Origins Thread

[Myles O'Reilly]

Richard Dawkins demonstrates laryngeal nerve of the giraffe​

Oh dear. We're not back to the exploding Giraffe heads are we?

 

[Fishalt]

Oh dear. We're not back to the exploding Giraffe heads are we?

I'm not sure what you mean.

 

[Myles O'Reilly]

Were you not involved in the Giraffe debate earlier in this thread Sir?

 

[Fishalt]

Were you not involved in the Giraffe debate earlier in this thread Sir?

Possibly. I don't remember.

 

[Tiger]

Regardless, it's still poor design. Certainly not intelligent. No explanation for it other than the one given by Biologists holds any water.

So good of you to start contributing to this thread.


Walk us through, step by step the Darwinian evolution of the blood clotting system. Something which no living organism can survive without.

 

[Fishalt]

So good of you to start contributing to this thread.


Walk us through, step by step the Darwinian evolution of the blood clotting system. Something which no living organism can survive without.

Here you are.

The slow and steady march up the gradual incline is no picnic. Passage is governed by a series of unforgiving rules, or laws of nature. For one, every step must confer a survival or reproductive advantage. Second, the path is one-way; a species or trait cannot reverse course and get worse as a means towards eventual improvement. Finally, there are no sudden leaps or precipitous increases in ordered complexity.

Today, the coagulation mechanism metaphorically rests at the summit of the mountain. For those of us who studied the clotting cascade in medical school, we are fully aware of its awe-inspiring, not to mention intimidating, complexity. How remarkable, most of us would agree, that the mechanism arose through step-by-step modification and natural selection over the eons… what a marvel of evolutionary sculpting!

Creationists have a different take. My goodness, they claim, the clotting cascade is so complex that it could not possibly have arisen from small beginnings by a gradual series of incremental changes. Nope, they conclude, the clotting cascade is irreducibly complex. Like a mousetrap, the proper functioning of the coagulation mechanism is all or nothing: take away a single component and the whole system fails. The only route to the summit is by way of the cliff, and the only way up the cliff is on the shoulders of a divine creator.

Michael Behe, a Professor of Biochemistry at Lehigh University devoted an entire chapter in his book, Darwin’s Black Box, to the clotting cascade.2 In his book, he states that, “Blood coagulation is a paradigm of staggering complexity that underlies even apparently simple bodily processes. Faced with such complexity beneath even simple phenomena, Darwinian theory falls silent”. Behe went on to write: “The bottom line is that clusters for proteins have to be inserted all at once into the cascade. This can be done by postulating… the guidance of an intelligent agent.”

How do we even begin to address these assertions? We can ignore them, but that doesn’t help to mitigate the published misconceptions and deceptions, so readily accessible in the popular press. The Biological Sciences Department page on the Lehigh University website has a prominent disclaimer: “While we respect Prof. Behe’s right to express his views, they are his alone and are in no way endorsed by the department. It is our collective position that intelligent design has not basis in science”.3 Ouch.

Rather than censoring Behe, let’s take him on. Not because there is any merit to his position, but because, as noted by a famous biologist from the early 20th century, “nothing makes sense except in the light of evolution”.4 The first point to make is that irreducible complexity, which is defined as a system with several interacting parts that ceases to function when any one component is removed, is not evidence of divine creation. Biology is full of irreducible complexity – just think of the many single gene knockouts in mice that lead to embryonic lethality – but the interlocking nature of complex designs is as much a product of evolution as the single components themselves. Indeed, biological systems display non-linear dynamics and emergent properties such that the system cannot be understood by the studying the individual parts in isolation.

But does the coagulation system even meet the definition of irreducible complexity? The answer is no. The clotting cascade consists of sequential activation of a series of proenzymes or inactive precursor proteins (zymogens) to active enzymes. There are two arms to the clotting cascade: intrinsic and extrinsic. Both converge on the common pathway, which ultimately promotes thrombin generation and fibrin formation.

