goes. First of all, the fossil record is but one avenue of research into evolutionary biology. But I suppose I'll make a list for you, not of invertebrates, but it's still quite impressive. (to other readers, sorry, it will be rather long)

First, invertebrate to vertebrate:
1) Pikaia
2) Yunannozoon
3) Haikouella
4) Conodonts
5) Placoderms (these had jaws)

Right, in the fish department now:
6) Cheirolepis
7) Osteolepis (early lobe finned fish, and showing an amfidian like skull)
8) Eusthenopteron (Amfibian skull, and bane and muscle attachments of fins similar as those found in early tetrapod limbs)
9) Panderichthys (very tetrapod like. Has flattened body as well as foot like fins)
10) Acanthostega (fin to foot transition almost complete)

Early tetrapod time!:
11) Tiktaalik (Fins posses wrist and finger bones, and has a neck and both lungs and gills)
12) Ichthyostega (Shoulder and pelvis very tetrapod like and has a very similar rib cage to tetrapods)

Early land amphibians: (By now I would say I can quit, but I'll just keep going)
13) Pteroplax (skull bone patterns similar to Ichthyostega and remnants of gills can be found at the neck)
14) Proterogyrinus (Has amphibian like skull, but limbs and spine have reptilian characteristics)
15) Solenodonsaurus (No more lateral line on the head)
16) Hylonomus &
17) Paleothyris (both small lizard like creatures that still have an amphibian like skull)

Argh! It's the reptilians!:
18) Pelycosaurs (synapsids with differentiated teeth)
19) Therapsids (mamal like reptiles with complex jaws and teeth. Legs vertically attached under their bodies)
20) Proto mamals (whole bunch of 'em, in these we see further development of the skull)

Right, mamal department!:
21) Early placentals (small, rodent like organisms)
22) Phenacolemur Jepseni &
23) Teilhardina Asiatica (Both early primates, whose skulls don't really look like primates, but the teeth are getting there)
24) Amphipitecus &
25) Pondaungia Cotteri (from these fossils we can see the brain size increasing, while the nose was getting shorter)

Ape country!:
26) Propliopithecus Haeckell (teeth became a defining characteristic of apes)
27) Aegyptopithicus Zeuxis (Has larger and "rounder" brain)
28) Proconsul (characteristics of both apes and monkeys, also, sexual dimorphism pops up)
29) Kenyapithecus (descendant from Proconsul, and ancestor to both man and the great apes)
30) Australopithecus Afarensis (ape like, but bipedal)
31) Australopithecus Africanus (larger brain, teeth similar to those found in the "homo" genus)

Which is the next stage (and the final one) Humans!:
32) Homo Habilis (sits on the Australopitecine-Homo boundary. Has larger brain, and used tools)
33) Homo Erectus (Larger brain again, an used fire)
34) Homo Sapiens (Brain between Homo Erectus and Homo Sapiens Sapiens, also much finer teeth then predecessor)
35) Homo Sapiens Sapiens

Nice list eh? yes, those weren't invertebrates. I can give you a clue why there are little fossils of them though. Here goes: "NO HARD PARTS". So, are you saying god made all invertebrates?

The use of index fossils.

Ah yes of course, and because the method used by scientists is completely wrong, they had NO success in predicting where Tiktaalik would be and they haven't found it yet....Oh wait, they have. Sorry, try again.

And what planet do you live on? The Cambrian explosion is by no means a settled issue in science. Did you read your own article? Here are just a few quotes from your article....

I didn't say they weren't arguing about it, I said they had no problem with it regarding evolution.

Uh, That's the definition of a skeptic.

As pointed out in the very first paragraph, it isn't.


I hunt for the truth
This message is a reply to:
 Message 78 by AlphaOmegakid, posted 11-07-2008 11:28 AM AlphaOmegakid has responded

Replies to this message:
 Message 104 by AlphaOmegakid, posted 11-07-2008 3:55 PM Huntard has responded

    
AlphaOmegakid
Member (Idle past 1135 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 96 of 137 (488056)
11-07-2008 1:59 PM
Reply to: Message 92 by AdminNosy
11-07-2008 1:28 PM


Re: New Topic?
You also don't know what uniformatarianism is either. It is not a good idea to assert so strongly about areas you know so little about.

Well maybe with your superior "wisdom" on the topic at hand you can offer a difinitive explanation with evidenc as to why the fossil record is virtually empty of evolutionary evidence for 2100 mys.


This message is a reply to:
 Message 92 by AdminNosy, posted 11-07-2008 1:28 PM AdminNosy has responded

Replies to this message:
 Message 97 by AdminNosy, posted 11-07-2008 2:12 PM AlphaOmegakid has responded
 Message 98 by New Cat's Eye, posted 11-07-2008 2:13 PM AlphaOmegakid has responded

  
AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 97 of 137 (488058)
11-07-2008 2:12 PM
Reply to: Message 96 by AlphaOmegakid
11-07-2008 1:59 PM


Evidence
Well maybe with your superior "wisdom" on the topic at hand you can offer a difinitive explanation with evidenc as to why the fossil record is virtually empty of evolutionary evidence for 2100 mys.

