Intelligent Design

Music, Evolutionary Cheesecake And The Designer Brain

Spread the love

A Review Of Daniel Levitin’s This Is Your Brain On Music

ISBN: 978-0-452-28852-2

Physicist Emerson Pugh once quipped, “if the human brain were so simple that we could understand it, we would be so simple that we couldn’t” [1]. In his book This Is Your Brain On Music neuroscientist Daniel Levitin notes how the number of ways that brain neurons can connect is so vast that we will never fully comprehend all the thought processes that we are capable of.

In recent years, mapping techniques have revealed a lot about the functional regions of the brain. Wernicke’s area is responsible for language processing, the motor cortex for physical movement and frontal lobes for generating personalities. Both encephalography and MRI have given us key spatial-temporal data about brain function in these regions. But we also find that activities such as listening to music contravene such a simplistic compartmentalization.

In fact the perception of pitch, tempo, the emotions invoked by a piece of music and the lyrics of a song all use different parts of the brain albeit simultaneously. Levitin repeatedly emphasizes the multi-faceted aspects of the music ‘experience’ noting how a, “precision choreography of neurochemical release and uptake” leads to our appreciation of music [p.188]. The brain is thus a massively parallel device, capable of carrying out several different tasks at once.

While it is through a lifetime of exposure that our brains become used to the note scales and music styles of our culture, it is during childhood that we are most receptive to learning music rules and note sequences. The finding that children’s tastes in music are heavily influenced by the music heard during prenatal development, has forced a shift in the way we think about childhood memory.

We now know for example that the cerebellum has the capacity to recall with precision accuracy the rhythm of a music piece long after it has been heard while the brain stem and dorsal cochlear nucleus are able to distinguish between consonant (harmonious) and dissonant sounds. In fact our brains are able to group sounds without any conscious effort from ourselves.

We rarely have difficulty deconvoluting the sounds of instruments- a trumpet will always sound like a trumpet and a clarinet always a clarinet. Every instrument has its own characteristic ‘fingerprint’ of tone frequencies many of which can now be copied by electrical synthesizers. Indeed frequency modulation synthesis has allowed musicians to simulate instruments and incorporate their own unique sounds into their music.

Levitin’s work at Stanford University has brought to light our capacity to faithfully remember music pieces in their original pitch and tempo. In essence the brain can re-deploy (’re-member’) the same neurons that were used in the original perception of a music piece. The sound separation capabilities of the brain, which allow it to differentiate between concurrent sounds (say two different instruments), are nothing short of remarkable.

We are only just beginning to understand how it is that the brain registers the sound signals that cause our ear drums to wiggle at certain frequencies. Feature extraction is the process through which neural networks then ‘decompose’ the sound signal into information about pitch, timbre and loudness amongst other things. Through repeated exposure, our brains generate ’schemas’ of what sounds should go together, what letters will appear in a word and what different types of music will sound like.

Levitin does a fantastic job in explaining the universal patterns and regularities of musical construction revealing the common music elements that unite apparently disparate pieces of music such as those of Mozart and The Eagles, Prokoviev and Steve Wonder. The non-arbitrary frequency distances between notes are what identify any given piece of music.

Levitin makes his book that much more exciting by recounting many of his own personal stories both as a musician and a neuroscientist. His work as a record producer with some of the biggest names in the business and some of the best-known artists of contemporary rock provides a unique flavor to his scientific discussion.

Nevertheless his conversations on evolutionary biology and its relevance to brain evolution with the greats of molecular genetics, notably Francis Crick and James Watson, are somewhat of a disappointment. Indeed in the last chapter Levitin develops the idea that music has served as a ‘vehicle’ for social bonding and cohesion citing the tendency of people to identify with others with similar music tastes as supportive evidence. He is quick to dismiss psychologist Steve Pinker’s assertion that music was nothing more than ‘evolutionary cheesecake’ that in humans rode on the back of the more critical adaptation of language.

Rather, Levitin sees music and musical appreciation as an adaptation in itself that may have allowed sexual partners to charm each other through their courtship displays (an extension of Darwin’s theory of sexual selection). He cites the highly social and musical tendencies of Williams Syndrome patients and the musical and social difficulties of autistic children as clear evidence of an evolutionary connection between music and social integration. But what of the complexity that Pugh so eloquently drew our attention to so many years ago?

