The 'Bestiary': The Burgess Shale

[Steven_R]

Sudden in this case meaning over the course of 50 million years.

This material is covered in any undergraduate evolutionary biology course. Instead of just relying on the DiscoTute to spoonfeed you the information you want to hear, go take a class or two.

 

[Alfalfa]

"... in 1859 Charles Darwin discussed it as one of the main objections that could be made against his theory of evolution by natural selection..."

All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years. Geology, genetics, chemistry were all in their infancy when Darwin did his work Those generations of biologists since then answered those questions Darwin had. It's no different than Newton not being able to how to understand the perihelion of Mercury in relation to the work he did with calculus. It took two centuries before Einstein could answer that question. It took another three-quarters of a century before Peter Higgs picked up where Einstein left off.

Science is constant discovery and refinement. The answers rarely, if ever, fall into place as a complete picture in one fell swoop.

"All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years."


Could you provide a few of the explanations for Darwin's lacunae that are clear today?

Can you answer the query of the OP:
How, then, does this fit with Darwin's theory of gradual change which would be indicated by innumerable false starts and biological dead ends, indicating failures of random alterations?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.



In truth, you cannot answer the question, nor can contemporary evolutionary theory.


Another question?
Why do you make stuff up when it is so very easy to show you are no more than a source of hot air?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.

Possible causes of the “explosion”

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.
Changes in the environment
Ozone formation

The amount of ozone required to shield Earth from biologically lethal UV radiation, wavelengths from 200 to 300 nanometers (nm), is believed to have been in existence around the Cambrian Explosion. The presence of the ozone formation enables the development of complex life and live on land, as opposed to life being restricted in the water.
Increase in oxygen levels

Earth’s earliest atmosphere contained no free oxygen; the oxygen that animals breathe today, both in the air and dissolved in water, is the product of billions of years of photosynthesis. As a general trend, the concentration of oxygen in the atmosphere has risen gradually over about the last 2.5 billion years.[12]

The shortage of oxygen might well have prevented the rise of large, complex animals. The amount of oxygen an animal can absorb is largely determined by the area of its oxygen-absorbing surfaces (lungs and gills in the most complex animals; the skin in less complex ones); but, the amount needed is determined by its volume, which grows faster than the oxygen-absorbing area if an animal’s size increases equally in all directions. An increase in the concentration of oxygen in air or water would increase the size to which an organism could grow without its tissues becoming starved of oxygen. However, members of the Ediacara biota reached metres in length tens of millions of years before the Cambrian explosion.[33] Other metabolic functions may have been inhibited by lack of oxygen, for example the construction of tissue such as collagen, required for the construction of complex structures,[104] or to form molecules for the construction of a hard exoskeleton.[105] However, animals are not affected when similar oceanographic conditions occur in the Phanerozoic; there is no convincing correlation between oxygen levels and evolution, so oxygen may have been no more a prerequisite to complex life than liquid water or primary productivity.[106]
Snowball Earth
Main article: Snowball Earth

In the late Neoproterozoic (extending into the early Ediacaran period), the Earth suffered massive glaciations in which most of its surface was covered by ice. This may have caused a mass extinction, creating a genetic bottleneck; the resulting diversification may have given rise to the Ediacara biota, which appears soon after the last "Snowball Earth" episode.[107] However, the snowball episodes occurred a long time before the start of the Cambrian, and it is hard to see how so much diversity could have been caused by even a series of bottlenecks;[21] the cold periods may even have delayed the evolution of large size organisms.[44]
Increase in the calcium concentration of the Cambrian seawater

Newer research suggests that volcanically active midocean ridges caused a massive and sudden surge of the calcium concentration in the oceans, making it possible for marine organisms to build skeletons and hard body parts.[108] Alternatively a high influx of ions could have been provided by the widespread erosion that produced Powell's Great Unconformity.[109]
Developmental explanations

A range of theories are based on the concept that minor modifications to animals' development as they grow from embryo to adult may have been able to cause very large changes in the final adult form. The Hox genes, for example, control which organs individual regions of an embryo will develop into. For instance, if a certain Hox gene is expressed, a region will develop into a limb; if a different Hox gene is expressed in that region (a minor change), it could develop into an eye instead (a phenotypically major change).

Such a system allows a large range of disparity to appear from a limited set of genes, but such theories linking this with the explosion struggle to explain why the origin of such a development system should by itself lead to increased diversity or disparity. Evidence of Precambrian metazoans[21] combines with molecular data[110] to show that much of the genetic architecture that could feasibly have played a role in the explosion was already well established by the Cambrian.

This apparent paradox is addressed in a theory that focuses on the physics of development. It is proposed that the emergence of simple multicellular forms provided a changed context and spatial scale in which novel physical processes and effects were mobilized by the products of genes that had previously evolved to serve unicellular functions. Morphological complexity (layers, segments, lumens, appendages) arose, in this view, by self-organization.[111]
Ecological explanations

These focus on the interactions between different types of organism. Some of these hypotheses deal with changes in the food chain; some suggest arms races between predators and prey, and others focus on the more general mechanisms of coevolution. Such theories are well suited to explaining why there was a rapid increase in both disparity and diversity, but they must explain why the "explosion" happened when it did.[21]
End-Ediacaran mass extinction
Main article: End-Ediacaran extinction

Evidence for such an extinction includes the disappearance from the fossil record of the Ediacara biota and shelly fossils such as Cloudina, and the accompanying perturbation in the δ13C record.

Mass extinctions are often followed by adaptive radiations as existing clades expand to occupy the ecospace emptied by the extinction. However, once the dust had settled, overall disparity and diversity returned to the pre-extinction level in each of the Phanerozoic extinctions.[21]
Evolution of eyes
Main article: Evolution of the eye

Andrew Parker has proposed that predator-prey relationships changed dramatically after eyesight evolved. Prior to that time, hunting and evading were both close-range affairs – smell, vibration, and touch were the only senses used. When predators could see their prey from a distance, new defensive strategies were needed. Armor, spines, and similar defenses may also have evolved in response to vision. He further observed that, where animals lose vision in unlighted environments such as caves, diversity of animal forms tends to decrease.[112] Nevertheless, many scientists doubt that vision could have caused the explosion. Eyes may well have evolved long before the start of the Cambrian.[113] It is also difficult to understand why the evolution of eyesight would have caused an explosion, since other senses, such as smell and pressure detection, can detect things at a greater distance in the sea than sight can; but the appearance of these other senses apparently did not cause an evolutionary explosion.[21]
Arms races between predators and prey

The ability to avoid or recover from predation often makes the difference between life and death, and is therefore one of the strongest components of natural selection. The pressure to adapt is stronger on the prey than on the predator: if the predator fails to win a contest, it loses a meal; if the prey is the loser, it loses its life.[114]

But, there is evidence that predation was rife long before the start of the Cambrian, for example in the increasingly spiny forms of acritarchs, the holes drilled in Cloudina shells, and traces of burrowing to avoid predators. Hence, it is unlikely that the appearance of predation was the trigger for the Cambrian "explosion", although it may well have exhibited a strong influence on the body forms that the "explosion" produced.[44] However, the intensity of predation does appear to have increased dramatically during the Cambrian[115] as new predatory "tactics" (such as shell-crushing) emerged.[116]
Increase in size and diversity of planktonic animals

Geochemical evidence strongly indicates that the total mass of plankton has been similar to modern levels since early in the Proterozoic. Before the start of the Cambrian, their corpses and droppings were too small to fall quickly towards the seabed, since their drag was about the same as their weight. This meant they were destroyed by scavengers or by chemical processes before they reached the sea floor.[28]

Mesozooplankton are plankton of a larger size. Early Cambrian specimens filtered microscopic plankton from the seawater. These larger organisms would have produced droppings and corpses that were large enough to fall fairly quickly. This provided a new supply of energy and nutrients to the mid-levels and bottoms of the seas, which opened up a huge range of new possible ways of life. If any of these remains sank uneaten to the sea floor they could be buried; this would have taken some carbon out of circulation, resulting in an increase in the concentration of breathable oxygen in the seas (carbon readily combines with oxygen).[28]

The initial herbivorous mesozooplankton were probably larvae of benthic (seafloor) animals. A larval stage was probably an evolutionary innovation driven by the increasing level of predation at the seafloor during the Ediacaran period.[3][117]

Metazoans have an amazing ability to increase diversity through coevolution.[4] This means that an organism's traits can lead to traits evolving in other organisms; a number of responses are possible, and a different species can potentially emerge from each one. As a simple example, the evolution of predation may have caused one organism to develop a defence, while another developed motion to flee. This would cause the predator lineage to split into two species: one that was good at chasing prey, and another that was good at breaking through defences. Actual coevolution is somewhat more subtle, but, in this fashion, great diversity can arise: three quarters of living species are animals, and most of the rest have formed by coevolution with animals.[4]
Ecosystem engineering

Evolving organisms inevitably change the environment they evolve in. The Devonian colonization of land had planet-wide consequences for sediment cycling and ocean nutrients, and was likely linked to the Devonian mass extinction. A similar process may have occurred on smaller scales in the oceans, with, for example, the sponges filtering particles from the water and depositing them in the mud in a more digestible form; or burrowing organisms making previously unavailable resources available for other organisms.[118]

 

[PoliticalChic]

Sudden in this case meaning over the course of 50 million years.