Why don't you read and discuss what you've already been told?


This message is a reply to:
 Message 96 by AlphaOmegakid, posted 11-07-2008 1:59 PM AlphaOmegakid has responded

Replies to this message:
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New Cat's Eye
Inactive Member


Message 98 of 137 (488059)
11-07-2008 2:13 PM
Reply to: Message 96 by AlphaOmegakid
11-07-2008 1:59 PM


Re: New Topic?

Well maybe with your superior "wisdom" on the topic at hand you can offer a difinitive explanation with evidenc as to why the fossil record is virtually empty of evolutionary evidence for 2100 mys.

The organisms didn't have much of the hard parts that lead to a lot of fossilization.


This message is a reply to:
 Message 96 by AlphaOmegakid, posted 11-07-2008 1:59 PM AlphaOmegakid has responded

Replies to this message:
 Message 99 by AlphaOmegakid, posted 11-07-2008 2:26 PM New Cat's Eye has responded

  
AlphaOmegakid
Member (Idle past 1135 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 99 of 137 (488066)
11-07-2008 2:26 PM
Reply to: Message 98 by New Cat's Eye
11-07-2008 2:13 PM


Re: New Topic?
The organisms didn't have much of the hard parts that lead to a lot of fossilization.

Yeah right! That explains the gazillions of soft bodied fossils that do exist in Cambrian and later layers. But none in between 2700mya and 580mya. Why is that?


This message is a reply to:
 Message 98 by New Cat's Eye, posted 11-07-2008 2:13 PM New Cat's Eye has responded

Replies to this message:
 Message 101 by New Cat's Eye, posted 11-07-2008 2:45 PM AlphaOmegakid has not yet responded

  
AlphaOmegakid
Member (Idle past 1135 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 100 of 137 (488070)
11-07-2008 2:31 PM
Reply to: Message 97 by AdminNosy
11-07-2008 2:12 PM


Re: Evidence
Why don't you read and discuss what you've already been told?

Unless you can show otherwise, I have been discussing with multiple people, and I have answered (for the most part given the time) all of their replies. But you have criticized me, yet you offer no substance. You've done this before in other forums. I asked a simple question for someone who is a knowledgeable evolutionist. You have offerred no answer.


This message is a reply to:
 Message 97 by AdminNosy, posted 11-07-2008 2:12 PM AdminNosy has not yet responded

Replies to this message:
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New Cat's Eye
Inactive Member


Message 101 of 137 (488076)
11-07-2008 2:45 PM
Reply to: Message 99 by AlphaOmegakid
11-07-2008 2:26 PM


Re: New Topic?
That explains the gazillions of soft bodied fossils that do exist in Cambrian and later layers. But none in between 2700mya and 580mya.

I think you're mistaken on the numbers of fossils in the different eras...

Why is that?

Here's some quotes from the wiki page on Cambrian Explosion that might help you conseptualize this:

quote:
The Cambrian fossil record includes an unusually high number of lagerstätten, which preserve soft tissues.

quote:
Stromatolites, stubby pillars built by colonies of microorganisms, are a major constituent of the fossil record from about 2,700 million years ago, but their abundance and diversity declined steeply after about 1,250 million years ago. This decline has been attributed to disruption by grazing and burrowing animals.

quote:
Precambrian marine diversity was dominated by small fossils known as acritarchs. This term describes almost any small organic walled fossil – from the egg cases of small metazoans to resting cysts of many different kinds of green algae. After appearing around 2,000 million years ago, acritarchs underwent a boom around 1,000 million years ago, increasing in abundance, diversity, size, complexity of shape and especially size and number of spines.

quote:
The earliest Cambrian trilobite fossils are about 530 million years old, but the class was already quite diverse and worldwide, suggesting that they had been around for quite some time.

quote:
However, evidence of Precambrian metazoa is gradually accumulating. If the Ediacaran Kimberella was a mollusc-like protostome (one of the two main groups of coelomates),[55][17] the protostome and deuterostome lineages must have split significantly before 550 million years ago (deuterostomes are the other main group of coelomates).[73] Even if it is not a protostome, it is widely accepted as a bilaterian.[73][59] Since fossils of rather modern-looking Cnidarians (jellyfish-like organisms) have been found in the Doushantuo lagerstätte, the Cnidarian and bilaterian lineages must have diverged well over 580 million years ago.