Naturalist Jane Goodall expressed her views on evolution when she wrote of, “a series of vanished brains, each more complex than the one that came before it” [2]. And yet without the crucial evidence of the ‘how’- the mechanistic meat of evolutionary theory- the role of natural selection, particularly as relates to music appreciation, remains but a skeleton of speculation.

Literature Cited
1. Inside The Mind Of God- Images And Words Of Inner Space, Introduction By Sharon Begley, Edited By Michael Reagan, Templeton Foundation Press, New York, p.61
2. Jane Goodall (1999) Reason for Hope: A Spiritual Journey Warner Books Inc, New York, NY, p.126

31 Replies to “Music, Evolutionary Cheesecake And The Designer Brain

  1. 1
    Zachriel says:


    The average brain consists of one hundred billion (100,000,000,000) neurons. Suppose each neuron was one dollar and you stood on a street corner trying to give dollars away to people as they passed by as fast as you could hand them out- let’s say one dollar per second. If you did this twenty-four hours a day, 365 days each year without stopping, and if you had started on the day that Jesus was born, you would by the present day only have gone through about two thirds of your money.

    But if you started with one dollar in the morning and doubled it every hour, then you would have a hundred billion by the evening of the next day. Indeed, the human brain, with its trillions of cells, develops from a single cell.

    Robert Deyes: And yet for the origin of the human brain and the mind, the answer to that burgeoning question remains as elusive to science as the origin of life itself.

    The Theory of Common Descent provides strong evidence that the human brain, like everything else in biology, evolved by a process of descent with modification.

  2. 2
    Upright BiPed says:

    Nice post. Thanks!

    Right now I am listening to the 70 yr old, former South African exile, trumpeteer Hugh Masekela. The recording is about the Coal Train (Stimela) that runs from Malawi to Mozambique. About halfway through the song Masekela performs a trumpet solo that cannot be ignored.

    I know this silly anecdote has no meaning in this setting, but every time I hear that solo I cannot believe anyone could seriously suggest it is the result of unguided chemistry.

    http://www.filestube.com/3406e.....e9/go.html

    .

  3. 3
    tgpeeler says:

    Upright, it is only “apparently” beautiful and you are only “apparently” enjoying it. Haven’t you learned anything from ROb, Seversky, and others?? It’s just all one grand accident played out according to the laws of physics. Some people… 🙂 🙂

  4. 4
    Upright BiPed says:

    Yes Tom,

    I know. They have all made it abundantly clear they do not believe in the self. They deny themselves humanity and contradict themselves as they do it. When taken by hard evidence that their assumptions are misplaced, they question definitions and ignore context. When shown that their own methodologies, which they see as an enlightenment, are corrupted from the start, then they ignore history and cover their eyes.

    Still, there is Masekela. After he finishes his solo, he reverts from English and finishes the song in his native tongue. If you are succeptible to it, he can pull your heart through your chest even though you havent a clue what he is saying. The forebearance and pain of countless generations is captured by a man in his experience as a man – swept up and converted to crescendo.

    Of course, its all explained by the property of matter on the periodic table (plus a tortured and abused theory from the 1800’s).

    If that is their enlightenment from ignorance, then I thank God I am smart enough to remain ignorant to it.

  5. 5
    HouseStreetRoom says:

    I very much enjoyed this. Thank you.

    UprightBiped, I share your astonishment concerning the belief that man’s ability to create art is all the result of unguided chemistry. In my mind, music (art in general) is the single greatest refutation – from human experience -of the Darwinian paradigm.

    As I listen to the song you posted, Upright, I have shivers running through my body. Fantastic trumpet solo.

  6. 6
    Upright BiPed says:

    Hello HouseStreetRoom,

    Thanks for the comment.

    (btw, I’ve had the same response)

  7. 7
    jerry says:

    People tend to forget when they start discussing evolutionary processes that drive human beings such as the processing of music, altruism, development of religious ideas, etc. that all of these had to develop amongst a population of individuals that roamed the savannah or plains of central Africa in small packs over 60,000 years ago.

