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Whale Evolution? Darwinist ‘Trawlers’ Have Every Reason To Be Concerned

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“Of all whale species, by far the noisiest, chattiest, most exuberant, and most imaginative is the humpback. It is the noisemaker and the Caruso of the deep, now grating like an old hinge, now as melodious as an operatic tenor” (1). These were the words of the late oceanographer Jacques Cousteau in his epic volume Whales, originally written in French under the more descriptive title La Planete Des Baleines. The male humpback in particular had been a source of fascination for Cousteau’s exploration team precisely because of its exquisite song-making capabilities. Star Trek aficionados will no doubt remember the long-range distress calls of these ocean-faring giants in the movie blockbuster The Voyage Home.

Humpbacks can be heard for hundreds or even thousands of kilometers creating discernible noise sequences or ‘themes’ that can last as long as 20-30 hours (1,2). The available repertoire of vocalizations requires that “bursts of air” be channeled up from the lungs and through the trachea (3). The frequency range of these vocalizations is formidable- 8-4000 Hz (compared to 80-1300 Hz for a singing human; (4)). While certain sounds might serve to maintain contact between distant herds (2) others are clearly used to attract mates in the shallow breeding grounds of the tropics (5).

The sperm whale’s characteristic clicking has likewise been intensely studied and marine biologists have in the last decade described this creature’s ‘pneumatic sound generator’ in great detail (6). Usual clicks serve for echo location while so-called ‘coda’ clicks are used for maintaining the “complex social structure in female groups” (6). Remarkably the amount of air used to make each click is so small that even at depths of 2000 m, where the air volume is significantly reduced, sperm whales can phonate successfully (6). The mechanism of sound generation is exquisitely selective for the two modes of communication: “the marked differences between coda clicks and usual clicks are caused by differential sound propagation in the nasal complex” (6).

Other whale species are known to ‘talk to each other’: blue whales, fin whales, rights and bowheads all display the use of what has tentatively been called a rudimentary language (7). Equally captivating is the auditory apparatus that picks up these sounds (8). Unlike terrestrial mammals, whales sport freely-vibrating ossicles in the middle ear for more sensitive distance hearing:

“The bones of the middle ear, although fused to each other, are not directly connected to the rest of the skull; they are suspended from it by means of ligaments. All around them is a complex network of cavities and sinuses filled with a foamy mucus that further insulates the ear from the skull and provides yet another means by which whales filter out all but the essential sounds.”(9)

What are we to make of the evolutionary origins of these key designs? In the summer of 2009 a seminal publication in the journal Mammalian Biology provided fodder for one popular idea (10). Using the aquatic escape behavior of Bornean mouse deer as primary evidence for their claims, researchers from Indonesia and the Australian National University in Canberra proposed that whales might have descended from ancient members of the ruminant family tragulidae which today includes cattle, sheep, goats and deer (11). Local villagers have observed tragulids submerging themselves in rivers and streams for over five minutes at a time as a way of eschewing would-be predators (10).

The Australian-Indonesian publication came hot on the heels of a cladistic study that claimed to have found a whale ‘sister group’ called Indohyus – “a middle Eocene raoellid artiodactyl from Kashmir, India” (10, 12). The overarching conclusion of this earlier work was nothing short of profound:

“Our analysis identifies raoellids as the sister group to cetaceans and bridges the morphological divide that separated early cetaceans from artiodacyls.” (12)

We might therefore reasonably expect that the hearing and vocalization of modern cetaceans could be drawn into a gradual evolutionary sequence, perhaps going as far back as the land-sea transitioning mammals from which they are supposed to have been derived. But like so many evolutionary just-so stories, the devil is in the details. Indeed Darwinists admit that significant differences in the morphology of sensory organs make cetaceans unique (12).

In 2004 a group headed by professor of anatomy Hans Thewissen published what appeared to be the definitive answer on the evolution of whale hearing (13). Their ‘integrated interpretation of evolving sound transmission mechanisms’ came as a result of fossils that were collected from 35-50 million year-old deposits (13). The base specimen of their cladistic interpretation, a 50 million year old fossil of a terrestrial mammal called pakicetus, benefited from bone conduction of sound through a loosely suspended tympanic bone (13). Later aquatic mammals such as remingtoncetus and protocetus possessed large so-called mandibular fat pads that further improved bone-mediated sound transmission (13). For all three phyletic groups a terrestrial auditory structure called the external meatus allowed efficient capture of airborne sounds (13). Thewissen’s final chronological group, the basilosauroids, sported yet one further innovation- air-filled sinuses that acoustically isolated the ear from the rest of the skull (13).