This material is covered in any undergraduate evolutionary biology course. Instead of just relying on the DiscoTute to spoonfeed you the information you want to hear, go take a class or two.

I'm going to guess that you are a product of government schools, and that you are too weak minded to see the propaganda for what it is....
...and too cowardly to question the purveyors of the propaganda.


Seems that after the indoctrination, you've been "Pavloved" into leaping to the defense of the several materialist doctrines that they demand you defend.


Or....you're just simple-minded.





Darwinian theory is based on the accumulation of random mutations. Some make the organism better equipped to survive....some don't.
But even if the line dies out.....there would be evidence of same in the fossil record.

Even Darwin agreed.
And he wondered why he couldn't find evidence of the new organisms found seemingly fully formed, in the Cambrian.


Yet when the fossil evidence, or lack of same, is brought up, morons like you have as your only answer: "...the DiscoTute to spoonfeed you the information you want to hear..."




Now....which of my earlier suggestions about you explain this?

You accept the propaganda unquestioningly?

You are a coward?

Or...you are just simple-minded.


Be honest.....confession is good for the soul.

 

[PoliticalChic]

All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years. Geology, genetics, chemistry were all in their infancy when Darwin did his work Those generations of biologists since then answered those questions Darwin had. It's no different than Newton not being able to how to understand the perihelion of Mercury in relation to the work he did with calculus. It took two centuries before Einstein could answer that question. It took another three-quarters of a century before Peter Higgs picked up where Einstein left off.

Science is constant discovery and refinement. The answers rarely, if ever, fall into place as a complete picture in one fell swoop.

"All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years."


Could you provide a few of the explanations for Darwin's lacunae that are clear today?

Can you answer the query of the OP:
How, then, does this fit with Darwin's theory of gradual change which would be indicated by innumerable false starts and biological dead ends, indicating failures of random alterations?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.



In truth, you cannot answer the question, nor can contemporary evolutionary theory.


Another question?
Why do you make stuff up when it is so very easy to show you are no more than a source of hot air?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.

Possible causes of the “explosion”

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.
Changes in the environment
Ozone formation

The amount of ozone required to shield Earth from biologically lethal UV radiation, wavelengths from 200 to 300 nanometers (nm), is believed to have been in existence around the Cambrian Explosion. The presence of the ozone formation enables the development of complex life and live on land, as opposed to life being restricted in the water.
Increase in oxygen levels

Earth’s earliest atmosphere contained no free oxygen; the oxygen that animals breathe today, both in the air and dissolved in water, is the product of billions of years of photosynthesis. As a general trend, the concentration of oxygen in the atmosphere has risen gradually over about the last 2.5 billion years.[12]

The shortage of oxygen might well have prevented the rise of large, complex animals. The amount of oxygen an animal can absorb is largely determined by the area of its oxygen-absorbing surfaces (lungs and gills in the most complex animals; the skin in less complex ones); but, the amount needed is determined by its volume, which grows faster than the oxygen-absorbing area if an animal’s size increases equally in all directions. An increase in the concentration of oxygen in air or water would increase the size to which an organism could grow without its tissues becoming starved of oxygen. However, members of the Ediacara biota reached metres in length tens of millions of years before the Cambrian explosion.[33] Other metabolic functions may have been inhibited by lack of oxygen, for example the construction of tissue such as collagen, required for the construction of complex structures,[104] or to form molecules for the construction of a hard exoskeleton.[105] However, animals are not affected when similar oceanographic conditions occur in the Phanerozoic; there is no convincing correlation between oxygen levels and evolution, so oxygen may have been no more a prerequisite to complex life than liquid water or primary productivity.[106]
Snowball Earth
Main article: Snowball Earth

In the late Neoproterozoic (extending into the early Ediacaran period), the Earth suffered massive glaciations in which most of its surface was covered by ice. This may have caused a mass extinction, creating a genetic bottleneck; the resulting diversification may have given rise to the Ediacara biota, which appears soon after the last "Snowball Earth" episode.[107] However, the snowball episodes occurred a long time before the start of the Cambrian, and it is hard to see how so much diversity could have been caused by even a series of bottlenecks;[21] the cold periods may even have delayed the evolution of large size organisms.[44]
Increase in the calcium concentration of the Cambrian seawater

Newer research suggests that volcanically active midocean ridges caused a massive and sudden surge of the calcium concentration in the oceans, making it possible for marine organisms to build skeletons and hard body parts.[108] Alternatively a high influx of ions could have been provided by the widespread erosion that produced Powell's Great Unconformity.[109]
Developmental explanations

A range of theories are based on the concept that minor modifications to animals' development as they grow from embryo to adult may have been able to cause very large changes in the final adult form. The Hox genes, for example, control which organs individual regions of an embryo will develop into. For instance, if a certain Hox gene is expressed, a region will develop into a limb; if a different Hox gene is expressed in that region (a minor change), it could develop into an eye instead (a phenotypically major change).

Such a system allows a large range of disparity to appear from a limited set of genes, but such theories linking this with the explosion struggle to explain why the origin of such a development system should by itself lead to increased diversity or disparity. Evidence of Precambrian metazoans[21] combines with molecular data[110] to show that much of the genetic architecture that could feasibly have played a role in the explosion was already well established by the Cambrian.

This apparent paradox is addressed in a theory that focuses on the physics of development. It is proposed that the emergence of simple multicellular forms provided a changed context and spatial scale in which novel physical processes and effects were mobilized by the products of genes that had previously evolved to serve unicellular functions. Morphological complexity (layers, segments, lumens, appendages) arose, in this view, by self-organization.[111]
Ecological explanations

These focus on the interactions between different types of organism. Some of these hypotheses deal with changes in the food chain; some suggest arms races between predators and prey, and others focus on the more general mechanisms of coevolution. Such theories are well suited to explaining why there was a rapid increase in both disparity and diversity, but they must explain why the "explosion" happened when it did.[21]
End-Ediacaran mass extinction
Main article: End-Ediacaran extinction

Evidence for such an extinction includes the disappearance from the fossil record of the Ediacara biota and shelly fossils such as Cloudina, and the accompanying perturbation in the δ13C record.