Humans who are deficient in one or another zymogen often have bleeding diatheses, but many can live a normal life and reproduce. Well, you might argue, these patients have some residual activity of their deficient factor, and perhaps that’s enough to keep them alive. However, genetically engineered mice who have complete loss of certain clotting factors, are also viable. Perhaps the most surprising is the mouse that lacks fibrinogen. They cannot make any fibrin plugs, yet they are viable, provided they are not subject to surgical procedures.5 The fact that a mammal can survive without any fibrinogen is the antithesis of irreducible complexity.

Second, despite the Creationists contention that the clotting cascade arose all at once, the evidence speaks otherwise. By examining the genomes of various classes of extant vertebrates, it is possible to infer the evolutionary history of the coagulation system. We learn that the clotting cascade first arose in an ancestral vertebrate some 600 million years ago. Moreover, the clotting cascade, as we recognize it in humans, did not evolve all at once. The extrinsic system appeared first (in jawless fish), followed by FIX (in jawed fish) and then the contact system (in amphibians) (see Figure below). This sequence of events is backed by strong biological plausibility: clotting is always initiated by the FVII of the extrinsic cascade, is amplified by FIX of the intrinsic pathway and is further accelerated by FXI, which lies downstream of the contact pathway.

The clotting cascade is absent in invertebrates and present (in one form or another) in all vertebrates. Therefore it evolved in the ancestral vertebrate some 600 million years ago, over a short time frame of 50-100 million years. The Creationists and their ilk have argued that the clotting cascade could not possibly have evolved over such a short period of time by step-by-step modification. This is what Dawkins refers to as the argument from personal incredulity: “Wow, so much to assemble in such a short period of time, there is no other explanation than Divine intervention!” Such intellectual laziness does little to further the discussion. Who is to say what is too short in evolutionary time? The fact that the clotting cascade arose quickly speaks to the power and versatility of gene duplications and exon shuffling and explains the high degree of homology between the various components of the clotting cascade.

Sadly, the clotting cascade has been adopted as a poster child by the Creationists. They looked for the most complex of systems in humans, and then represented it in ways that are disingenuous and lacking in intellectual gravitas. That is their purview. But the clotting cascade, having survived 600 million years and counting, has seen it all. It will continue its inexorable path up the mountain, to even greater heights, taking advantage of a beneficial mutation here and there, oblivious to all the commentary. Now that’s a sight to behold!

 

[Tiger]

Regardless, it's still poor design. Certainly not intelligent. No explanation for it other than the one given by Biologists holds any water.

The poor design that you ascribe is a strawman. It has plenty of functionality.

Have you any awareness of the list of vestigial organs from the 1970’s that are now no longer considered vestigial?

The recurrent laryngeal nerve effectively accomplishes its primary function of innervating the larynx and facilitating crucial physiological processes like breathing, swallowing and vocalisation. That’s not vestigial in any way.

 

[Myles O'Reilly]

As I asked you some months ago Tiger, why the need to give the beast such a long neck in the first instance? Why not design it to eat stuff lower to the ground?

And why not put an eye above its arsehole so when bent down drinking water it'd be able to see the approach of a Lion from behind?

 

[Tiger]

Here you are.

The slow and steady march up the gradual incline is no picnic. Passage is governed by a series of unforgiving rules, or laws of nature. For one, every step must confer a survival or reproductive advantage. Second, the path is one-way; a species or trait cannot reverse course and get worse as a means towards eventual improvement. Finally, there are no sudden leaps or precipitous increases in ordered complexity.

Today, the coagulation mechanism metaphorically rests at the summit of the mountain. For those of us who studied the clotting cascade in medical school, we are fully aware of its awe-inspiring, not to mention intimidating, complexity. How remarkable, most of us would agree, that the mechanism arose through step-by-step modification and natural selection over the eons… what a marvel of evolutionary sculpting!

Creationists have a different take. My goodness, they claim, the clotting cascade is so complex that it could not possibly have arisen from small beginnings by a gradual series of incremental changes. Nope, they conclude, the clotting cascade is irreducibly complex. Like a mousetrap, the proper functioning of the coagulation mechanism is all or nothing: take away a single component and the whole system fails. The only route to the summit is by way of the cliff, and the only way up the cliff is on the shoulders of a divine creator.