    Because once they left Africa this species spread to the farthest parts of the world and then there was little gene flow between the tens of thousands of sub populations from then on. So what is in the human today was there 60,000 years ago. Then ask how all these supposed sophisticated capabilities evolved in these primitive hunter gather packs.

    It is all BS as somehow humans were wired for these capabilities from the get go even when they were bopping around the grasslands chasing wildebeest or picking berries.

  8. 8
    Mung says:

    The Theory of Common Descent provides strong evidence that the human brain, like everything else in biology, evolved by a process of descent with modification.

    But we know this is false.

    Indeed, the human brain, with its trillions of cells, develops from a single cell.

    And I suppose that the process of multiplication of brain cells comes to a stop because no more brain can fit in the skull.

  9. 9
    tgpeeler says:

    Z @ 1

    “The Theory of Common Descent provides strong evidence that the human brain, like everything else in biology, evolved by a process of descent with modification.”

    THIS IS THE PROBLEM in a nutshell. The “theory” of common descent is NOT EVIDENCE, it’s an alleged explanation OF EVIDENCE. You say, in effect, that your explanation is evidence of your explanation. That is such a fundamental philosophical and logical mistake that it almost defies description. Evolution is proof of evolution. Nice job, Z.

  10. 10
    Zachriel says:

    tgpeeler: You say, in effect, that your explanation is evidence of your explanation.

    Not at all. The evidence for Common Descent is independently found in the nested hierarchy, including geological succession.

    tgpeeler: That is such a fundamental philosophical and logical mistake that it almost defies description.

    Like all scientific theories, the Theory of Common Descent is a collection of related claims that entail specific empirical predictions. Citing a well-established scientific theory does not constitute a “logical mistake,” though it is perfectly reasonable to ask for support.

    In any case, the evidence for evolutionary mechanisms has to be seen in the light of Common Descent. Before discussing the details of this or that transition, you should be comfortable with the evidence for the broad pattern of evolutionary divergence.

  11. 11
    PaulN says:

    Mung @8,

    And I suppose that the process of multiplication of brain cells comes to a stop because no more brain can fit in the skull.

    Your logical input always seems to come from a fresh perspective, and that’s what I’ve liked about you since you started posting here.

    The questions that surface from your astute reasoning consequently provide for some very cogent counterpoints to Darwinian claims.

    In this particular example you make a great point highlighting where the deliberate stopping point in the development of the brain would have to be preprogrammed, as there are no physical/chemical properties inherent within its building blocks to define such behavior. If you applied this reasoning on a broader scale, then the counterpoint becomes even more salient.

    What, in the world’s first hypothetical multicellular structures, would have prevented them from multiplying and growing into masses of cancer-like organic material? What prevented this from happening with the first skin, muscle, bone, and nerve cells for organisms that weren’t yet fully developed? In a trial and error system, one would almost expect to see unorganized asymmetrical masses of tissue, bones, and nerves before anything coherent began to take form in evolutionary history- especially leading up to the cambrian explosion. Who’s to say that Darwinian assumptions wouldn’t have led to just one giant mass of randomly assorted organic material as opposed to many different individual organisms? Natural selection would have been necessarily limited to selection at the cellular level at this point in time, meaning that there’s no need for diverse individual organisms to have ever existed, but rather just a big blob of successfully replicating cells.

    Thanks for sharing your reasoning =)

  12. 12
    PaulN says:

    Zach @10,

    tgpeeler: You say, in effect, that your explanation is evidence of your explanation.

    Zachriel: Not at all. The evidence for Common Descent is independently found in the nested hierarchy, including geological succession.

    Care to provide the plethora of universal examples required to verify this grand claim?

    Zachriel: Before discussing the details of this or that transition, you should be comfortable with the evidence for the broad pattern of evolutionary divergence.

    This is exactly the flaw the tgpeeler was trying to illuminate. You have to assume the concept of evolution as truth in order to explain evolutionary divergence. You cannot use a conceptual explanation as evidence for the reality of a concept.

  13. 13
    Zachriel says:

    Zachriel: The evidence for Common Descent is independently found in the nested hierarchy, including geological succession.

    PaulN: Care to provide the plethora of universal examples required to verify this grand claim?

    No single organism can be a “universal example” of a nested hierarchy, which refers to the pattern that results from parsimonious classification of numbers of organisms and structures.