quote:
The presence of Precambrian animals somewhat dampens the "bang" of the explosion: not only was the appearance of animals gradual, but their evolutionary radiation ("diversification") may also not have been as rapid as once thought. Indeed, statistical analysis shows that the Cambrian explosion was no faster than any of the other radiations in animals' history.4

There is little doubt that disparity – that is, the range of different organism "designs" or "ways of life" – rose sharply in the early Cambrian.[5] However recent research has overthrown the once-popular idea that disparity was exceptionally high throughout the Cambrian, before subsequently decreasing.[75] In fact, disparity remains relatively low throughout the Cambrian, with modern levels of disparity only attained after the early Ordovician radiation.[5]

The diversity of many Cambrian assemblages is similar to today's.


quote:
Despite the evidence that moderately complex animals (triploblastic bilaterians) existed before and possibly long before the start of the Cambrian, it seems that the pace of evolution was exceptionally fast in the early Cambrian. Possible explanations for this fall into three broad categories: environmental, developmental, and ecological changes. Any explanation must explain the timing and magnitude of the explosion. It is also possible that the "explosion" requires no special explanation.

This message is a reply to:
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NosyNed
Member
Posts: 8860
From: Canada
Joined: 04-04-2003
Member Rating: 4.8


Message 102 of 137 (488078)
11-07-2008 2:52 PM
Reply to: Message 100 by AlphaOmegakid
11-07-2008 2:31 PM


Re: Evidence
I just went over the whole thread. I don't see any answers to what you've been told.

1. The cambrian "explosion" occurred over a time frame comparable to the time between the KT boundary and today. We know what evolved over that time.

2. The various organisms that "suddenly" (see above) appeared would ALL look to the untrained eye like a bunch of slight variation on the "creepy crawly" model. We assign them to different high taxa today but they were not as different from each other as mammals, insects and mollusks are today.

3. There isn't a particular dearth of fossils beyond what one expects when you are looking back for over half a billion years.

4. There are, as of the last few decades, precursors to the cambrian life so it isn't as "sudden" or "mysterious" as it might have been called 50 years ago.

In other words, sem problemas.

You haven't show any hint that you have "got" all this yet.

Meanwhile since you like to pretend to be interested in learning why don't you start to discuss index fossils?


This message is a reply to:
 Message 100 by AlphaOmegakid, posted 11-07-2008 2:31 PM AlphaOmegakid has not yet responded

  
rueh
Member (Idle past 1920 days)
Posts: 382
From: universal city tx
Joined: 03-03-2008


Message 103 of 137 (488088)
11-07-2008 3:51 PM
Reply to: Message 90 by AlphaOmegakid
11-07-2008 1:13 PM


Re: Aokidspeak??
hello AOK.
First off let me say I am sorry if my reply earlier was a little short, been kinda rough week.

AOK writes:

You're suggestion, even though quite logical, is part of catastrophism and not uniformitarianism.

Why would it have to fall under one or the other. I believe it is entirely possible that the Earth has periods of more and less active tetonic movements, while still appearing to have an average movement rate. In which case it is still just a matter of how long ago a life form died and the odds of fossilized remains surviving to this day. With the odds ever decreasing, that older forms of life remain in tact. The odds even with uniformitarianism are still bad when comparing an event that occured 2,100,000,000 years ago to one that happened 500,000,000 years ago.
This message is a reply to:
 Message 90 by AlphaOmegakid, posted 11-07-2008 1:13 PM AlphaOmegakid has not yet responded

  
AlphaOmegakid
Member (Idle past 1135 days)
Posts: 564
From: The city of God
Joined: 06-25-2008


Message 104 of 137 (488090)
11-07-2008 3:55 PM
Reply to: Message 95 by Huntard
11-07-2008 1:42 PM


We do? Maybe you can specualate about the 2% of vertebrate fossils found, but show me the evolutionary tract of the 98% of fossils which are plants and invertebrates. Pick one and show me how well you can track it.

Pfff, seems like I actually have to put in some work here. Alrgiht, here goes. First of all, the fossil record is but one avenue of research into evolutionary biology. But I suppose I'll make a list for you, not of invertebrates, but it's still quite impressive. (to other readers, sorry, it will be rather long)

First, invertebrate to vertebrate:
1) Pikaia
2) Yunannozoon
3) Haikouella
4) Conodonts
5) Placoderms (these had jaws)

Right, in the fish department now:
6) Cheirolepis
7) Osteolepis (early lobe finned fish, and showing an amfidian like skull)
8) Eusthenopteron (Amfibian skull, and bane and muscle attachments of fins similar as those found in early tetrapod limbs)
9) Panderichthys (very tetrapod like. Has flattened body as well as foot like fins)
10) Acanthostega (fin to foot transition almost complete)

Early tetrapod time!:
11) Tiktaalik (Fins posses wrist and finger bones, and has a neck and both lungs and gills)
12) Ichthyostega (Shoulder and pelvis very tetrapod like and has a very similar rib cage to tetrapods)