Mass extinctions are often followed by adaptive radiations as existing clades expand to occupy the ecospace emptied by the extinction. However, once the dust had settled, overall disparity and diversity returned to the pre-extinction level in each of the Phanerozoic extinctions.[21]
Evolution of eyes
Main article: Evolution of the eye

Andrew Parker has proposed that predator-prey relationships changed dramatically after eyesight evolved. Prior to that time, hunting and evading were both close-range affairs – smell, vibration, and touch were the only senses used. When predators could see their prey from a distance, new defensive strategies were needed. Armor, spines, and similar defenses may also have evolved in response to vision. He further observed that, where animals lose vision in unlighted environments such as caves, diversity of animal forms tends to decrease.[112] Nevertheless, many scientists doubt that vision could have caused the explosion. Eyes may well have evolved long before the start of the Cambrian.[113] It is also difficult to understand why the evolution of eyesight would have caused an explosion, since other senses, such as smell and pressure detection, can detect things at a greater distance in the sea than sight can; but the appearance of these other senses apparently did not cause an evolutionary explosion.[21]
Arms races between predators and prey

The ability to avoid or recover from predation often makes the difference between life and death, and is therefore one of the strongest components of natural selection. The pressure to adapt is stronger on the prey than on the predator: if the predator fails to win a contest, it loses a meal; if the prey is the loser, it loses its life.[114]

But, there is evidence that predation was rife long before the start of the Cambrian, for example in the increasingly spiny forms of acritarchs, the holes drilled in Cloudina shells, and traces of burrowing to avoid predators. Hence, it is unlikely that the appearance of predation was the trigger for the Cambrian "explosion", although it may well have exhibited a strong influence on the body forms that the "explosion" produced.[44] However, the intensity of predation does appear to have increased dramatically during the Cambrian[115] as new predatory "tactics" (such as shell-crushing) emerged.[116]
Increase in size and diversity of planktonic animals

Geochemical evidence strongly indicates that the total mass of plankton has been similar to modern levels since early in the Proterozoic. Before the start of the Cambrian, their corpses and droppings were too small to fall quickly towards the seabed, since their drag was about the same as their weight. This meant they were destroyed by scavengers or by chemical processes before they reached the sea floor.[28]

Mesozooplankton are plankton of a larger size. Early Cambrian specimens filtered microscopic plankton from the seawater. These larger organisms would have produced droppings and corpses that were large enough to fall fairly quickly. This provided a new supply of energy and nutrients to the mid-levels and bottoms of the seas, which opened up a huge range of new possible ways of life. If any of these remains sank uneaten to the sea floor they could be buried; this would have taken some carbon out of circulation, resulting in an increase in the concentration of breathable oxygen in the seas (carbon readily combines with oxygen).[28]

The initial herbivorous mesozooplankton were probably larvae of benthic (seafloor) animals. A larval stage was probably an evolutionary innovation driven by the increasing level of predation at the seafloor during the Ediacaran period.[3][117]

Metazoans have an amazing ability to increase diversity through coevolution.[4] This means that an organism's traits can lead to traits evolving in other organisms; a number of responses are possible, and a different species can potentially emerge from each one. As a simple example, the evolution of predation may have caused one organism to develop a defence, while another developed motion to flee. This would cause the predator lineage to split into two species: one that was good at chasing prey, and another that was good at breaking through defences. Actual coevolution is somewhat more subtle, but, in this fashion, great diversity can arise: three quarters of living species are animals, and most of the rest have formed by coevolution with animals.[4]
Ecosystem engineering

Evolving organisms inevitably change the environment they evolve in. The Devonian colonization of land had planet-wide consequences for sediment cycling and ocean nutrients, and was likely linked to the Devonian mass extinction. A similar process may have occurred on smaller scales in the oceans, with, for example, the sponges filtering particles from the water and depositing them in the mud in a more digestible form; or burrowing organisms making previously unavailable resources available for other organisms.[118]

Much better!

An actual attempt to respond.

Unfortunately, it doesn't respond to the question posed by the OP.
Possibly you had some other OP in mind...this one: "how to explain the sudden rise of such extensive diversity during the Cambrian?"


My question was, why are there no fossil trails culminating in the new organisms found in the Cambrian?


Get it?

Not, why did new organisms result....but where is the proof that they were the result of a series of changes?



Again:

a. Steven J. Gould reported: "In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and fully formed." (Natural History, 86:12-16)

b. "And let us dispose of a common misconception. The complete transmutation of even one animal species into a different species has never been directly observed either in the laboratory or in the field."
Dean H. Kenyon (Professor of Biology, San Francisco State University), affidavit presented to the U.S. Supreme Court, No. 85-1513, Brief of Appellants, prepared under the direction of William J. Guste, Jr., Attorney General of the State of Louisiana, October 1985, p. A-16.



Do you see the problem?
There is no evidence of one species becoming another....and this is the basis of evolution.



Care to take another shot?

 

[PoliticalChic]

All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years. Geology, genetics, chemistry were all in their infancy when Darwin did his work Those generations of biologists since then answered those questions Darwin had. It's no different than Newton not being able to how to understand the perihelion of Mercury in relation to the work he did with calculus. It took two centuries before Einstein could answer that question. It took another three-quarters of a century before Peter Higgs picked up where Einstein left off.

Science is constant discovery and refinement. The answers rarely, if ever, fall into place as a complete picture in one fell swoop.

"All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years."


Could you provide a few of the explanations for Darwin's lacunae that are clear today?

Can you answer the query of the OP:
How, then, does this fit with Darwin's theory of gradual change which would be indicated by innumerable false starts and biological dead ends, indicating failures of random alterations?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.



In truth, you cannot answer the question, nor can contemporary evolutionary theory.


Another question?
Why do you make stuff up when it is so very easy to show you are no more than a source of hot air?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.

Possible causes of the “explosion”

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.
Changes in the environment
Ozone formation

The amount of ozone required to shield Earth from biologically lethal UV radiation, wavelengths from 200 to 300 nanometers (nm), is believed to have been in existence around the Cambrian Explosion. The presence of the ozone formation enables the development of complex life and live on land, as opposed to life being restricted in the water.
Increase in oxygen levels

Earth’s earliest atmosphere contained no free oxygen; the oxygen that animals breathe today, both in the air and dissolved in water, is the product of billions of years of photosynthesis. As a general trend, the concentration of oxygen in the atmosphere has risen gradually over about the last 2.5 billion years.[12]

The shortage of oxygen might well have prevented the rise of large, complex animals. The amount of oxygen an animal can absorb is largely determined by the area of its oxygen-absorbing surfaces (lungs and gills in the most complex animals; the skin in less complex ones); but, the amount needed is determined by its volume, which grows faster than the oxygen-absorbing area if an animal’s size increases equally in all directions. An increase in the concentration of oxygen in air or water would increase the size to which an organism could grow without its tissues becoming starved of oxygen. However, members of the Ediacara biota reached metres in length tens of millions of years before the Cambrian explosion.[33] Other metabolic functions may have been inhibited by lack of oxygen, for example the construction of tissue such as collagen, required for the construction of complex structures,[104] or to form molecules for the construction of a hard exoskeleton.[105] However, animals are not affected when similar oceanographic conditions occur in the Phanerozoic; there is no convincing correlation between oxygen levels and evolution, so oxygen may have been no more a prerequisite to complex life than liquid water or primary productivity.[106]
Snowball Earth
Main article: Snowball Earth

In the late Neoproterozoic (extending into the early Ediacaran period), the Earth suffered massive glaciations in which most of its surface was covered by ice. This may have caused a mass extinction, creating a genetic bottleneck; the resulting diversification may have given rise to the Ediacara biota, which appears soon after the last "Snowball Earth" episode.[107] However, the snowball episodes occurred a long time before the start of the Cambrian, and it is hard to see how so much diversity could have been caused by even a series of bottlenecks;[21] the cold periods may even have delayed the evolution of large size organisms.[44]
Increase in the calcium concentration of the Cambrian seawater

Newer research suggests that volcanically active midocean ridges caused a massive and sudden surge of the calcium concentration in the oceans, making it possible for marine organisms to build skeletons and hard body parts.[108] Alternatively a high influx of ions could have been provided by the widespread erosion that produced Powell's Great Unconformity.[109]
Developmental explanations

A range of theories are based on the concept that minor modifications to animals' development as they grow from embryo to adult may have been able to cause very large changes in the final adult form. The Hox genes, for example, control which organs individual regions of an embryo will develop into. For instance, if a certain Hox gene is expressed, a region will develop into a limb; if a different Hox gene is expressed in that region (a minor change), it could develop into an eye instead (a phenotypically major change).

Such a system allows a large range of disparity to appear from a limited set of genes, but such theories linking this with the explosion struggle to explain why the origin of such a development system should by itself lead to increased diversity or disparity. Evidence of Precambrian metazoans[21] combines with molecular data[110] to show that much of the genetic architecture that could feasibly have played a role in the explosion was already well established by the Cambrian.

