The Cambrian Explosion

[achilles12604]

Besides the apologist answer that God was responsible for this phenomina by some method, does secular science have a theory as to the cause of this sudden explosion of new life all at once? (Remember I do not fall for that God of Gaps theory)

I am looking for science answer to this mystery. Anyone care to enlighten me?

[Galphanore]

I realise that the commonly accepted claim is that they all developed in the Cambrian, but I think this is far more likely to be a rote repetition then an actual observation, especially considering that even without re-ordering that chart or including the plant phylum it clearly shows that they were not.

You're not saying that evolutionists are all saying something by rote repetition even though it could be wrong are you? Impossible!

You're hardly one to talk. Not everyone is an expert on everything, and not all experts bother to look into something that's taught as an observable phenomena. Evolution it's self is observable, what is being questioned here is labels, nothing more. We labeled the phylum based on things we saw around us, and then someone noticed there were a number of them originating in the Cambrian, so they labeled it the Cambrian explosion and made the claim that the phylum originated there. We've sense seen otherwise, most people just havn't noticed yet.

[otseng]

I realise that the commonly accepted claim is that they all developed in the Cambrian, but I think this is far more likely to be a rote repetition then an actual observation, especially considering that even without re-ordering that chart or including the plant phylum it clearly shows that they were not.

You're not saying that evolutionists are all saying something by rote repetition even though it could be wrong are you? Impossible!

You're hardly one to talk.

(Hmm, I think I should've used a smilie there.)

Not sure what "I'm hardly one to talk" is implying. But, I certainly do not claim to be an expert on anything. I'm more of just an inquisitive observer.

We labeled the phylum based on things we saw around us, and then someone noticed there were a number of them originating in the Cambrian, so they labeled it the Cambrian explosion and made the claim that the phylum originated there. We've sense seen otherwise, most people just havn't noticed yet.

I think the dialogue on labels won't produce much more fruitful discussions. I'll start researching on exactly what fossils are found in the Cambrian layer.

[Galphanore]

(Hmm, I think I should've used a smilie there.)

Not sure what "I'm hardly one to talk" is implying. But, I certainly do not claim to be an expert on anything. I'm more of just an inquisitive observer.

Yeah, I should have used a smilie there too. I was just implying that the majority of the people who claim that there are limits on how much change evolution can accomplish base their opinions on the opinions of other people who have barely any understanding of evolution. I shouldn't have said that though, because you are considerably more open minded then most of them. I guess that's why it bugs me so much that you keep implying that macroevolution can't happen.

I think the dialogue on labels won't produce much more fruitful discussions. I'll start researching on exactly what fossils are found in the Cambrian layer.

Ok

[otseng]

OK, I spent some time researching into the claim by Morton that not all the phylum appeared in the Cambrian. Morton presented a table that the phyla appear across different stratas. Morton used as his source the Chart of First Appearances of Metazoans.

I'll present the chart below for ease of reference:



If we look at this chart, it does indeed seem to infer that phyla are found throughout the stratas, with concentrations at the Cambrian and the Cenozoic.

But, on deeper research, this graph is a bit erroneous.

Cnidaria through Bryozoa are within or close to the Cambrian, so I'm not going to comment on those.

Let's look at the rest:

Ctenophora

• three species, Ctenorhabdotus capulus, Fasciculus vesanus and Xanioascus canadensis, are known from the Cambrian Burgess Shale.

  http://en.wikipedia.org/wiki/Ctenophore
  
  So, Ctenophora is in the Cambrian.

Nematoda

• Fossil nematodes have been found in rocks from as early as the Carboniferous. Most living roundworms are microscopic, meaning that their discovery as fossils is likely to be difficult. On the other hand, one species of parasitic nematode can reach 13 meters in length -- it parasitizes the sperm whale. Nematodes also lack any substantial hard parts, again resulting in a spotty chance for fossilization. Despite these problems, fossil nematodes are occasionally found in amber (fossilized tree resin) from the Cenozoic. Because many of their relatives have left fossils dating from the Cambrian, it is likely that the nematodes have been around at least that long in some form.

  http://www.ucmp.berkeley.edu/phyla/ecdy ... atoda.html
  
  It'd be hard to make any definitive statements about this, but Cambrian origin is not out of the question.