The most striking omission in the above sequence, and perhaps the most important of all, is the explanation for how a fleeting mouse deer somehow adapted to the acoustic rigors of underwater living. A five minute escapade in the shallows of a river is a far cry from the mate searches that would have been so vital for an aquatic lifestyle. Pakicetus was in fact a fast-running, land-dwelling long-necked quadruped (more like a dog than a deer) that lacked any sort of sub-aquatic anatomy (14, 15). Indeed one alternative interpretation of the data is that the pakicetus middle ear structure was more consistent with what one might expect for a subterranean habitat in which the head is in direct contact with the ground (14).

While Remingtoncetus was undoubtedly a four-legged semi-aquatic mammal that had a long slender snout, small eyes and ears and an overall size perhaps no bigger than a sea otter (16, 17), the above descriptive of the origins of its auditory innovations fits more in line with what one might expect for, say, a saltationist view of life than any sort of gradual evolutionary process. The same can be said of the supposed transition from protocetus to basilosauroids. In fact the fossil evidence reveals that in remingtoncetus the foundations of the modern whale underwater auditory mechanism had already been realized (13). Ironically the most convincing set of ear transitional forms in the whale evolutionist’s armory- that of the decrease in size of the semicircular canal system of the inner ear (involved in balance) – only shows evolution bringing about small changes to already existing functional innovations (15).

Hippopotamids are of course hot favorites for the title of the closest living terrestrial relatives of whales (18, 19). Like whales, modern hippos are furnished with bone-mediated hearing and exhibit effective underwater communication (18). Still, morphology-based phylogenies to-date have yielded conflicting results and the identification of intermediates that supposedly spanned the divide between hippos and the common ancestor is controversial (20). Different analyses show anywhere between 3 and 40 million years of unrecorded evolution depending on which sister groups one chooses to grab along the way (20).

Over a decade ago one high school biology textbook asserted that there were no clear transitional fossils linking land mammals to whales (21). Such a position has been upheld by the most recent peer-reviewed literature. In fact hypotheses on the evolution of sound generation in whales and delphinids hinge upon the selective “drivers” that purportedly brought about change (eg: hunting, increased sociality, predator avoidance) while leaving out the mechanistic details of how such change took place (22, 23, 24). In contrast, the co-integrated nature of whale sound transmission, both in its vocalization and capture, has led some to the inference that intelligent rather than mindless design is at play. As one review noted:

“The anatomical structure, biological function, and way of life of whales are so distinctly different from those of terrestrial mammals that they cannot possibly have evolved from the latter by small genetic changes; aquatics require the simultaneous presence of all their complex features to survive. Perfect acoustical and other constructions are required for their serenades and way of life in the vastness of the ocean; they could only exist from a detailed preliminary plan. Employing sounds to allure their mates has another interesting feature, considering the entirety of the animal kingdom. Although each species emits sound signals that resemble signals of other species, the animals never mistake the sounds for those of other species…Harmony between sounds and sound-receiving organs likewise presupposes the…requirement of simultaneous appearance, while excluding the possibility of gradual evolution.” (8)

In short, the latest evidence on whale communication cuts deep into the fishing nets of evolutionary dogma. Darwinist trawlers have every reason to be concerned.

Literature Cited
1.Jacques Cousteau and Yves Paccalet (1986) Whales, W.H. Allen & Co, London, pp. 236-38.

2.Eduardo Mercado III (1998) Humpback Whale BioAcoustics: From Form To Function, PhD thesis, University of Hawaii, http://www.acsu.buffalo.edu/~emiii/diss.pdf p.16.

3. Ibid p.25.

4. Ibid p.37.

5. Planet Earth Series: Shallow Seas, Narrated by David Attenborough, BBC Video, 2008.

6. P. T. Madsen, R. Payne, N. U. Kristiansen, M. Wahlberg, I. Kerr and B. Mohl (2002) Sperm whale sound production studied with ultrasound time/depth-recording tags, The Journal of Experimental Biology, Vol 205, 1899-1906.