This apparent paradox is addressed in a theory that focuses on the physics of development. It is proposed that the emergence of simple multicellular forms provided a changed context and spatial scale in which novel physical processes and effects were mobilized by the products of genes that had previously evolved to serve unicellular functions. Morphological complexity (layers, segments, lumens, appendages) arose, in this view, by self-organization.[111]
Ecological explanations

These focus on the interactions between different types of organism. Some of these hypotheses deal with changes in the food chain; some suggest arms races between predators and prey, and others focus on the more general mechanisms of coevolution. Such theories are well suited to explaining why there was a rapid increase in both disparity and diversity, but they must explain why the "explosion" happened when it did.[21]
End-Ediacaran mass extinction
Main article: End-Ediacaran extinction

Evidence for such an extinction includes the disappearance from the fossil record of the Ediacara biota and shelly fossils such as Cloudina, and the accompanying perturbation in the δ13C record.

Mass extinctions are often followed by adaptive radiations as existing clades expand to occupy the ecospace emptied by the extinction. However, once the dust had settled, overall disparity and diversity returned to the pre-extinction level in each of the Phanerozoic extinctions.[21]
Evolution of eyes
Main article: Evolution of the eye

Andrew Parker has proposed that predator-prey relationships changed dramatically after eyesight evolved. Prior to that time, hunting and evading were both close-range affairs – smell, vibration, and touch were the only senses used. When predators could see their prey from a distance, new defensive strategies were needed. Armor, spines, and similar defenses may also have evolved in response to vision. He further observed that, where animals lose vision in unlighted environments such as caves, diversity of animal forms tends to decrease.[112] Nevertheless, many scientists doubt that vision could have caused the explosion. Eyes may well have evolved long before the start of the Cambrian.[113] It is also difficult to understand why the evolution of eyesight would have caused an explosion, since other senses, such as smell and pressure detection, can detect things at a greater distance in the sea than sight can; but the appearance of these other senses apparently did not cause an evolutionary explosion.[21]
Arms races between predators and prey

The ability to avoid or recover from predation often makes the difference between life and death, and is therefore one of the strongest components of natural selection. The pressure to adapt is stronger on the prey than on the predator: if the predator fails to win a contest, it loses a meal; if the prey is the loser, it loses its life.[114]

But, there is evidence that predation was rife long before the start of the Cambrian, for example in the increasingly spiny forms of acritarchs, the holes drilled in Cloudina shells, and traces of burrowing to avoid predators. Hence, it is unlikely that the appearance of predation was the trigger for the Cambrian "explosion", although it may well have exhibited a strong influence on the body forms that the "explosion" produced.[44] However, the intensity of predation does appear to have increased dramatically during the Cambrian[115] as new predatory "tactics" (such as shell-crushing) emerged.[116]
Increase in size and diversity of planktonic animals

Geochemical evidence strongly indicates that the total mass of plankton has been similar to modern levels since early in the Proterozoic. Before the start of the Cambrian, their corpses and droppings were too small to fall quickly towards the seabed, since their drag was about the same as their weight. This meant they were destroyed by scavengers or by chemical processes before they reached the sea floor.[28]

Mesozooplankton are plankton of a larger size. Early Cambrian specimens filtered microscopic plankton from the seawater. These larger organisms would have produced droppings and corpses that were large enough to fall fairly quickly. This provided a new supply of energy and nutrients to the mid-levels and bottoms of the seas, which opened up a huge range of new possible ways of life. If any of these remains sank uneaten to the sea floor they could be buried; this would have taken some carbon out of circulation, resulting in an increase in the concentration of breathable oxygen in the seas (carbon readily combines with oxygen).[28]

The initial herbivorous mesozooplankton were probably larvae of benthic (seafloor) animals. A larval stage was probably an evolutionary innovation driven by the increasing level of predation at the seafloor during the Ediacaran period.[3][117]

Metazoans have an amazing ability to increase diversity through coevolution.[4] This means that an organism's traits can lead to traits evolving in other organisms; a number of responses are possible, and a different species can potentially emerge from each one. As a simple example, the evolution of predation may have caused one organism to develop a defence, while another developed motion to flee. This would cause the predator lineage to split into two species: one that was good at chasing prey, and another that was good at breaking through defences. Actual coevolution is somewhat more subtle, but, in this fashion, great diversity can arise: three quarters of living species are animals, and most of the rest have formed by coevolution with animals.[4]
Ecosystem engineering

Evolving organisms inevitably change the environment they evolve in. The Devonian colonization of land had planet-wide consequences for sediment cycling and ocean nutrients, and was likely linked to the Devonian mass extinction. A similar process may have occurred on smaller scales in the oceans, with, for example, the sponges filtering particles from the water and depositing them in the mud in a more digestible form; or burrowing organisms making previously unavailable resources available for other organisms.[118]

"Andrew Parker has proposed that predator-prey relationships changed dramatically after eyesight evolved...."

BTW...I read Andrew Parker's book, "The Genesis Enigma."

Did you?

 

[PoliticalChic]

There is no doubt that Darwin's theory is elegant, but if one wishes to move beyond philosophy, into empirical science, i.e., ideas backed up by actual physical evidence, Darwinism falls short. Here is the source of the problem:
'Before about 580 million years ago, most organisms were simple, composed of individual cells occasionally organized into colonies.... The Cambrian explosion, or Cambrian radiation, was the relatively rapid appearance, around 542 million years ago, of most major animal phyla, as demonstrated in the fossil record."
Cambrian explosion - Wikipedia, the free encyclopedia

Seems impossible for Darwinists to explain the appearences without a fossil trail leading to advanced creatures such as mentioned in the OP....and trilobites among others.

But even more amazing.....not just invertebrates!


Check this:

How about the sudden.....sudden....appearance of vertebrates in the Cambrian??

In 1999, paleontologists in Southern China also found fossil remains of fish in the Cambrian period.
Fish are vertebrates, members of the phylum chordata.
Shu, et. al., "Lower Cambrian Vertebrates in Southern China" (Haikouichthy) Evidence for a single median fin-fold and tail in the Lower Cambrian vertebrate, Haikouichthys ercaicunensis - Zhang - 2004 - Journal of Evolutionary Biology - Wiley Online Library



Whose theory does this sudden appearance seem to substantiate?
Certainly not Darwin's.

 

[Hollie]

"All kinds of things Charles Darwin did not understand in 1859 were figured out in the subsequent 150 years."


Could you provide a few of the explanations for Darwin's lacunae that are clear today?

Can you answer the query of the OP:
How, then, does this fit with Darwin's theory of gradual change which would be indicated by innumerable false starts and biological dead ends, indicating failures of random alterations?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.



In truth, you cannot answer the question, nor can contemporary evolutionary theory.


Another question?
Why do you make stuff up when it is so very easy to show you are no more than a source of hot air?

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.

Possible causes of the “explosion”

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.
Changes in the environment
Ozone formation

The amount of ozone required to shield Earth from biologically lethal UV radiation, wavelengths from 200 to 300 nanometers (nm), is believed to have been in existence around the Cambrian Explosion. The presence of the ozone formation enables the development of complex life and live on land, as opposed to life being restricted in the water.
Increase in oxygen levels

Earth’s earliest atmosphere contained no free oxygen; the oxygen that animals breathe today, both in the air and dissolved in water, is the product of billions of years of photosynthesis. As a general trend, the concentration of oxygen in the atmosphere has risen gradually over about the last 2.5 billion years.[12]

The shortage of oxygen might well have prevented the rise of large, complex animals. The amount of oxygen an animal can absorb is largely determined by the area of its oxygen-absorbing surfaces (lungs and gills in the most complex animals; the skin in less complex ones); but, the amount needed is determined by its volume, which grows faster than the oxygen-absorbing area if an animal’s size increases equally in all directions. An increase in the concentration of oxygen in air or water would increase the size to which an organism could grow without its tissues becoming starved of oxygen. However, members of the Ediacara biota reached metres in length tens of millions of years before the Cambrian explosion.[33] Other metabolic functions may have been inhibited by lack of oxygen, for example the construction of tissue such as collagen, required for the construction of complex structures,[104] or to form molecules for the construction of a hard exoskeleton.[105] However, animals are not affected when similar oceanographic conditions occur in the Phanerozoic; there is no convincing correlation between oxygen levels and evolution, so oxygen may have been no more a prerequisite to complex life than liquid water or primary productivity.[106]
Snowball Earth
Main article: Snowball Earth