    PaulN: You have to assume the concept of evolution as truth in order to explain evolutionary divergence.

    The nested hierarchy pattern is directly observed.

  14. 14
    PaulN says:

    Zach,

    No single organism can be a “universal example” of a nested hierarchy

    Right, which means a universal example of nested hierarchy would necessarily require a grouping of species, parent species, and their predecessor’s transitional forms. In other words an example that displays the concept of common descent universally. This could also be explained alongside said geological sequences. You projecting a limitation to the context of terms used in my request does not invalidate the request, but rather provides a means to avoid answering it.

    The nested hierarchy pattern is directly observed.

    Mendelian genetics can just as easily explain nested hierarchies based on empirical science without needing to extend claims that extrapolate beyond species boundaries.

  15. 15
    PaulN says:

    (Of course the hierarchies of inheritance that are empirically observed in Mendelian genetics are largely counterintuitive to Darwinian evolution and the claims of common descent)

  16. 16
    Zachriel says:

    PaulN: Right, which means a universal example of nested hierarchy would necessarily require a grouping of species, parent species, and their predecessor’s transitional forms.

    The nested taxonomic hierarchy exists regardless of any theory of ancestry, nor is it an observational artifact as it can be used to make empirical predictions. It’s an observed pattern. Let’s be sure we’re clear on that point before proceeding.

  17. 17
    Nakashima says:

    Mr PaulN,

    What, in the world’s first hypothetical multicellular structures, would have prevented them from multiplying and growing into masses of cancer-like organic material?

    There are simple physical limits that can stop growth. The cube-square law is one such. As a mass of cells grows, the inner ones are starved by the difficulty of nutrients diffusing into the inner parts of the mass. Controlling growth then becomes a selectable trait, since an animal that slows or stops may have better reproductive success than an animal with unlimited growth.

    Multicellularity also appears as the growth of films and sheets, so thinking 3D blob might not be the right analogy. Look at stromatolites growing layer by layer.

  18. 18
    PaulN says:

    Nakashima,

    As a mass of cells grows, the inner ones are starved by the difficulty of nutrients diffusing into the inner parts of the mass.

    Fair enough.

    Controlling growth then becomes a selectable trait, since an animal that slows or stops may have better reproductive success than an animal with unlimited growth.

    I disagree with this however, mostly because we’re considering selection at the cellular level- meaning as long as the individual cell can continue to reproduce then the mass of cells that it becomes a part of will continue to prosper, so reproduction of an animal can’t even be considered yet because I’ve been referring to a point in time that hypothetically predates animals.

    So there’s still a lot of explaining to do as far as how these cells diverge into tissue, muscle, bone, and nerve cells, and how they’re all regulated to form a functional organism without any tragically flawed intermediates strewn about the fossil record, and also how they develop what shapes to form, the size of these shapes, maintaining that size in proportion to other shapes, and how they all come together as a functional whole, again without any tragically flawed precursory failures (that don’t have the ability to deliberately and meaningfully regulate all of these parameters) strewn about the fossil record.

  19. 19
    ScottAndrews says:

    This is exactly the type of multi-step advancement that random evolution fails to explain.
    If a single cell varies in some way – perhaps it can survive a slightly different temperature – then that variation can become dominant in response to environmental changes. It’s not news. That type of microevolution has been observed.
    But for a cell to have a variation which alters its properties or reproductive behavior in such a way that it improves the survival rate for nearby cells (of which it has no awareness) which in turn gives itself a selective advantage – that sounds a bit like random chance emulating calculated reason. There’s no evidence that such things do happen or have happened, ever.
    Yes, our cells do collaborate to form structures and organisms. But there’s no evidence that such careful, orchestrated coordination did our could occur through random variations and selection.

  20. 20
    Zachriel says:

    PaulN: we’re considering selection at the cellular level- meaning as long as the individual cell can continue to reproduce then the mass of cells that it becomes a part of will continue to prosper,

    The original evolution of multicellularity occurred in very ancient times and left scant evidence.

    A Gap! Quick!! Get the Metaphysical Caulk!

    The difficult question is not cell differentiation, but the origin of cooperation. (Cell differentiation follows from cooperation.) Extant organisms (e.g. cooperating bacteria) reveal some of the details.