7. Jacques Cousteau and Yves Paccalet (1986) Whales, W.H. Allen & Co, London, p.234.

8. Balazs Hornyanszky and Istvan Tasi (2009) Nature’s IQ: Extraordinary Animal Behaviors That Defy Evolution, Torchlight Publishing, Badger, CA, pp.102-104.

9. Jacques Cousteau and Yves Paccalet (1986) Whales, W.H. Allen & Co, London, p.161.

10. Erik Meijaarda, Umilaela, GehandeSilva Wijeyeratne (2009), Aquatic escape behaviour in mouse-deer provides insight into tragulid evolution, Mammalian Biology, doi:10.1016/j.mambio.2009.05.007

11. Matt Walker (2009) Aquatic Deer And Ancient Whales, BBC Earth News, 7th July, 2009, See http://news.bbc.co.uk/earth/hi/earth_news/newsid_8137000/8137922.stm

12. J. G. M. Thewissen, Lisa Noelle Cooper, Mark T. Clementz, Sunil Bajpai & B. N. Tiwari (2007) Whales originated from aquatic artiodactyls in the Eocene epoch of India, Nature, Vol 450, pp.1190-1194.

13. Sirpa Nummela, J. G. M. Thewissen, Sunil Bajpai, S. Taseer Hussain, Kishor Kumar (2004) Eocene evolution of whale hearing, Nature, Vol 430, pp.776-778.

14. J. G. M. Thewissen, E. M. Williams, L. J. Roe & S. T. Hussain (2001) Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls, Nature, Vol 413, pp.277-281.

15. F. Spoor, S. Bajpai, S. T. Hussain, K. Kumar & J. G. M. Thewissen (2001) Vestibular evidence for the evolution of aquatic behaviour in early cetaceans, Nature, Vol 417, pp.163-166.

16. Remingtoncetidiae, See http://www.neoucom.edu/DEPTS/ANAT/Remi.html

17. Sunil Bajpai and J. G. M. Thewissen (2000) A new, diminutive Eocene whale from Kachchh (Gujarat, India) and its implications for locomotor evolution of cetaceans, Current Science, Vol 79, pp.1478-1482, See http://tejas.serc.iisc.ernet.in/currsci/nov252000/1478.pdf

18. The Animal Communication Project, See http://acp.eugraph.com/elephetc/hippo.html

19. Whale and hippo ‘close cousins’ BBC News, Monday, 24 January, 2005, See http://news.bbc.co.uk/2/hi/science/nature/4204021.stm

20. Jean-Renaud Boisserie, Fabrice Lihoreau, and Michel Brunet (2005) The position of Hippopotamidae within Cetartiodactyla, Proc. Natl. Acad. Sci, Vol 102, pp.1537-1541.

21. Percival Davis, Dean H Kenyon, Charles Thaxton (1993) Of Pandas And People: The Central Question Of Biological Origins, Haughton Publishing Company, Richardson, Texas.

22. Laura J May-Collado, Ingi Agnarsson, Douglas Wartzok (2007) Phylogenetic review of tonal sound production in whales in relation to sociality, BMC Evolutionary Biology 2007, Vol 7, p.136, See http://www.biomedcentral.com/content/pdf/1471-2148-7-136.pdf

23. Migrating Squid Drove Evolution Of Sonar In Whales And Dolphins, Researchers Argue
http://migration.wordpress.com/2007/09/15/squid-migration-drives-whale-sonar-evolution/

24. Morisaka T, Connor RC (2007) Predation by killer whales (Orcinus orca) and the evolution of whistle loss and narrow-band high frequency clicks in odontocetes, Journal Of Evolutionary Biology, Volume 20, pp.1439-58.