Michael Behe, a Professor of Biochemistry at Lehigh University devoted an entire chapter in his book, Darwin’s Black Box, to the clotting cascade.2 In his book, he states that, “Blood coagulation is a paradigm of staggering complexity that underlies even apparently simple bodily processes. Faced with such complexity beneath even simple phenomena, Darwinian theory falls silent”. Behe went on to write: “The bottom line is that clusters for proteins have to be inserted all at once into the cascade. This can be done by postulating… the guidance of an intelligent agent.”

How do we even begin to address these assertions? We can ignore them, but that doesn’t help to mitigate the published misconceptions and deceptions, so readily accessible in the popular press. The Biological Sciences Department page on the Lehigh University website has a prominent disclaimer: “While we respect Prof. Behe’s right to express his views, they are his alone and are in no way endorsed by the department. It is our collective position that intelligent design has not basis in science”.3 Ouch.

Rather than censoring Behe, let’s take him on. Not because there is any merit to his position, but because, as noted by a famous biologist from the early 20th century, “nothing makes sense except in the light of evolution”.4 The first point to make is that irreducible complexity, which is defined as a system with several interacting parts that ceases to function when any one component is removed, is not evidence of divine creation. Biology is full of irreducible complexity – just think of the many single gene knockouts in mice that lead to embryonic lethality – but the interlocking nature of complex designs is as much a product of evolution as the single components themselves. Indeed, biological systems display non-linear dynamics and emergent properties such that the system cannot be understood by the studying the individual parts in isolation.

But does the coagulation system even meet the definition of irreducible complexity? The answer is no. The clotting cascade consists of sequential activation of a series of proenzymes or inactive precursor proteins (zymogens) to active enzymes. There are two arms to the clotting cascade: intrinsic and extrinsic. Both converge on the common pathway, which ultimately promotes thrombin generation and fibrin formation.

Humans who are deficient in one or another zymogen often have bleeding diatheses, but many can live a normal life and reproduce. Well, you might argue, these patients have some residual activity of their deficient factor, and perhaps that’s enough to keep them alive. However, genetically engineered mice who have complete loss of certain clotting factors, are also viable. Perhaps the most surprising is the mouse that lacks fibrinogen. They cannot make any fibrin plugs, yet they are viable, provided they are not subject to surgical procedures.5 The fact that a mammal can survive without any fibrinogen is the antithesis of irreducible complexity.

Second, despite the Creationists contention that the clotting cascade arose all at once, the evidence speaks otherwise. By examining the genomes of various classes of extant vertebrates, it is possible to infer the evolutionary history of the coagulation system. We learn that the clotting cascade first arose in an ancestral vertebrate some 600 million years ago. Moreover, the clotting cascade, as we recognize it in humans, did not evolve all at once. The extrinsic system appeared first (in jawless fish), followed by FIX (in jawed fish) and then the contact system (in amphibians) (see Figure below). This sequence of events is backed by strong biological plausibility: clotting is always initiated by the FVII of the extrinsic cascade, is amplified by FIX of the intrinsic pathway and is further accelerated by FXI, which lies downstream of the contact pathway.

The clotting cascade is absent in invertebrates and present (in one form or another) in all vertebrates. Therefore it evolved in the ancestral vertebrate some 600 million years ago, over a short time frame of 50-100 million years. The Creationists and their ilk have argued that the clotting cascade could not possibly have evolved over such a short period of time by step-by-step modification. This is what Dawkins refers to as the argument from personal incredulity: “Wow, so much to assemble in such a short period of time, there is no other explanation than Divine intervention!” Such intellectual laziness does little to further the discussion. Who is to say what is too short in evolutionary time? The fact that the clotting cascade arose quickly speaks to the power and versatility of gene duplications and exon shuffling and explains the high degree of homology between the various components of the clotting cascade.

Sadly, the clotting cascade has been adopted as a poster child by the Creationists. They looked for the most complex of systems in humans, and then represented it in ways that are disingenuous and lacking in intellectual gravitas. That is their purview. But the clotting cascade, having survived 600 million years and counting, has seen it all. It will continue its inexorable path up the mountain, to even greater heights, taking advantage of a beneficial mutation here and there, oblivious to all the commentary. Now that’s a sight to behold!

View attachment 5379

You’ve simply copied and pasted a googled response. Can you put this in your own words or shall I break it apart for you?