    Consider a simple example, the difference between rate and yield in the use of a locally limited resource. It behooves the individual to use the resource as quickly as possible so that others don’t get it before it’s gone, even if that usage is wasteful. However, if neighboring cells were to cooperate and use the resource more efficiently, then everyone benefits. The problem is someone cheats and the cheater wins by using up the resource and leaving more offspring.

    Now consider a brand new colony formed from a single cell that divides clonally. If this cell is a cooperator, then its offspring will probably be cooperators for several generations. They will prosper compared to colonies founded by cheaters. This will last until a cheater mutant comes along, then the cheaters will begin to overtake the colony. But what if the colony spawns before then, starting a new colony?

    Those colonies that spawn mostly cooperators will outcompete those that spawn mostly cheaters. The selective pressure would be to grow only so large, then spawn. The purification that results from founding a colony from a single cell allows the cooperative behavior to be transmitted and selected, and begins the process of a colony becoming an evolutionary individual.

    ScottAndrews: But for a cell to have a variation which alters its properties or reproductive behavior in such a way that it improves the survival rate for nearby cells (of which it has no awareness) which in turn gives itself a selective advantage – that sounds a bit like random chance emulating calculated reason.

    Even relatively simple cells, such as bacteria, communicate with their neighbors.

  21. 21
    ScottAndrews says:

    Even relatively simple cells, such as bacteria, communicate with their neighbors.

    They certainly do. And, as with the cells within a larger organism, there is no scientific explanation of how they learned to cooperate with one another to achieve the foresighted goal of their own survival without any awareness of their own existence, that of the other cells, or the whole they would help form to foster its collective survival.

    Darwinism’s explanations invariably boil down to something like this:

    However, if neighboring cells were to cooperate and use the resource more efficiently, then everyone benefits.

    No specifics, no mechanisms. Gloss over why and how cells began to cooperate. Just have faith in the magical power of nature to endow living things with whatever abilities they need to survive, play music, or do whatever else we observe them doing.

    I wouldn’t be so critical of your personal beliefs if you didn’t keep imagining and arguing that they were science.

  22. 22
    Zachriel says:

    ScottAndrews: Darwinism’s explanations invariably boil down to something like this:

    However, if neighboring cells were to cooperate and use the resource more efficiently, then everyone benefits.

    We can point to all sorts of examples of evolution in more modern times, but PaulN was concerned with the problem of selection at the cell level undermining group selection that could lead to the evolution of a cohesive cell group. Indeed, it’s a significant question.

    ScottAndrews: No specifics, no mechanisms.

    Let’s look at your previous statement.

    ScottAndrews: If a single cell varies in some way – perhaps it can survive a slightly different temperature – then that variation can become dominant in response to environmental changes. It’s not news. That type of microevolution has been observed.

    Those microevolutionary forces are exactly what are being investigated and proposed, that is, differential reproduction, selection and purification. The original transitions are very ancient (multicellularity arose more than once), but there are intermediate examples in extant nature; in particular, ATP rate and yield in bacterial microfilms. Modeling of microevolutionary forces can also help determine whether these mechanisms are sufficient to overcome the obstacle that PaulN pointed out.

  23. 23
    ScottAndrews says:

    It actually sounds like common ground to me. Changes have been observed in living things. Common descent seems plausible and fits the evidence in many cases.
    And research is ongoing to determine whether any non-intelligent mechanisms could be responsible for such changes (or for the organisms being changed.) That’s reasonable.
    I’ll do my very best to put aside my prejudices should any evidence to that effect ever be revealed.

  24. 24
    Mung says:

    Your logical input always seems to come from a fresh perspective, and that’s what I’ve liked about you since you started posting here.

    Thanks for sharing your reasoning =)

    Ok, I admit it, I’m susceptible to flattery, lol. But thank you.

    Have you noticed that so far you are the only one who thought my comment worthy of a response?

    And here I was, thinking that it was actually relevant and important.

    Zachriel:

    Indeed, the human brain, with its trillions of cells, develops from a single cell.

    Brains start from a single cell.

    Whoop dee doo!

    So does everything else in the human anatomy.