Nemertea

• The fossil record of nemerteans is extremely sparse, as would be expected from a soft-bodied animal. The Cambrian fossil, Amiskwia, has been interpreted as a nemertean based on its resemblance to some pelagic ribbon worms; however, this interpretation is disputed by many paleontologists.

  http://en.wikipedia.org/wiki/Enopla
  
  Hard to say also, but there is evidence for Cambrian origin.

Echiura

• The Echiura fossilise poorly and the earliest known specimen is from the Pennsylvanian (called the Upper Carboniferous outside North America). However, U-shaped fossil burrows that could be Echiuran have been found dating back to the Cambrian.

  http://en.wikipedia.org/wiki/Echiura
  Again, hard to make any definitive statements.

Entoprocta

• Could not find much information on it except that it is a filter feeder and less than 5 mm in size.

Rotifera

• Because of their small size (0.1-0.5 mm long), I can't imagine finding any fossiled evidence of this. So, it's interesting that on the chart it is placed in the Cenozoic column.

Nematomorpha

• Three species have been found in the Maotianshan shales:
  Cricocosmia jinningensis
  Maotianshania cylindrica
  Palaeoscolex sinensis
  http://en.wikipedia.org/wiki/Maotianshan_shales
  
  So, the chart is incorrect.

Placozoa

• Fossil placozoans have yet to be discovered, so it should not be placed in Cenozoic.
  
  http://www.ucmp.berkeley.edu/phyla/plac ... cozoa.html

Mesozoa

• Mesozoa is not on the Wikipedia Phylum list. But, even so, no Mesozoan fossils have been found.
  http://www.earthlife.net/inverts/mesozoa.html
  
  So, again, this should not be placed in Cenozoic.

Platyhelminths

• Platyhelminths have practically no fossil record. Also, it is one of the most simplest animals, so there is no reason to say it is in the Cenozoic.
  
  http://www.ucmp.berkeley.edu/platyhelmi ... nthes.html

Gnathostomulida

• Gnathostomulids have no fossil record.
  
  http://en.wikipedia.org/wiki/Gnathostomulida

Gastrotricha

• It is a microscopic animal that lives for 3 days. I can't believe they found a fossil of this in the Cenozoic period (or any period).

Acanthocephala

• Acanthocephala is a parasitic worm. Again, someone is going to have to prove that this was found in the Cenozoic period.

Loricifera

• Loricifera has no fossil record.
  
  http://en.wikipedia.org/wiki/Loricifera

Kinorhyncha

• Kinorhyncha has no fossil record.
  
  http://www.ucmp.berkeley.edu/phyla/ecdy ... yncha.html

Pogonophora

• Pogonophora is not on the Wikipedia Phylum list.
  
  And as a deep sea worm, finding it would be geographically restrictive. Plus, have there been any fossils found of it?

Sipuncula

• Early Cambrian sipunculan worms from southwest China.
  
  Should be in the Cambrian.

Phoronida

• Been found in the Maotianshan Shales.
  
  Should be in the Cambrian.

Urochordata

• Not in Wikipedia Phylum list either.
  
  They also have a sparse fossil record.
  http://www.ucmp.berkeley.edu/chordata/urochordata.html

So, based on my research, there is no reason to doubt what the vast majority of biologists claim in that all the phyla appear during the Cambrian Explosion.

[Galphanore]

Perhaps. Though I still think it would be far more accurate to say "Many of the Phyla developed in the Cambrian", because it still is predicated upon the use of our pre-defined fifty or so phyla instead of allowing each new body plan it's own, which is understandably avoided. It should also be noted that the beginning of the Cambrian is marked by the end of a major Ice-Age and a tipping point at which molecular life forms had released enough free oxygen into the atmosphere to allow larger life-forms to develop. There are actually a great many reasons why a large variety of life forms would develop in a relatively short period of time then.

[Confused]

Besides the apologist answer that God was responsible for this phenomina by some method, does secular science have a theory as to the cause of this sudden explosion of new life all at once? (Remember I do not fall for that God of Gaps theory)

I am looking for science answer to this mystery. Anyone care to enlighten me?

Late joining here, Sorry.