Early land amphibians: (By now I would say I can quit, but I'll just keep going)
13) Pteroplax (skull bone patterns similar to Ichthyostega and remnants of gills can be found at the neck)
14) Proterogyrinus (Has amphibian like skull, but limbs and spine have reptilian characteristics)
15) Solenodonsaurus (No more lateral line on the head)
16) Hylonomus &
17) Paleothyris (both small lizard like creatures that still have an amphibian like skull)

Argh! It's the reptilians!:
18) Pelycosaurs (synapsids with differentiated teeth)
19) Therapsids (mamal like reptiles with complex jaws and teeth. Legs vertically attached under their bodies)
20) Proto mamals (whole bunch of 'em, in these we see further development of the skull)

Right, mamal department!:
21) Early placentals (small, rodent like organisms)
22) Phenacolemur Jepseni &
23) Teilhardina Asiatica (Both early primates, whose skulls don't really look like primates, but the teeth are getting there)
24) Amphipitecus &
25) Pondaungia Cotteri (from these fossils we can see the brain size increasing, while the nose was getting shorter)

Ape country!:
26) Propliopithecus Haeckell (teeth became a defining characteristic of apes)
27) Aegyptopithicus Zeuxis (Has larger and "rounder" brain)
28) Proconsul (characteristics of both apes and monkeys, also, sexual dimorphism pops up)
29) Kenyapithecus (descendant from Proconsul, and ancestor to both man and the great apes)
30) Australopithecus Afarensis (ape like, but bipedal)
31) Australopithecus Africanus (larger brain, teeth similar to those found in the "homo" genus)

Which is the next stage (and the final one) Humans!:
32) Homo Habilis (sits on the Australopitecine-Homo boundary. Has larger brain, and used tools)
33) Homo Erectus (Larger brain again, an used fire)
34) Homo Sapiens (Brain between Homo Erectus and Homo Sapiens Sapiens, also much finer teeth then predecessor)
35) Homo Sapiens Sapiens

Nice list eh? yes, those weren't invertebrates. I can give you a clue why there are little fossils of them though. Here goes: "NO HARD PARTS". So, are you saying god made all invertebrates?

Yes most evos avoid the invertebrates. I wonder if NosyNed is going to admonish you for your complete lack of knowledge of invertebrates.

You evidently don't know that invertebrates make up 98% of all known species that have been identified. You know how we discovered most of them? They fossilized. Yes, both soft bodied invertebrates and hard bodied invertebrates. Most invertebrates have HARD PARTS. Sorry to inform you of this TINY fact. Many are found in the Cambrian explosion. Both soft bodied fossils and hard bodied fossils. If the Cambrian is full of these diverse phyla and lifeforms, then why zilch before 580mya? Why nothing but single celled organisms and multicelled algae? Then "Poof" a smorgasborg of diverse complex organisms. Organisms with eyes, digestive systems, nervous systems, breathing systems, legs, shells, yet we have no evidence of how these systems evolved from algae and single cells prior to 580mya.


This message is a reply to:
 Message 95 by Huntard, posted 11-07-2008 1:42 PM Huntard has responded

Replies to this message:
 Message 105 by NosyNed, posted 11-07-2008 5:14 PM AlphaOmegakid has responded
 Message 109 by Huntard, posted 11-07-2008 8:24 PM AlphaOmegakid has responded
 Message 115 by Blue Jay, posted 11-08-2008 1:04 PM AlphaOmegakid has responded

  
NosyNed
Member
Posts: 8860
From: Canada
Joined: 04-04-2003
Member Rating: 4.8


Message 105 of 137 (488096)
11-07-2008 5:14 PM
Reply to: Message 104 by AlphaOmegakid
11-07-2008 3:55 PM


so what?
then why zilch before 580mya?

There is NOT zilch! You have to pay attention when you are told something.

Why nothing but single celled organisms and multicelled algae?

For a couple of billion years there was no oxygen in the air. That makes multicellular organisms difficult.

Then it took most of another couple of billion to reach about 10 %. Strangely it was just about this that muliticellular life appeared.

In addition, some selective pressures are needed. The time of snowball earth is conjectured to have supplied such pressure if competition didn't.

...yet we have no evidence of how these systems evolved from algae and single cells prior to 580mya.

Yet.. we do have such evidence. Not a heck of a lot to be sure but it is there.

This is not the total mystery you think it is.

And if it was; so what? Just what does not knowing the detailed how of something mean?


This message is a reply to:
 Message 104 by AlphaOmegakid, posted 11-07-2008 3:55 PM AlphaOmegakid has responded

Replies to this message:
 Message 106 by AlphaOmegakid, posted 11-07-2008 6:08 PM NosyNed has responded

  
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