Comments
Joseph:"If it is wrong then edit it. " You are unsure if it is wrong? It is your reference I just assumed that a vetting of the accuracy of the information one posts would be in order. To each their own I suppose! Joseph:"Nested hierarchies are built on characteristics." If taxonomy is based on characteristics and nested hierarchies are based on characteristics if seems to follow that a discussion of taxonomy is reasonable when speaking about whale evolution and nested hierarchy. Which gets back to the question of where whales, mice, and fish fit into the nested hierarchy and what chracteristics are used for that placement.Acipenser
January 5, 2010
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Acipenser:
Are you saying that nested hierarchy construction is not based on characteristics?
Nested hierarchies are built on characteristics. That is what I have been saying for decades. Zachriel, OTOH, is saying that descent with modification leads to a nested hierarchy. It does not for all the reasons provided. And as for wikipedia, I cite it because it seems to be a favorite reference of evolutionists. If it is wrong then edit it.Joseph
January 5, 2010
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Nakashima, Did you read the papers? Both are speculation based on the assumption. Neither one demonstrates anything. IOW no one took an embryo of one animal, added HOX genes and got a different body plan as a result.Joseph
January 5, 2010
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Joseph:"Some other cold-blooded creatures use internal mechanisms to maintain body temperatures significantly above the ambient level" Do not all wamr-blooded creatures use internal mechanisms to maintain body temperatures significantly above ambient levels? Joseph:(your reference states the following)“Warm-blooded” sharks (e.g. mako and white sharks), to minimize heat loss through their gills, pass their blood through rete mirabile heat exchangers before it enters into the gills and after it exits from them: Veins are right next to arteries and thus extract heat from the arteries and carry it back into the body." There is a fatal error in that passage that hopefully you are aware of and recognize that you should, perhaps, consult an accurate reference to cite. Jospeh:"Taxonomy is based on CHARACTERISTICS." Are you saying that nested hierarchy construction is not based on characteristics? Seems to me that that is not the case at all. Perhaps I have misunderstood you and hopefully you can explain how it works that taxonomy uses characteristics and nested hierarchy does not use characteristics.Acipenser
January 5, 2010
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Mr Joseph, So you say yet there isn’t any evidence to support your claim. Don't tell the folks who wrote Gene duplications and the origins of vertebrate development or Hox genes and chordate evolution.Nakashima
January 5, 2010
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I don’t want to discuss taxonomy. osteonectin:
Why not? We can learn quite something from Taxonomy. E.g., when Thylacine is being discussed as a menber of Canidae
Taxonomy doesn't have anything to do with descent with modification.Joseph
January 5, 2010
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So what part of the theory of evolution prevents crossing? Zachriel:
It’s an *observation* that some organisms don’t cross.
So there isn't anything in the theory that prevents it. Got it. Also the Creation model states that there won't be any crossing.
There’s an entire chapter concerning hybridization and degrees of reproductive isolation in Darwin’s Origin of Species.
The theory starts with reproducing organsism so really doesn't have much to say about it. If organisms could readily inter-breed the theory would be OK with that. You guys would just say "See- we are all related!"Joseph
January 5, 2010
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Zachriel sez:
What’s wrong is that you misrepresented the Theory of Evolution. When provided evidence that you were wrong, you refused to correct yourself. Whether or not you agree with the Theory of Evolution, it is not appropriate to misrepresent it in order to strike down a strawman.
Let's see- you cannot provide any evidence to support your claim so therefor I misrepresenting the theory of evolution? So that we are clear: You have not presented any evidence that evolution/ descent with modification prevents crossing.
If you don’t want to talk about whales and their traits, no one can make you. This thread is about whale evolution. The Theory of Evolution asserts Common Descent, and taxonomy is crucial evidence in support of this theory.
More empty bloviation. Yes this thread is about whale evolution. Taxonomy doesn't have anything to do with whale evolution. Taxonomy is based on CHARACTERISTICS. You are trying to argue descent with modification, which we all know does not lead to a nested hierarchy. IOW the observed nested hierarchy should be evidence against your position. That you refuse to understand taht proves that you arten't in any position to discuss the evidence.Joseph
January 5, 2010
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From the fount of all knowledge, Wikipedia: Temperature control in cold-blooded animals:
Some other cold-blooded creatures use internal mechanisms to maintain body temperatures significantly above the ambient level: Tuna and Swordfish. Fish have long been thought to be cold blooded. Tuna and swordfish dive deep into the ocean where the water is very cold. Swordfish are able to raise the temperature of their brains and eyes, which allows faster eye movements when hunting. Tuna are able to warm their entire bodies through a heat exchange mechanism called the rete mirabile, which helps keep heat inside the body, and minimizes the loss of heat through the gills. They also have their swimming muscles near the center of their bodies instead of near the surface, which minimises heat loss. "Warm-blooded" sharks (e.g. mako and white sharks), to minimize heat loss through their gills, pass their blood through rete mirabile heat exchangers before it enters into the gills and after it exits from them: Veins are right next to arteries and thus extract heat from the arteries and carry it back into the body.