The choice is yours

 

[Fishalt]

The poor design that you ascribe is a strawman. It has plenty of functionality.

Have you any awareness of the list of vestigial organs from the 1970’s that are now no longer considered vestigial?

The recurrent laryngeal nerve effectively accomplishes its primary function of innervating the larynx and facilitating crucial physiological processes like breathing, swallowing and vocalisation. That’s not vestigial in any way.

So we're just going to ignore my last post? That's what we're doing. OK.

The issue isn't the functionality of the nerve. It does what it does. The issue is that there's absolutely no reason for it to be designed in such a way. In the cited example of the Giraffe, it is akin to a person who lives opposite a corner store walking around the block to buy a bottle of milk rather than just directly crossing the street.

Like many other questions about our anatomy, it can be explained by embryology. During development, the head and the heart originate closely together, and so the RLNs develop close to the aorta. The formation of the neck pushes the head and heart apart, dragging the vessels down into the thorax, along with the RLNs. The RLNs will elongate to maintain its connection to the larynx while being hooked around the vessels of the heart, and so the U-turn is formed.

As much as necks vary, the RLN follows suit. From fish, to humans, to giraffes, the nerve makes a bigger and bigger U-turn in order to reach the larynx. When it comes to humans, the 10cm detour is already strange. But because of their long necks, giraffes are the go-to example since their RLNs will approach 5 meters in length in larger animals.

 

[Fishalt]

You’ve simply copied and pasted a googled response. Can you put this in your own words or shall I break it apart for you?


The choice is yours

Of course I have. I don't see how this is in any way different to your copypasting youtube videos with sensationalist clickbait titles published by various religious cranks. I'm not even sure I understand the tone of the accusation--are credulously operating under the premise that I have (or should have) stored in my mental database the specifics and particulars of the evolution of mammalian blood clotting?

I'm not sure why I'd need to rewrite it. It's well-written, concise and intelligible.

 

[clarke-connolly]

Oh dear. We're not back to the exploding Giraffe heads are we?

In fairness Dawkins does not help, himself / his ideas, by being such an arrogant Gob-Shite ! !

 

[Fishalt]

In fairness Dawkins does not help, himself / his ideas, by being such an arrogant Gob-Shite ! !

I actually agree with this. He's more interesting to me as a biologist than he is as an antireligious crusader. I can see how one could be driven to it by dogmatists like Tiger and Zipporah though.

 

[Mad as Fish]

Nice straw man you've constructed there.

There is no historical evidence that man believes in deities as some form of cope. It's almost like you've never read Augustine or Aquinas.

And the fact remains, there is no proven biological mechanism to support the theory of evolution. The real cope is out there, chiefly manifested by people who hang onto the doorframes of a failed worldview by claiming adaption is evolution . It isn't.

But has mankind ever been as aware of the sheer vastness of its ignorance as it is now?

Presently, we find ourselves with marvellous tools of discovery, as we never have possessed before, and yet those engaged in genuine scientific endeavour become more deeply aware that we know so little.

Past philosophers might never have experienced this doubt, their art was trying to make sense of the world as they knew it and it was made of two basic elements, the real and the spiritual,

My argument is that now we can recognise a space between these two parts, a chasm full of knowledge that we have yet to assimilate. That is not a cope mechanism, it is a thirst to know more, to give reason to what we see and experience about us.

Ascribing events and situations to deities because no other explanation was forthcoming is as old as man’s recorded history itself.

 

[Fishalt]

But has mankind ever been as aware of the sheer vastness of its ignorance as it is now?

Presently, we find ourselves with marvellous tools of discovery, as we never have possessed before, and yet those engaged in genuine scientific endeavour become more deeply aware that we know so little.

Past philosophers might never have experienced this doubt, their art was trying to make sense of the world as they knew it and it was made of two basic elements, the real and the spiritual,

My argument is that now we can recognise a space between these two parts, a chasm full of knowledge that we have yet to assimilate. That is not a cope mechanism, it is a thirst to know more, to give reason to what we see and experience about us.

Ascribing events and situations to deities because no other explanation was forthcoming is as old as man’s recorded history itself.