Of all mentioned, I am surprised none have mention the precambrian marine Doushantou fossils found in China.

http://en.wikipedia.org/wiki/Doushantuo_Formation

Doushantuo Formation
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The Doushantuo Formation is a lagerstätte in Guizhou Province, China that is notable for being one of the oldest fossil beds to contain highly preserved fossils. The formation is of particular interest because it appears to cover the boundary between the problematic organisms of the Ediacaran geological period and the more famous Cambrian Explosion. Taken as a whole, the Doushantuo Formation ranges from about 590 Ma at its base to about 565 Ma at its top, predating by perhaps five million years (Ma) the earliest of the 'classical' Ediacaran faunas from Mistaken Point, Newfoundland, and recording conditions a good forty to fifty million years before the Cambrian explosion.

Doushantuo fossils are all marine, microscopic, and highly preserved. The latter two characteristics mean that the structure of the organisms that made them can be studied at the cellular level, and considerable insight has been gained into the embryonic and larval stages of many early creatures. One contentious claim is that many of the fossils show signs of bilateral symmetry, a common feature in many modern-day animals which is usually assumed to have evolved during the later Cambrian Explosion. A nearly microscopic fossil animal, Vernanimalcula ("springtime micro-animal") was announced in October 2005, with the claim that it was the oldest known bilateral animal. However, the absence of adult forms of almost all animal types in the Doushantuo (there are microscopic adult sponges and corals) makes these claims difficult to prove: some argue that their lack suggests these finds are not larval and embryonic forms at all; supporters contend that some unidentified process "filtered out" all but the smallest forms from fossilization.

The discovery was made when the rich phosphate deposits were being mined, and was first reported in 1998. The finds offer direct evidence that confirms expectations that major evolutionary diversification of animals already had occurred before the onset of the Cambrian period, with its apparent 'explosion' of metazoan life-forms and, therefore, that more remote ancestral forms of the phyla recognizable in Cambrian macrofossils must have existed previously.

Documented biota now includes phosphatized microfossils of algae, multicellular thallophytes (seaweeds), acritarchs, and cyanophytes, besides adult sponges and adult cnidarians, which may include early forms of tabulate corals. There also seem to be what scientists cautiously report as bilateral animal embryos. Some of the possible animal embryos are in an early stage of cellular division that was first interpreted as spores or algal cells, including eggs and embryos which are most probably of sponges or cnidarians, as well as adult sponges, a variety of adult cnidarians, and putative embryos of bilateral animals

While I know this gives credence to creationists theory because it would indeed imply that marine life predated land life, it could also support the theory that land life evolved from marine life. This is not my strongest area: though it is stronger than politics. But if the cambrian did indeed occur as postulated: It need not be a divine influence, but more likely a climate change that forced evolution. I would be interested to be alive should the climate shift as it did in the movie "Absolute Zero". Should it have been climate shift that led to adaptation and evolution, I would be interested to see what lies beneath the antarctic. I think if anything has the greatest chance of leading us to greater leaps of evolution, it will be found at the poles.

But that is just my opinion.

[otseng]

It should also be noted that the beginning of the Cambrian is marked by the end of a major Ice-Age.

Are you referring to Snowball Earth?

[Galphanore]

It should also be noted that the beginning of the Cambrian is marked by the end of a major Ice-Age.

Are you referring to Snowball Earth?

Maybe, not too sure, just something I saw as I was looking into it. Didn't realise it was called "The Snowball Earth Theory".

[otseng]

Well, if it is Snowball Earth, then it goes to show again that anything can be accepted by scientists as long as it's not found in the Bible.

Scientists laugh at the whole world covered by water, but can accept the entire world (or most of it) covered by ice. I would bet that if the Bible had said the whole world was covered by ice, then scientists could accept it was all covered by water.

To be honest, this is the first time I've heard of the Snowball Earth hypothesis. But, it'll make a good debate topic.

[Galphanore]

Well, if it is Snowball Earth, then it goes to show again that anything can be accepted by scientists as long as it's not found in the Bible.

Scientists laugh at the whole world covered by water, but can accept the entire world (or most of it) covered by ice. I would bet that if the Bible had said the whole world was covered by ice, then scientists could accept it was all covered by water.

That's not entirely accurate. For a long time the scientific comunity not only did believe in the biblical flood, but was actually funded by Christian institutions. They've just sense found evidence that has convined them it's not quite as accurate as they thought.

To be honest, this is the first time I've heard of the Snowball Earth hypothesis. But, it'll make a good debate topic.

Not really, it was a passing part of one possible explaination, but it's obiviously been shown to be inaccurate. Also, I did not say the planet it's self was frozen, I said a precambrian ice-age. Which is what I'd read, not this frozen chunk thing.