In the late Neoproterozoic (extending into the early Ediacaran period), the Earth suffered massive glaciations in which most of its surface was covered by ice. This may have caused a mass extinction, creating a genetic bottleneck; the resulting diversification may have given rise to the Ediacara biota, which appears soon after the last "Snowball Earth" episode.[107] However, the snowball episodes occurred a long time before the start of the Cambrian, and it is hard to see how so much diversity could have been caused by even a series of bottlenecks;[21] the cold periods may even have delayed the evolution of large size organisms.[44]
Increase in the calcium concentration of the Cambrian seawater

Newer research suggests that volcanically active midocean ridges caused a massive and sudden surge of the calcium concentration in the oceans, making it possible for marine organisms to build skeletons and hard body parts.[108] Alternatively a high influx of ions could have been provided by the widespread erosion that produced Powell's Great Unconformity.[109]
Developmental explanations

A range of theories are based on the concept that minor modifications to animals' development as they grow from embryo to adult may have been able to cause very large changes in the final adult form. The Hox genes, for example, control which organs individual regions of an embryo will develop into. For instance, if a certain Hox gene is expressed, a region will develop into a limb; if a different Hox gene is expressed in that region (a minor change), it could develop into an eye instead (a phenotypically major change).

Such a system allows a large range of disparity to appear from a limited set of genes, but such theories linking this with the explosion struggle to explain why the origin of such a development system should by itself lead to increased diversity or disparity. Evidence of Precambrian metazoans[21] combines with molecular data[110] to show that much of the genetic architecture that could feasibly have played a role in the explosion was already well established by the Cambrian.

This apparent paradox is addressed in a theory that focuses on the physics of development. It is proposed that the emergence of simple multicellular forms provided a changed context and spatial scale in which novel physical processes and effects were mobilized by the products of genes that had previously evolved to serve unicellular functions. Morphological complexity (layers, segments, lumens, appendages) arose, in this view, by self-organization.[111]
Ecological explanations

These focus on the interactions between different types of organism. Some of these hypotheses deal with changes in the food chain; some suggest arms races between predators and prey, and others focus on the more general mechanisms of coevolution. Such theories are well suited to explaining why there was a rapid increase in both disparity and diversity, but they must explain why the "explosion" happened when it did.[21]
End-Ediacaran mass extinction
Main article: End-Ediacaran extinction

Evidence for such an extinction includes the disappearance from the fossil record of the Ediacara biota and shelly fossils such as Cloudina, and the accompanying perturbation in the δ13C record.

Mass extinctions are often followed by adaptive radiations as existing clades expand to occupy the ecospace emptied by the extinction. However, once the dust had settled, overall disparity and diversity returned to the pre-extinction level in each of the Phanerozoic extinctions.[21]
Evolution of eyes
Main article: Evolution of the eye

Andrew Parker has proposed that predator-prey relationships changed dramatically after eyesight evolved. Prior to that time, hunting and evading were both close-range affairs – smell, vibration, and touch were the only senses used. When predators could see their prey from a distance, new defensive strategies were needed. Armor, spines, and similar defenses may also have evolved in response to vision. He further observed that, where animals lose vision in unlighted environments such as caves, diversity of animal forms tends to decrease.[112] Nevertheless, many scientists doubt that vision could have caused the explosion. Eyes may well have evolved long before the start of the Cambrian.[113] It is also difficult to understand why the evolution of eyesight would have caused an explosion, since other senses, such as smell and pressure detection, can detect things at a greater distance in the sea than sight can; but the appearance of these other senses apparently did not cause an evolutionary explosion.[21]
Arms races between predators and prey

The ability to avoid or recover from predation often makes the difference between life and death, and is therefore one of the strongest components of natural selection. The pressure to adapt is stronger on the prey than on the predator: if the predator fails to win a contest, it loses a meal; if the prey is the loser, it loses its life.[114]

But, there is evidence that predation was rife long before the start of the Cambrian, for example in the increasingly spiny forms of acritarchs, the holes drilled in Cloudina shells, and traces of burrowing to avoid predators. Hence, it is unlikely that the appearance of predation was the trigger for the Cambrian "explosion", although it may well have exhibited a strong influence on the body forms that the "explosion" produced.[44] However, the intensity of predation does appear to have increased dramatically during the Cambrian[115] as new predatory "tactics" (such as shell-crushing) emerged.[116]
Increase in size and diversity of planktonic animals

Geochemical evidence strongly indicates that the total mass of plankton has been similar to modern levels since early in the Proterozoic. Before the start of the Cambrian, their corpses and droppings were too small to fall quickly towards the seabed, since their drag was about the same as their weight. This meant they were destroyed by scavengers or by chemical processes before they reached the sea floor.[28]

Mesozooplankton are plankton of a larger size. Early Cambrian specimens filtered microscopic plankton from the seawater. These larger organisms would have produced droppings and corpses that were large enough to fall fairly quickly. This provided a new supply of energy and nutrients to the mid-levels and bottoms of the seas, which opened up a huge range of new possible ways of life. If any of these remains sank uneaten to the sea floor they could be buried; this would have taken some carbon out of circulation, resulting in an increase in the concentration of breathable oxygen in the seas (carbon readily combines with oxygen).[28]

The initial herbivorous mesozooplankton were probably larvae of benthic (seafloor) animals. A larval stage was probably an evolutionary innovation driven by the increasing level of predation at the seafloor during the Ediacaran period.[3][117]

Metazoans have an amazing ability to increase diversity through coevolution.[4] This means that an organism's traits can lead to traits evolving in other organisms; a number of responses are possible, and a different species can potentially emerge from each one. As a simple example, the evolution of predation may have caused one organism to develop a defence, while another developed motion to flee. This would cause the predator lineage to split into two species: one that was good at chasing prey, and another that was good at breaking through defences. Actual coevolution is somewhat more subtle, but, in this fashion, great diversity can arise: three quarters of living species are animals, and most of the rest have formed by coevolution with animals.[4]
Ecosystem engineering

Evolving organisms inevitably change the environment they evolve in. The Devonian colonization of land had planet-wide consequences for sediment cycling and ocean nutrients, and was likely linked to the Devonian mass extinction. A similar process may have occurred on smaller scales in the oceans, with, for example, the sponges filtering particles from the water and depositing them in the mud in a more digestible form; or burrowing organisms making previously unavailable resources available for other organisms.[118]

Much better!

An actual attempt to respond.

Unfortunately, it doesn't respond to the question posed by the OP.
Possibly you had some other OP in mind...this one: "how to explain the sudden rise of such extensive diversity during the Cambrian?"


My question was, why are there no fossil trails culminating in the new organisms found in the Cambrian?


Get it?

Not, why did new organisms result....but where is the proof that they were the result of a series of changes?



Again:

a. Steven J. Gould reported: "In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and fully formed." (Natural History, 86:12-16)

b. "And let us dispose of a common misconception. The complete transmutation of even one animal species into a different species has never been directly observed either in the laboratory or in the field."
Dean H. Kenyon (Professor of Biology, San Francisco State University), affidavit presented to the U.S. Supreme Court, No. 85-1513, Brief of Appellants, prepared under the direction of William J. Guste, Jr., Attorney General of the State of Louisiana, October 1985, p. A-16.



Do you see the problem?
There is no evidence of one species becoming another....and this is the basis of evolution.



Care to take another shot?

Why are you still posting phony "quotes" when you have been exposed repeatedly as a fraud?

Have you forgotten that your Steven J. Gould "quote" (as well as the Dean Kenyon "quote") are frauds that you stole from Harun Yahya?

Once again, here is the Steven J. Gould "quote" that Harun Yahya (and you), fraudulently cut up.

Quote Mine Project: "Sudden Appearance and Stasis"

Your phony "quotes" have long ago been exposed as frauds but continue to appear at the hands of Harun Yahya groupies and religious whack-jobs.