    Why does cell division ever stop, and why, specifically in the case of the brain?

    Is it because any more cells would become deleterious?

    In the case of the brain, is it because there is no more room in the skull? Or is there some other reason that the “brain cells” stop multiplying?

  25. 25
    Zachriel says:

    Mung: Why does cell division ever stop …

    A primary mechanism is contact inhibition. This is important in cell culture technology.

  26. 26
    PaulN says:

    Zach,

    A primary mechanism is contact inhibition.

    So you’ve identified the term used to explain this phenomena. But you’ve still ultimately failed to get the point of the question asked by Mung. What you have not done is explain how such a marvel has evidentially arisen from Darwinian causes or even fits with the theory.

    Theoretically, even with contact inhibition in place, how does it just happen to unfold to create a fully functioning complex organism? What determines when contact inhibition takes place and to what extent? How if at all, does this fit into a Darwinian scenario if the information for the limits of cell growth would have to be present ahead of time, especially when you consider how precisely every specific structure in a complex organism must fit together, interact with one another, and cooperate? The observation of contact inhibition in my opinion serves to be ultimately counter-intuitive to Darwinian claims, as the process of contact inhibition is necessarily guided and unfolds in a purposeful, precise, and specific manner.

    On top of this, if you even consider the implications this has on the hypothetical development of the first complex organism/animal, then it doesn’t take long to realize that contact inhibition would be useless if it weren’t defined ahead of time by pre-existing information. In other words you could still just as easily get a multitude of organic atrocities if there are no specific parameters in place to define exactly how contact inhibition is carried out. There is nothing in Darwinian claims that necessitates the creation of a meaningful structure from the process of contact inhibition. And given this, I’d still expect to see a plethora of terribly failed body plans in the fossil record before the first successful body plans appeared. I’d expect to see amorphous, asymmetrical, incoherent collections of biomass before anything resembling what we see in the cambrian explosion came to be. Either that or I would expect for life to never have arisen at all, as contact inhibition can stop cell growth when just two cells meet one another. There’s obviously a smart mechanism behind how it selectively limits cell growth to facilitate proper function at higher levels, and dare we even conceive the hypothetical outcomes before contact inhibition was in place, and every multicellular arrangement were to grow in a cancerous fashion?

    This is important in cell culture technology.

    Not only is it important, but it’s logically necessary for any complex organism to exist. Also I hope I’m not the only one who sees the irony in your classifying this as technology.

  27. 27
    PaulN says:

    Also I apologize ahead of time if you were referring to man-made cell technology as opposed to the biological technology inherent within the cell cultures themselves. I just caught myself on the two possible ways that statement could be construed.

  28. 28
    Zachriel says:

    PaulN: So you’ve identified the term used to explain this phenomena.

    It’s a mechanism, not just the phenomena. There could be other mechanisms involved, such as a programmed number of replications.

    PaulN: But you’ve still ultimately failed to get the point of the question asked by Mung.

    As Mung suggested “is it because there is no more room in the skull,” that would indicate he was interested in mechanism.

    PaulN: What you have not done is explain how such a marvel has evidentially arisen from Darwinian causes or even fits with the theory.

    Much of your question involves the evolution of metazoan architecture which is very ancient. Differentiation of somatic and germ cells is probably a critical change. There are some clues in Porifera.

    Müller, How was metazoan threshold crossed? The hypothetical Urmetazoa, Comparative Biochemistry and Physiology 2000.

    Koziol, Sponges (Porifera) model systems to study the shift from immortal to senescent somatic cells: the telomerase activity in somatic cells, Mechanisms of Ageing and Development 1998.

    Müller, Bauplan of Urmetazoa: Basis for Genetic Complexity of Metazoa, International Review of Cytology 2004.

  29. 29
    PaulN says:

    Zach,

    It’s a mechanism, not just the phenomena. There could be other mechanisms involved, such as a programmed number of replications.

    “Contact Inhibition” is the broad term used to describe an observed event, in this case the observed stop-growth of cells upon making physical contact with one another. The mechanisms behind contact inhibition are still not fully understood, and in fact may not have anything to do with contact at all. In concordance to what I emphasized earlier, more than just physical contact is necessarily required for this event to occur in any meaningful manner, which would render this to be a phenomena. for the development of complex organims and especially in the case of the human brain.