Or is wikipedia only OK when you think that it supports you?Joseph
January 5, 2010
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BTW Zachriel, If you think that descent with modification leads to a nested hierarchy then you are not in any position to assess any evidence. IOW we need to clear that hurdle before we can move forward.Joseph
January 5, 2010
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Nakashima:
Duplicate sets of Hox genes and you can build more complicated body plans.
So you say yet there isn't any evidence to support your claim.Joseph
January 5, 2010
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Zachriel, Linneaus was a Creationist searching foir the Created Kinds. Taxonomy- the observed nested hierarchy- was first was as evidence for a Common Design.
The claim is that whales could not have evolved by small genetic changes.
And you don't have any evidence that the transformations required are even possible. Also sexual reproduction pretty much squashes Common Descent.Joseph
January 5, 2010
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Mr Joseph, in re gills and cold bloodedness: That define fish. And I am not the one who said it. You can look it up if you want. (Onlookers, you knew I would, with that kind of a straight line...) From the fount of all knowledge, Wikipedia: A fish is any aquatic vertebrate animal that is covered with scales, and equipped with two sets of paired fins and several unpaired fins. (BTW, here the Bible agrees that fins and scales are the determining characters of fish.) The next time you are wondering what to write and your Magic 8 Ball says "Make it up!", give it another shake until "Use your internet connection" floats to the top. It really works!Nakashima
January 5, 2010
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Mr Joseph, What knock-out experiments demonstrate the transformations required are even possible? Every knockout experiment proves it is possible. Possible means the mechanism exists. Darwin posited variable and heritable traits, and Mendel proved they exist. Duplicate sets of Hox genes and you can build more complicated body plans. By continuing to ask "are they even possible" you are singing a few bars behind the choir. When Drs. Dembski and Meyer ask the question about probabilistic resources, they are already admitting that, yes, they are possible.Nakashima
January 5, 2010
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The claim is that whales could not have evolved by small genetic changes. This is a direct reference to the Theory of Evolution. Hence, it is entirely appropriate to consider that theory in detail. To do so requires establishing Common Descent. To do that we must first establish a suitable taxonomy.
Zachriel: Do whales group best with mice or fish? Joseph: I don’t want to discuss taxonomy.
Hence not wanting to discuss the evidence for the Theory of Evolution. By the way, Linnaeus placed whales with mammals a century before Origin of Species. Linnaeus, Systema Naturae. Volume 1. 10th edition, Laurentii Salvii, Holmiae, 1758.Zachriel
January 5, 2010
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Design is a much simpler explanation that an accumulation of magical mystery mutations. Nakashima-san:
Indeed, knockout experiments are much more complicated than poof.
What knock-out experiments demonstrate the transformations required are even possible? What knock-out experiments show that an accumulation of genetic accidents can build useful complex protein macinery and change body plans?Joseph
January 5, 2010
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Nakashima-san:
Wilful misunderstanding is not refutation. The question of defining characters cannot be decided simply on the basis of the adult body.
The willfull misunderstanding is all yours. Neither whales nor micehave gills during any stage of development nor life.
You posited gills and cold bloodedness as two characters that would define a hierarchy.
That define fish. And I am not the one who said it. You can look it up if you want.
Since amphibians have gills and are cold blooded, do you agree that it is legitimate to posit a hierarchy that places amphibians and modern fish under some common ancestor?
A hierachy is different than a nested hierarchy. And there still isn't any data which demonstrates that such a transformation is even possible.Joseph
January 5, 2010
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Mr Joseph, Design is a much simpler explanation that an accumulation of magical mystery mutations. Indeed, knockout experiments are much more complicated than poof. Occam's Razor has slit the throat of methodological naturalism. You shall be remembered as the Sweeney Todd of science.Nakashima
January 5, 2010
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Mr Joseph, Your position that these structures are gill slits has been refuted. Wilful misunderstanding is not refutation. The question of defining characters cannot be decided simply on the basis of the adult body. You posited gills and cold bloodedness as two characters that would define a hierarchy. Since amphibians have gills and are cold blooded, do you agree that it is legitimate to posit a hierarchy that places amphibians and modern fish under some common ancestor? Or is the tadpole related to fish but the frog not related?Nakashima
January 5, 2010
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Acipenser