 

[Old Rocks]

Creationism is not a science that has been proven either.

This OP was not about Creationism......simply provided proof that Darwinian evolution is not scientific, in that it has on proof, is not testable, and has data as in the OP that runs counter to it.

Assuming that you are articulate, and write what you mean...."Creationism is not a science that has been proven either."....

...the "either" refers to Darwin's theory.

In which case, I agree.

LOL.

The Ediacaran Period

Strange you should quote out of context from Stephen Jay Gould's writing. Not strange at all that you should misinterpret the arguement he makes for punctated evolution. But expecting you to actually read enough concerning evolutionary biology to discuss it intelligently would be expecting far too much.

So, Sis, let me tell you a little secret. Scientists don't investigate to find evidence to fit their favorite theories, they find evidence and then create theories. You are engaged in exactly to opposite. You are a Creationist, and as such, simply cannot except the overwhelming evidence that Darwin was correct in most of his theory.

Today, the Theory of Evolution stands as the most robust of all scientific theories. We have observed speciation, we understand much of how the genetics of evolution work, and we are actually engineering organisms using this understanding.

You wish to remain in the 18th century, be my guest. Don't expect reasonably intelligent and sane individuals to wish to join you.

 

[PainefulTruth]

Let's be clear.

I believe in science.

Science is based on evidence. Here's what science was:
"Empiricism in the philosophy of science emphasizes evidence, especially as discovered in experiments. It is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world rather than resting solely on a priori reasoning, intuition, or revelation.."
Empiricism - Wikipedia, the free encyclopedia

Darwin's theory is elegant. The logic, even without physical evidence, is unassailable.
But it is not science...it is conjecture and consensus.

....there are now two versions of science.
Rationalists claim that there are significant ways in which our concepts and knowledge are gained independently of sense experience. Empiricists claim that sense experience is the ultimate source of all our concepts and knowledge.
Rationalism vs. Empiricism (Stanford Encyclopedia of Philosophy)


My point: if Darwin is science that you will accept, then all the other philosophical discussions of how organisms arose must also be accepted.
All of them are based on faith....as is Darwin's theory of evolution.

The argument is not about how life arose on Earth, that's a totally different area open for investigation. As you labeled it yourself, it's "Darwin's theory of evolution", not bio-genesis. And the scientific method varies according to the field of inquiry. Lab experiments are not always necessary. It is impossible to measure all hydrogen atoms to show they all have only one proton with the same atomic weight, and other measurable characteristics of hydrogen (including isotopes).

That's what you would have us do, dismiss the chain of evidence of evolution because it doesn't show every step for all species past and present. Experiments don't all occur in a lab. Geology, paleontology and archaeology all depend on repeatably testable evidence from the stratigraphic record compiled from examinations around the world, and sometimes off of it.

 

[orogenicman]

To further skewer the evolutionary biologists, one need simply note exactly how definitive are the first appearances of many marine invertebrate animals!

"Some of these animals have mineralized exoskeletons, including those representing phyla, such as echinoderms, brachiopods, and arthropods, and each represent clearly distinct and novel body plans."
Meyers, "Darwin's Doubt," p. 34.


Any with an open mind, a scientific outlook, would have to agree that such brand-new developments flies in the face of any Darwinian-type view: no gradualism, no series of changes.....

...just new organisms.


How could this be?

Religious zealots typically cut and paste from hacks such as Meyer. As a shill for the Disco'tute, his agenda is to appeal to Ignorance on the part of those who need to vilify science.

Still not equipped to answer the questions.....

....so, your usual 'is not, is not' post.


OK....you can go now.

I have a question for you, PC. Did you ever find that Cambrian bunny rabbit?

 

[Two Thumbs]

I watched a special on darwin, one of the things he found was a flower whose nectar was 10" inside a narrow flower. so he surmised that there must be a life form with a 10" tongue/beak that could reach it. Low and behold, decades later they found a moth with a 10" tongue.

This proved darwin to them.

To me, it proved darwin wrong.

A flower cannot survive unless it gets pollinated, nothing will come if it can't eat, therefore they moth was there with it's 10" tongue at the same time as the flower.
and of course, the moth w/o the flower, wouldn't need a 10" tongue.


cracks me up to hear scientist trying to prove Einstein wrong but darwin is like arguing against god himself.

 

[PoliticalChic]

The import of the Burgess Shale: how to explain the sudden rise of such extensive diversity during the Cambrian?
Note how this question is ignored by the most ardent of fanatics. And why it is ignored.
Ignoring evidence to the contrary is hardly science.
In fact, it is the very antithesis of science.

Possible causes of the “explosion”

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.
Changes in the environment
Ozone formation

The amount of ozone required to shield Earth from biologically lethal UV radiation, wavelengths from 200 to 300 nanometers (nm), is believed to have been in existence around the Cambrian Explosion. The presence of the ozone formation enables the development of complex life and live on land, as opposed to life being restricted in the water.
Increase in oxygen levels

Earth’s earliest atmosphere contained no free oxygen; the oxygen that animals breathe today, both in the air and dissolved in water, is the product of billions of years of photosynthesis. As a general trend, the concentration of oxygen in the atmosphere has risen gradually over about the last 2.5 billion years.[12]

The shortage of oxygen might well have prevented the rise of large, complex animals. The amount of oxygen an animal can absorb is largely determined by the area of its oxygen-absorbing surfaces (lungs and gills in the most complex animals; the skin in less complex ones); but, the amount needed is determined by its volume, which grows faster than the oxygen-absorbing area if an animal’s size increases equally in all directions. An increase in the concentration of oxygen in air or water would increase the size to which an organism could grow without its tissues becoming starved of oxygen. However, members of the Ediacara biota reached metres in length tens of millions of years before the Cambrian explosion.[33] Other metabolic functions may have been inhibited by lack of oxygen, for example the construction of tissue such as collagen, required for the construction of complex structures,[104] or to form molecules for the construction of a hard exoskeleton.[105] However, animals are not affected when similar oceanographic conditions occur in the Phanerozoic; there is no convincing correlation between oxygen levels and evolution, so oxygen may have been no more a prerequisite to complex life than liquid water or primary productivity.[106]
Snowball Earth
Main article: Snowball Earth

In the late Neoproterozoic (extending into the early Ediacaran period), the Earth suffered massive glaciations in which most of its surface was covered by ice. This may have caused a mass extinction, creating a genetic bottleneck; the resulting diversification may have given rise to the Ediacara biota, which appears soon after the last "Snowball Earth" episode.[107] However, the snowball episodes occurred a long time before the start of the Cambrian, and it is hard to see how so much diversity could have been caused by even a series of bottlenecks;[21] the cold periods may even have delayed the evolution of large size organisms.[44]
Increase in the calcium concentration of the Cambrian seawater

Newer research suggests that volcanically active midocean ridges caused a massive and sudden surge of the calcium concentration in the oceans, making it possible for marine organisms to build skeletons and hard body parts.[108] Alternatively a high influx of ions could have been provided by the widespread erosion that produced Powell's Great Unconformity.[109]
Developmental explanations

A range of theories are based on the concept that minor modifications to animals' development as they grow from embryo to adult may have been able to cause very large changes in the final adult form. The Hox genes, for example, control which organs individual regions of an embryo will develop into. For instance, if a certain Hox gene is expressed, a region will develop into a limb; if a different Hox gene is expressed in that region (a minor change), it could develop into an eye instead (a phenotypically major change).

Such a system allows a large range of disparity to appear from a limited set of genes, but such theories linking this with the explosion struggle to explain why the origin of such a development system should by itself lead to increased diversity or disparity. Evidence of Precambrian metazoans[21] combines with molecular data[110] to show that much of the genetic architecture that could feasibly have played a role in the explosion was already well established by the Cambrian.