    Phenomenon:
    1. an observable fact or event
    2. a fact or event of scientific interest susceptible to scientific description and explanation.
    3.an exceptional, unusual, or abnormal person, thing, or occurrence.

    Take your pick.

    According to a nature review-

    Now, the term contact inhibition of cell movement is used quite broadly107, 108. By contrast, it is not clear whether contact inhibition of cell proliferation depends on cell contact; in fact, there is compelling evidence that it does not109, 110. Therefore, downregulation of mitosis in confluent cells is also called ‘density-dependent inhibition of mitosis’ (Ref. 111). The contact inhibition of cell movement and proliferation is crucially important in organogenesis as well as in wound healing. Although there are several reports that cell adhesion molecules are involved in contact inhibition10, 94, 95, the mechanism for this is not fully understood.

    http://www.nature.com/nrm/jour.....7_BX1.html

    You continue-

    As Mung suggested “is it because there is no more room in the skull,” that would indicate he was interested in mechanism.

    Which you have still ultimately failed to provide to any acceptable scientific standard of explanation for reasons that I’ve just explained. It would be like asking “What makes a wheel turn?” And someone answering “Motion.”

    Also, would you mind providing me with access to the articles that you’ve cited? It would be nice to find out whether they have some rich explanatory content or just another set of excessively broad, excessively hypothetical and/or excessively counter-intuitive descriptions.

  30. 30
    PaulN says:

    Also, cellular signal transduction seems to play a large role as a mechanism in contact inhibition.

    You can find a signal transduction pathway diagram here:

    http://en.wikipedia.org/wiki/F.....ion_v1.png

    Wikipedia article here:
    http://en.wikipedia.org/wiki/Signal_transduction

    From what I’ve seen so far, there are a number of different complex mechanisms that contribute to contact inhibition, none of which I’ve read about so far fit evidentially into the grand claims of clumsy Darwinian synthesis, but rather fit the incredible trademarks of super-intelligent engineering, as the extensive fossil record shows a collection of fully-developed and fully-functional body plans with little to no functional failures.

  31. 31
    Zachriel says:

    PaulN: “Contact Inhibition” is the broad term used to describe an observed event, in this case the observed stop-growth of cells upon making physical contact with one another.

    That’s correct. But it’s more information than just a restatement that cell division stops.

    PaulN: The mechanisms behind contact inhibition are still not fully understood, and in fact may not have anything to do with contact at all.

    That’s correct. It may sometimes be more closely correlated with cell density.

    PaulN: Which you have still ultimately failed to provide to any acceptable scientific standard of explanation for reasons that I’ve just explained.

    “No more room in the skull” is a directly parallel explanation to “contact inhibition.” Both would leave many important details unstated or unknown, but it is not the same as not providing an answer as you suggest. And it is something that can be directly observed and studied. However, your additional questions concerning the details of that process are certainly reasonable.

    PaulN: From what I’ve seen so far, there are a number of different complex mechanisms that contribute to contact inhibition, none of which I’ve read about so far fit evidentially into the grand claims of clumsy Darwinian synthesis, but rather fit the incredible trademarks of super-intelligent engineering, …

    Actually, it ‘looks’ like something that evolved. But how it ‘looks’ to you or someone else is not a valid scientific test, of course. There’s still a lot unknown about this ancient transition, but there’s also quite a bit of research on the evolution of signal transduction. For instance, prokaryotes are dominated by single component systems with both input and output domains on a single protein, which is the type of intermediary expected by an evolutionary process.

    PaulN: … as the extensive fossil record shows a collection of fully-developed and fully-functional body plans with little to no functional failures.

    Of course not. The Theory of Evolution would not posit functional failures persisting long enough to be likely to leave fossils. The process of creating such a large, complex structure would be through viable steps. We have reasonable scientific assurance of this because of Common Descent, the observation of evolutionary mechanisms, and the many other established cases of evolutionary transition.


    This review article should be available, albeit somewhat dated.

    Müller, The Origin of Metazoan Complexity: Porifera as Integrated Animals, Molecular Biology and Evolution 2003.
    http://icb.oxfordjournals.org/.....act/43/1/3

Leave a Reply