In order for me to respond appropriately I would need to know and understand your definition of “characteristic” versus the one you use for “defined characteristic”.
Skin color is a characteristic. However it is not a defining characteristic for humans.
I don’t think you can use descent as a taxinomic criteria. You could infer descent given a collection of characteristics, however.
Seeing that descent does nit say that characteristics will collect why would anyone make such an inference? As I said before with evolution characteristics can be lost. Nothing prevents that from happening.
You could try that but you would need to provide an explanation of the how this design mechanism cropped up in this group of creatures and is not present in other sets of creatures.
Design is that explanation. If you want to say "descent" then you have to demonstrate that the transformations required are even possible.
Of course the explanation would have some specificity to it otherwise we would need to resort to Occam’s razor and resort to the simplest explanation that explains the presence of these structures.
Design is a much simpler explanation that an accumulation of magical mystery mutations.Joseph
January 5, 2010
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Nakashima-san:
Mice and whales have structures at the same spot, using the same genes as fish, that preserve a function of gills in fish.
Common design can explain that.
Of course these are not the gills of modern fish, and no one is arguing that mice and whales are descended from modern fish.
If you want to argue that mice and whales descended from any type of fish you need something that demonstrates the transformations required are even possible.
However, your position that these structures which they do have are not related to gills is absurd, and not one you can support from the scientific literature.
Your position that these structures are gill slits has been refuted. Stop acting like a baby and take it like a man. And if you want to be taken seriously you shouldn't use refuted arguments. Perhaps someone should take the genes you think are the same, modify them and see if we canb get a mouse or a whale with gills.Joseph
January 5, 2010
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Mr Joseph, Mice and whales have structures at the same spot, using the same genes as fish, that preserve a function of gills in fish. Of course these are not the gills of modern fish, and no one is arguing that mice and whales are descended from modern fish. However, your position that these structures which they do have are not related to gills is absurd, and not one you can support from the scientific literature. I also found your "I was just testing you" comment quite amusing, I haven't seen it used by someone that wanted to be taken seriously in some time.Nakashima
January 4, 2010
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Joseph:"If descent is not a defining characteristic then it is obvious that descent with modification does not predict a nested hierarchy." In order for me to respond appropriately I would need to know and understand your definition of "characteristic" versus the one you use for "defined characteristic". Could you explain the difference to me as I previously requested? I don't think you can use descent as a taxinomic criteria. You could infer descent given a collection of characteristics, however. Joseph:"And about the references to cold-bloodedness and fish- it shows that they use tricks to raise their body temp." Tricks? Seems like a lot of animals (you and I included)all use tricks to regulate their internal body temperature greater than their environment. It certainly is an advantageous trick for all species that use these tricks. Joseph:"Also this: The embryos of mice, whales, and fish (as well as all vertebrate embryos)possess pharyngeal pouches a trait no other group of animals share. can be used as evidence for a common design." You could try that but you would need to provide an explanation of the how this design mechanism cropped up in this group of creatures and is not present in other sets of creatures. Of course the explanation would have some specificity to it otherwise we would need to resort to Occam's razor and resort to the simplest explanation that explains the presence of these structures.Acipenser
January 4, 2010
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Acipenser, If descent is not a defining characteristic then it is obvious that descent with modification does not predict a nested hierarchy. Also this:
The embryos of mice, whales, and fish (as well as all vertebrate embryos)possess pharyngeal pouches a trait no other group of animals share.
can be used as evidence for a common design. All fish have gills and gills are a defining characteristic of fish. Neither mice nor whales have gills thereby breaking the containment requirement for nested hierarchies. And about the references to cold-bloodedness and fish- it shows that they use tricks to raise their body temp.Joseph
January 4, 2010
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Joseph:"As for cold-bloodedness- nice of you to ignore my references." I didn't ignore your reference but did note that it is very superficial in addressing the endothermic mechanisms used by fish to elelevate their body temperature above ambient temperatures. What did you find particulary striking about your reference? If endothermy does not consitute warm-bloodedness what does? In otherwords how many degrees must an animal actively (versus passive sun-bathing or generalized large mass) maintain their internal body temperature above the environment they inhabit in order to be classified as being warm-blooded versus cold-blooded. Joseph:"All fish have gills." and not all fish use gills for respiration and as I pointed out earlier some can even drown if held underwater. Jospeh:"The observed nested hierarchy is based on characteristics" True, and are these characteristics not defined? In otherwords what is the differnece between a 'characteristic' and a 'defined characteristic'? I also have not seen anyone (outside of you/Joseph) claiming that 'descent' is a defining characteristic used for taxonomic classification of any species. Joseph:"So what?" I suppose it could be simply a coincidence but that would be what would be expected and predicted based on common descent. Jospeh:"Please try to follow along-" Is this how you argue/debate?Acipenser