This apparent paradox is addressed in a theory that focuses on the physics of development. It is proposed that the emergence of simple multicellular forms provided a changed context and spatial scale in which novel physical processes and effects were mobilized by the products of genes that had previously evolved to serve unicellular functions. Morphological complexity (layers, segments, lumens, appendages) arose, in this view, by self-organization.[111]
Ecological explanations

These focus on the interactions between different types of organism. Some of these hypotheses deal with changes in the food chain; some suggest arms races between predators and prey, and others focus on the more general mechanisms of coevolution. Such theories are well suited to explaining why there was a rapid increase in both disparity and diversity, but they must explain why the "explosion" happened when it did.[21]
End-Ediacaran mass extinction
Main article: End-Ediacaran extinction

Evidence for such an extinction includes the disappearance from the fossil record of the Ediacara biota and shelly fossils such as Cloudina, and the accompanying perturbation in the δ13C record.

Mass extinctions are often followed by adaptive radiations as existing clades expand to occupy the ecospace emptied by the extinction. However, once the dust had settled, overall disparity and diversity returned to the pre-extinction level in each of the Phanerozoic extinctions.[21]
Evolution of eyes
Main article: Evolution of the eye

Andrew Parker has proposed that predator-prey relationships changed dramatically after eyesight evolved. Prior to that time, hunting and evading were both close-range affairs – smell, vibration, and touch were the only senses used. When predators could see their prey from a distance, new defensive strategies were needed. Armor, spines, and similar defenses may also have evolved in response to vision. He further observed that, where animals lose vision in unlighted environments such as caves, diversity of animal forms tends to decrease.[112] Nevertheless, many scientists doubt that vision could have caused the explosion. Eyes may well have evolved long before the start of the Cambrian.[113] It is also difficult to understand why the evolution of eyesight would have caused an explosion, since other senses, such as smell and pressure detection, can detect things at a greater distance in the sea than sight can; but the appearance of these other senses apparently did not cause an evolutionary explosion.[21]
Arms races between predators and prey

The ability to avoid or recover from predation often makes the difference between life and death, and is therefore one of the strongest components of natural selection. The pressure to adapt is stronger on the prey than on the predator: if the predator fails to win a contest, it loses a meal; if the prey is the loser, it loses its life.[114]

But, there is evidence that predation was rife long before the start of the Cambrian, for example in the increasingly spiny forms of acritarchs, the holes drilled in Cloudina shells, and traces of burrowing to avoid predators. Hence, it is unlikely that the appearance of predation was the trigger for the Cambrian "explosion", although it may well have exhibited a strong influence on the body forms that the "explosion" produced.[44] However, the intensity of predation does appear to have increased dramatically during the Cambrian[115] as new predatory "tactics" (such as shell-crushing) emerged.[116]
Increase in size and diversity of planktonic animals

Geochemical evidence strongly indicates that the total mass of plankton has been similar to modern levels since early in the Proterozoic. Before the start of the Cambrian, their corpses and droppings were too small to fall quickly towards the seabed, since their drag was about the same as their weight. This meant they were destroyed by scavengers or by chemical processes before they reached the sea floor.[28]

Mesozooplankton are plankton of a larger size. Early Cambrian specimens filtered microscopic plankton from the seawater. These larger organisms would have produced droppings and corpses that were large enough to fall fairly quickly. This provided a new supply of energy and nutrients to the mid-levels and bottoms of the seas, which opened up a huge range of new possible ways of life. If any of these remains sank uneaten to the sea floor they could be buried; this would have taken some carbon out of circulation, resulting in an increase in the concentration of breathable oxygen in the seas (carbon readily combines with oxygen).[28]

The initial herbivorous mesozooplankton were probably larvae of benthic (seafloor) animals. A larval stage was probably an evolutionary innovation driven by the increasing level of predation at the seafloor during the Ediacaran period.[3][117]

Metazoans have an amazing ability to increase diversity through coevolution.[4] This means that an organism's traits can lead to traits evolving in other organisms; a number of responses are possible, and a different species can potentially emerge from each one. As a simple example, the evolution of predation may have caused one organism to develop a defence, while another developed motion to flee. This would cause the predator lineage to split into two species: one that was good at chasing prey, and another that was good at breaking through defences. Actual coevolution is somewhat more subtle, but, in this fashion, great diversity can arise: three quarters of living species are animals, and most of the rest have formed by coevolution with animals.[4]
Ecosystem engineering

Evolving organisms inevitably change the environment they evolve in. The Devonian colonization of land had planet-wide consequences for sediment cycling and ocean nutrients, and was likely linked to the Devonian mass extinction. A similar process may have occurred on smaller scales in the oceans, with, for example, the sponges filtering particles from the water and depositing them in the mud in a more digestible form; or burrowing organisms making previously unavailable resources available for other organisms.[118]

Much better!

An actual attempt to respond.

Unfortunately, it doesn't respond to the question posed by the OP.
Possibly you had some other OP in mind...this one: "how to explain the sudden rise of such extensive diversity during the Cambrian?"


My question was, why are there no fossil trails culminating in the new organisms found in the Cambrian?


Get it?

Not, why did new organisms result....but where is the proof that they were the result of a series of changes?



Again:

a. Steven J. Gould reported: "In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and fully formed." (Natural History, 86:12-16)

b. "And let us dispose of a common misconception. The complete transmutation of even one animal species into a different species has never been directly observed either in the laboratory or in the field."
Dean H. Kenyon (Professor of Biology, San Francisco State University), affidavit presented to the U.S. Supreme Court, No. 85-1513, Brief of Appellants, prepared under the direction of William J. Guste, Jr., Attorney General of the State of Louisiana, October 1985, p. A-16.



Do you see the problem?
There is no evidence of one species becoming another....and this is the basis of evolution.



Care to take another shot?

Why are you still posting phony "quotes" when you have been exposed repeatedly as a fraud?

Have you forgotten that your Steven J. Gould "quote" (as well as the Dean Kenyon "quote") are frauds that you stole from Harun Yahya?

Once again, here is the Steven J. Gould "quote" that Harun Yahya (and you), fraudulently cut up.

Quote Mine Project: "Sudden Appearance and Stasis"

Your phony "quotes" have long ago been exposed as frauds but continue to appear at the hands of Harun Yahya groupies and religious whack-jobs.

Every quote that I provide is accurate and correct.

Don't be afraid of the truth.

 

[PoliticalChic]

Creationism is not a science that has been proven either.

This OP was not about Creationism......simply provided proof that Darwinian evolution is not scientific, in that it has on proof, is not testable, and has data as in the OP that runs counter to it.

Assuming that you are articulate, and write what you mean...."Creationism is not a science that has been proven either."....

...the "either" refers to Darwin's theory.

In which case, I agree.

LOL.

The Ediacaran Period

Strange you should quote out of context from Stephen Jay Gould's writing. Not strange at all that you should misinterpret the arguement he makes for punctated evolution. But expecting you to actually read enough concerning evolutionary biology to discuss it intelligently would be expecting far too much.

So, Sis, let me tell you a little secret. Scientists don't investigate to find evidence to fit their favorite theories, they find evidence and then create theories. You are engaged in exactly to opposite. You are a Creationist, and as such, simply cannot except the overwhelming evidence that Darwin was correct in most of his theory.

Today, the Theory of Evolution stands as the most robust of all scientific theories. We have observed speciation, we understand much of how the genetics of evolution work, and we are actually engineering organisms using this understanding.

You wish to remain in the 18th century, be my guest. Don't expect reasonably intelligent and sane individuals to wish to join you.

"punctated evolution" is, in fact a repudiation of Darwin's theory.

It was designed to suck in the dolts who still endorse Darwin....raise your paw....and yet give another name to the proof that I provided in the OP.


You see, "punctated evolution" simply means that organisms appear fully formed, and we cannot find antecedents for them.


As I show in the OP.



Rocks....the dumbest among us simply accept a new terminology without considering what it means.




"Strange you should quote out of context from Stephen Jay Gould's writing."

Really?

Did he, or did he not, state:

Steven J. Gould reported: "In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and fully formed." (Natural History, 86:12-16)

Need a larger portion, saying the same thing from Gould? Sure:
a. "Stasis. Most species exhibit no directional change during their tenure on earth. They appear in the fossil record looking much the same as when they disappear; morphological change is usually limited and directionless. 2. Sudden appearance. In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and ‘fully formed.’”
(Gould, Stephen J. The Panda’s Thumb, 1980, p. 181-182.).'" (Gould, Stephen J. The Panda's Thumb, 1980, p. 181-182)

If that is not correct....please show how he really meant the opposite.