Every culture more or less has their own creation fairytale. Pointing up at the sky and prescribing magical explanations for the phenomenological in lieu of scientific explanations is par for the course. Western (Middle Eastern) varieties just happen to be far more sophisticated because the complexity of religions tracks with technological development, as is to be expected I suppose. Europe refined Christianity a whole lot.

Great documentary here if you have that captures the process of a previously uncontacted Amazonian tribe coming to grips with living in the current century. What I found especially interesting is that after only a few months living in an encampment, they abandoned their tradition (presumably thousands of years old) of getting about mostly naked in the Jungle. When queried about this, they would simply say they had become 'Too embarrassed' not to wear clothing. Amazing.

https://www.youtube.com/results?search_query=documentary+uncontacted+tribe+brazilk

 

[PlunkettsGhost]

But has mankind ever been as aware of the sheer vastness of its ignorance as it is now?

Interesting, isn't it? The more technologically advanced we become, the more grows our sense of wonder at the complexity and symbiotic nature of the cosmos and our world. That Victorian/Edwardian arrogance related to man's ability to categorize and control his environment is vanishing.

Denton's book - Nature's Destiny, is a fascinating catalogue of all the molecular and cosmic balances that are required for life to exist, from the molecular/thermal qualities of water, to the Sun's precise distance from us, to name but two. Thousands of seemingly unconnected things all hang together to create the knife-edge balance required for life.

Electron microscopes and Micro biological chemistry have dumbfounded us as to the extreme complexity of 'basic' cellular activity, and so we find our selves today unable to account for the mechanisms that would have created such cellular complexity, in a near instantaneous moment.

Abiogenesis is a subject matter that most proponents of evolution wont touch with a long pole these days.

 

[Mad as Fish]

Interesting, isn't it? The more technologically advanced we become, the more grows our sense of wonder at the complexity and symbiotic nature of the cosmos and our world. That Victorian/Edwardian arrogance related to man's ability to categorize and control his environment is vanishing.

Denton's book - Nature's Destiny, is a fascinating catalogue of all the molecular and cosmic balances that are required for life to exist, from the molecular/thermal qualities of water, to the Sun's precise distance from us, to name but two. Thousands of seemingly unconnected things all hang together to create the knife-edge balance required for life.

Electron microscopes and Micro biological chemistry have dumbfounded us as to the extreme complexity of 'basic' cellular activity, and so we find our selves today unable to account for the mechanisms that would have created such cellular complexity, in a near instantaneous moment.

Abiogenesis is a subject matter that most proponents of evolution wont touch with a long pole these days.

Abiogenesis, not a word I had encountered before but it certainly moves the goalposts with regard to the spontaneous origin of life.

Like most of us I had been brought up to believe in the warm soup and lightening hypothesis, but just a few minutes browsing the above strips bare the the vulnerability of that theory to clinical examination.

I need to go away and read further.

 

[PlunkettsGhost]

Abiogenesis, not a word I had encountered before but it certainly moves the goalposts with regard to the spontaneous origin of life.

Like most of us I had been brought up to believe in the warm soup and lightening hypothesis, but just a few minutes browsing the above strips bare the the vulnerability of that theory to clinical examination.

I need to go away and read further.

Yes, in light of what we now know about the extreme and necessary complexity of the most basic building block of life - the cell, the lightning bolt theory now takes on the ring of a scientific mythos/creation tale. More irony.

 

[PlunkettsGhost]

A short review of Nature's Destiny:

Denton, as a biologist, believes in the mechanism of natural selection, unware presumably, of the mathematical problems that have plagued this theory for decades. Still, even here, he recognizes the obvious patterns of design and intelligence in the universe.


View: https://www.youtube.com/watch?v=IIVe0tb1EQM

 

[PlunkettsGhost]

As Dawson has so amply pointed out from his rage-cage:

Evolutionists have no interested in the actual origins of life. Through the power of imagination, they accept the Norse tale of the lightning bolt as obvious fact, and simply move on. Until of course you point out there is no evidence of speciation via natural selection either. They then move on from that and hold onto the crumbling door-frames of micro-adaption as being evidence for macro-evolution. An obviously laughable, desperate situation.