January 4, 2010
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Acipenser:
Many other creatures also have gills so I don’t think we can use gills as a single indicator/characteristic of what makes a fish a fish.
All fish have gills. I never said anything abouyt a "single indicator". As for cold-bloodedness- nice of you to ignore my references. Is that how you "argue" too? Ignore what your opponent posts and trudge on anyway?
The embryos of mice, whales, and fish (as well as all vertebrate embryos)possess pharyngeal pouches a trait no other group of animals share.
So what?
I thought you mentioned earlier that you didn’t want to discuss taxononmy so I wonder what the change in heart was to motivate you to return to the issue of nested hierarchies.
Please try to follow along- Zachriel is saying that descent with modification- ie Common Descent- leads to a nested hierarchy. That is the pattern of nested hierarchy is evidence for Common Descent. Taxonomy is based on defined characteristics. The observed nested hierarchy is based on characteristics. Descent is not a characteristic. Neither is "who's your daddy?".Joseph
January 4, 2010
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Joseph:"As far as I can tell gills are a defining characteristic of a fish." Many other creatures also have gills so I don't think we can use gills as a single indicator/characteristic of what makes a fish a fish. Likewise given the number of fish that are endothermic cold-bloodedness is also a poor defining characteristic for determining what makes a fish a fish. Tunas and Lamnid sharks are well equipped to regulate their internal body temperature to a near constant temperature that is much higher than the environment in which they live. Perhaps one of the best examples is the salmon shark which must keep it's internal body temperature much higher than the environment to prevent muscle damage and promote adequate muscle contractability for movement. Endothermy does not equal cold-bloodedness. The embryos of mice, whales, and fish (as well as all vertebrate embryos)possess pharyngeal pouches a trait no other group of animals share. I thought you mentioned earlier that you didn't want to discuss taxononmy so I wonder what the change in heart was to motivate you to return to the issue of nested hierarchies.Acipenser
January 4, 2010
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Something more easily understandable ;) Warm-blooded fish?Joseph
January 4, 2010
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But anyway Acipenser are you with Zachriel in saying that descent with modification leads to a nested hierarchy? The point being is that Zachriel has said time and again that nested hierarchy is evidence for Common Descent even though it has been explained to him in detail why this is not the case.Joseph
January 4, 2010
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Acipenser:
I’m not sure what you are getting at since fish with lungs also have rudimentary gills to varying degrees.
As far as I can tell gills are a defining characteristic of a fish. If you have data to the contrary please present it. (Mice and whales do not have gills- ever) Temperature control in cold-blooded animals:
Scientific understanding of thermal regulation regimes has advanced greatly since the original distinction was made between warm- and cold-blooded animals, and the issue has been studied much more extensively. Many cold-blooded animals use behavioral means to adjust their internal temperatures: lizards and snakes bask in the sun in the early morning and late evening, and seek shelter around noon. many species of bees and moths flap their wings vigorously to raise the temperature of their flight muscles before taking off. bees in large hives will cool the hive in hot periods by going to its entrances and using their wings as fans to draw cooling air through the hive. They will warm the hive in cool periods by gathering in the middle and shivering to produce heat. termite mounds are usually oriented in a north-south direction so that they absorb as much heat as possible around dawn and dusk and minimise heat absorption around noon. Some other cold-blooded creatures use internal mechanisms to maintain body temperatures significantly above the ambient level: Tuna and Swordfish. Fish have long been thought to be cold blooded. Tuna and swordfish dive deep into the ocean where the water is very cold. Swordfish are able to raise the temperature of their brains and eyes, which allows faster eye movements when hunting. Tuna are able to warm their entire bodies through a heat exchange mechanism called the rete mirabile, which helps keep heat inside the body, and minimizes the loss of heat through the gills. They also have their swimming muscles near the center of their bodies instead of near the surface, which minimises heat loss. "Warm-blooded" sharks (e.g. mako and white sharks), to minimize heat loss through their gills, pass their blood through rete mirabile heat exchangers before it enters into the gills and after it exits from them: Veins are right next to arteries and thus extract heat from the arteries and carry it back into the body. Large sea turtles exhibit inertial homeothermy (Gigantothermy) - their low ratio of surface area to volume minimises heat loss.
Joseph
January 4, 2010
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