And....in that quote....is he not verifying the OP?




Just between us, Rocks....do you foresee the day when you realize that you are stupid?

 

[orogenicman]

Much better!

An actual attempt to respond.

Unfortunately, it doesn't respond to the question posed by the OP.
Possibly you had some other OP in mind...this one: "how to explain the sudden rise of such extensive diversity during the Cambrian?"


My question was, why are there no fossil trails culminating in the new organisms found in the Cambrian?


Get it?

Not, why did new organisms result....but where is the proof that they were the result of a series of changes?



Again:

a. Steven J. Gould reported: "In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and fully formed." (Natural History, 86:12-16)

b. "And let us dispose of a common misconception. The complete transmutation of even one animal species into a different species has never been directly observed either in the laboratory or in the field."
Dean H. Kenyon (Professor of Biology, San Francisco State University), affidavit presented to the U.S. Supreme Court, No. 85-1513, Brief of Appellants, prepared under the direction of William J. Guste, Jr., Attorney General of the State of Louisiana, October 1985, p. A-16.



Do you see the problem?
There is no evidence of one species becoming another....and this is the basis of evolution.



Care to take another shot?

Why are you still posting phony "quotes" when you have been exposed repeatedly as a fraud?

Have you forgotten that your Steven J. Gould "quote" (as well as the Dean Kenyon "quote") are frauds that you stole from Harun Yahya?

Once again, here is the Steven J. Gould "quote" that Harun Yahya (and you), fraudulently cut up.

Quote Mine Project: "Sudden Appearance and Stasis"

Your phony "quotes" have long ago been exposed as frauds but continue to appear at the hands of Harun Yahya groupies and religious whack-jobs.

Every quote that I provide is accurate and correct.

Don't be afraid of the truth.

Every one of those quotes have been shown time and time again to be taken out of context, and every one of the authors you are misquoting would tell you that they subscribe to the theory of evolution and that you are a dishonest fool.

 

[PoliticalChic]

Creationism is not a science that has been proven either.

This OP was not about Creationism......simply provided proof that Darwinian evolution is not scientific, in that it has on proof, is not testable, and has data as in the OP that runs counter to it.

Assuming that you are articulate, and write what you mean...."Creationism is not a science that has been proven either."....

...the "either" refers to Darwin's theory.

In which case, I agree.

LOL.

The Ediacaran Period

Strange you should quote out of context from Stephen Jay Gould's writing. Not strange at all that you should misinterpret the arguement he makes for punctated evolution. But expecting you to actually read enough concerning evolutionary biology to discuss it intelligently would be expecting far too much.

So, Sis, let me tell you a little secret. Scientists don't investigate to find evidence to fit their favorite theories, they find evidence and then create theories. You are engaged in exactly to opposite. You are a Creationist, and as such, simply cannot except the overwhelming evidence that Darwin was correct in most of his theory.

Today, the Theory of Evolution stands as the most robust of all scientific theories. We have observed speciation, we understand much of how the genetics of evolution work, and we are actually engineering organisms using this understanding.

You wish to remain in the 18th century, be my guest. Don't expect reasonably intelligent and sane individuals to wish to join you.

" Scientists don't investigate to find evidence to fit their favorite theories,..."

Truly....you are blind to human nature.





Came across this in a book I read recently.....


In her police novel, "Judging Time," Leslie Glass makes the point that some officers latch onto an idea and ignore any facts to the contrary.

"...Hagedorn was beginning to seriously irritate her. He'd just get hold of an idea and push it around on his plate until he could find the right position for it, then he'd look for facts to back up his theory. She'd heard that scientists did that too, so you could never believe the conclusions of any scientific study. Sometimes April thought there was no one in the world who told the truth."

Pretty good summary of some scientist's use of "critical thinking."



You'd better be sitting down when I tell you this, Rocks:
Scientists are human being.
They cheat as much as any other humans, and, for basically the same reasons.

 

[PoliticalChic]

Let's be clear.

I believe in science.

Science is based on evidence. Here's what science was:
"Empiricism in the philosophy of science emphasizes evidence, especially as discovered in experiments. It is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world rather than resting solely on a priori reasoning, intuition, or revelation.."
Empiricism - Wikipedia, the free encyclopedia

Darwin's theory is elegant. The logic, even without physical evidence, is unassailable.
But it is not science...it is conjecture and consensus.

....there are now two versions of science.
Rationalists claim that there are significant ways in which our concepts and knowledge are gained independently of sense experience. Empiricists claim that sense experience is the ultimate source of all our concepts and knowledge.
Rationalism vs. Empiricism (Stanford Encyclopedia of Philosophy)


My point: if Darwin is science that you will accept, then all the other philosophical discussions of how organisms arose must also be accepted.
All of them are based on faith....as is Darwin's theory of evolution.

The argument is not about how life arose on Earth, that's a totally different area open for investigation. As you labeled it yourself, it's "Darwin's theory of evolution", not bio-genesis. And the scientific method varies according to the field of inquiry. Lab experiments are not always necessary. It is impossible to measure all hydrogen atoms to show they all have only one proton with the same atomic weight, and other measurable characteristics of hydrogen (including isotopes).

That's what you would have us do, dismiss the chain of evidence of evolution because it doesn't show every step for all species past and present. Experiments don't all occur in a lab. Geology, paleontology and archaeology all depend on repeatably testable evidence from the stratigraphic record compiled from examinations around the world, and sometimes off of it.

"And the scientific method varies according to the field of inquiry."

No it doesn't.



There is science...based on the scientific method.
Then there is some variety of philosophy attempting to piggy-back on the reputation of real science. The alternative is based on conjecture and consensus.
It survives because of the huge amount of funding provided by the Leftist ideology that requires it to.


The real irony is that the 'alternative form' is, fundamentally, based on faith.....and yet it attacks religion because it is based on faith rather than the scientific method.


Funny, in a pathetic kind of way.

 

[PoliticalChic]

Religious zealots typically cut and paste from hacks such as Meyer. As a shill for the Disco'tute, his agenda is to appeal to Ignorance on the part of those who need to vilify science.

Still not equipped to answer the questions.....

....so, your usual 'is not, is not' post.


OK....you can go now.

I have a question for you, PC. Did you ever find that Cambrian bunny rabbit?

Don't speak to me until you admit that you are a liar, and lying is your default.

 

[orogenicman]

Still not equipped to answer the questions.....

....so, your usual 'is not, is not' post.


OK....you can go now.

I have a question for you, PC. Did you ever find that Cambrian bunny rabbit?

Don't speak to me until you admit that you are a liar, and lying is your default.

I challenge you to find a single instance where I have lied. While you are at it, let us know if you ever found that Cambrian bunny rabbit.

 

[PoliticalChic]

Why are you still posting phony "quotes" when you have been exposed repeatedly as a fraud?

Have you forgotten that your Steven J. Gould "quote" (as well as the Dean Kenyon "quote") are frauds that you stole from Harun Yahya?

Once again, here is the Steven J. Gould "quote" that Harun Yahya (and you), fraudulently cut up.

Quote Mine Project: "Sudden Appearance and Stasis"

Your phony "quotes" have long ago been exposed as frauds but continue to appear at the hands of Harun Yahya groupies and religious whack-jobs.

Every quote that I provide is accurate and correct.

Don't be afraid of the truth.

Every one of those quotes have been shown time and time again to be taken out of context, and every one of the authors you are misquoting would tell you that they subscribe to the theory of evolution and that you are a dishonest fool.

Liar.

 

[orogenicman]

Every quote that I provide is accurate and correct.

Don't be afraid of the truth.

Every one of those quotes have been shown time and time again to be taken out of context, and every one of the authors you are misquoting would tell you that they subscribe to the theory of evolution and that you are a dishonest fool.

Liar.

Simply making a claim doesn't make it true. I could claim that you are an Islamic terrorist but without providing any evidence, my claim would have as much basis as yours. In other words, none at all. So, I challenge you to find a single instance where I have lied AND provide evidence to support your claim that I lied. While you are at it, let us know if you ever found that Cambrian bunny rabbit.