More Complex than Previously Thought-Part IV

Recent research that Darwinism has added yet another epicycle to the geocentric theory that is evolution.(1)

ScienceDaily (Jan. 27, 2009) — A new and comprehensive analysis confirms that the evolutionary relationships among animals are not as simple as previously thought. The traditional idea that animal evolution has followed a trajectory from simple to complex—from sponge to chordate—meets a dramatic exception in the metazoan tree of life.

New work suggests that the so-called “lower” metazoans (including Placozoa, corals, and jellyfish) evolved in parallel to “higher” animals (all other metazoans, from flatworms to chordates). It also appears that Placozoans—large amoeba-shaped, multi-cellular animals—have passed over sponges and other organisms as an animal that most closely mirrors the root of this tree of life.

“To make inferences about the origin of Bilaterians—animals with a bilateral symmetry, like humans—earlier studies suggested sponges, ctenophores (comb jellies), or a small, interesting group called Placozoa as the most basal or primitive animal,” says senior author Rob DeSalle, Curator at the Sackler Institute for Comparative Genomics at the American Museum of Natural History. “But our new analysis implies that the first major event in animal evolution split bilateral animals from all others, and our work firmly places Placozoa as the most primitive of the nonbilaterian animals.”

Then they go on to note that the nervous system must have had to evolve twice, because of where the supposed split in the evolutionary branch occurred.

The phylogeny drawn from the new analysis places Placozoans as basal within the Diptoblasta, a group of animals that includes sponges, comb jellies, jellyfish, corals, and anemones. This means that sponges and comb jellies, both previously considered candidates for the most basal animal, fall within the clade as more derived than Placozoans and as sister taxa to each other. Study results also identify a very deep division between the Diptoblasta and the Bilateria/Triploblasta: when looking at all animals, scientists now see that Placozoans and their relatives are in a separate lineage from all other metazoans (starfish, bivalves, anthropoids, crustaceans and chordates). This means that the nervous system, once thought to have arisen once, must have evolved twice from the DNA that coded for these complex systems (keeping in mind that while Placozoans and sponges do not have nervous systems, many of the taxa related to them do.)

Count me as one who is “shocked” by these findings.  The Darwinists now want us to believe that neurons and nervous systems evolved independently in two separate instances with nothing more than blind processes as their guide.

“Some people might initially be shocked to see that nerve cells in cnidarians and higher animals (Bilateria), the group of animals that includes humans, evolved independently,” says Schierwater. “But with this new phylogeny, we can take a closer look at the anatomy of these organisms—and we can see that their nervous systems are not all that similar at the morphological level after all.”

DeSalle agrees. “It is the underlying genetic tool kit that is similar amongst these basal animals. Placozoa have all of the tools in their genome to make a nervous system, but they just don’t do it.” (emphasis added)

So, these animals have all the tools available in their toolkit of a genome to make a nervous system, but they just don’t do it.  Score one for the “front-loaders.”  I’m a front-loader, but not of the common descent variety.  I believe that God may have designed mechanisms into the genome in order to allow for adaptation and change in response to environmental demands.

(1). New Tree of Life Divides all Lower Metazoans from Higher Animals

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13 Responses

  1. “…not as simple as previously thought.”

    The escape button for all their failed attempts! How convenient!!

  2. In calling this sort of discovery an “epicycle,” I think you’ve made a serious logical error — you’ve conflated the complexity of the phenomenon with the complexity of the explanation. The problem with epicycles is that they were cumbersome explanations — more precisely, they made astronomical calculations much more difficult to carry out. Whereas this sort of discovery shows that the world itself is more complex than previously thought — that’s very different. We can have simple theories of a complex world, and complex theories of a simple world.

  3. I agree DB. There is never or rarely a point of reflection on the general theory, because they know it is true by default.

  4. Carl, I disagree. Just earlier last year (March), these creatures were announced as clarifying the phylogenetic tree of common descent. They were considered to be near the bottom of the tree, and this was hailed as a great clarification of evolutionary history. Now, they say these organisms are on a completely separate branch and independently evolved a nervous system. Just like the eye is supposed to have evolved independently on at least 25 separate occasions. You may find Hunter’s analogy to geocentrism to be misapplied, but I think it fits well. You have a lot more faith in blind processes than I do, and you are deeply committed to the naturalistic perspective.

  5. […] I ask, “Why”? What do Darwinists have to fear from “‘the strengths and weaknesses’ of evolutionary theory” being […]

  6. […] I ask, “Why”? What do Darwinists have to fear from “‘the strengths and weaknesses’ of evolutionary theory” being […]

  7. Score one for the “front-loaders.”

    Looks to me like one person’s “front-loading” is another person’s exaptation. How it’s classified — as front-loading or as exaptation — depends on whether or not one regards the phenomenon on the basis of a (weakly) theistic world-view or not.

    (I say “weakly theistic” because intelligent design is compatible with polytheism and with deism as well as with monotheism — but it’s been argued, and I think correctly, that “maybe aliens did it” is not even a coherent point of view for an ID advocate to take. Regardless of theological commitments, ID is committed to the existence of at least one supernatural intelligent being.)

  8. Shrink, you wrote:

    Count me as one who is “shocked” by these findings. The Darwinists now want us to believe that neurons and nervous systems evolved independently in two separate instances with nothing more than blind processes as their guide.

    I’m not sure why you view the evolution of neurons and nervous systems as so difficult, given that:
    1) virtually all cells exploit voltage potentials across both cell and internal membranes; and

    2) that the neurons in mammalian brains primarily use the same proteins and mechanisms used in garden-variety fibroblasts for basic housekeeping functions.

    This co-option (not even requiring duplication) is prominent even in long-term potentiation (or LTP), the only robust molecular mechanism we have for explaining learning/memory. If you like analogies, reusing these proteins in this way is like sticking a ’66 VW Bug engine in your Lamborghini instead of designing a new one.

    So, these animals have all the tools available in their toolkit of a genome to make a nervous system, but they just don’t do it. Score one for the “front-loaders.” I’m a front-loader, but not of the common descent variety. I believe that God may have designed mechanisms into the genome in order to allow for adaptation and change in response to environmental demands.

    Then why, when you look within a single organism, would the same proteins (not merely related ones) play essential roles in both housekeeping and our most distinguishing feature as human beings–our incredible ability to learn? Why can we make great strides in understanding mechanisms by viewing the most important part of the neuron for LTP–the dendritic spine–as a modified fibroblast, the most undifferentiated cell type there is (with the possible exception of the one-cell embryo)?

  9. I’m not sure why you view the evolution of neurons and nervous systems as so difficult, given that:
    1) virtually all cells exploit voltage potentials across both cell and internal membranes; and

    2) that the neurons in mammalian brains primarily use the same proteins and mechanisms used in garden-variety fibroblasts for basic housekeeping functions.

    This co-option (not even requiring duplication) is prominent even in long-term potentiation (or LTP), the only robust molecular mechanism we have for explaining learning/memory. If you like analogies, reusing these proteins in this way is like sticking a ‘66 VW Bug engine in your Lamborghini instead of designing a new one.

    John, I think you are greatly oversimplifying the complexity of neurons and the differences between a neuron and other cells. And I think you provide a false analogy. What you are describing is a VW Bug changing it’s exterior on it’s own to be a Lamborghini (on two separate instances with no sharing of a model). Furthermore, action potentials, neurotransmitter release, information processing in networks, and so forth are hardly simple processes. Memory is also much more than LTP. You have to have sensation at a minimum before you will have memory in a living organism. I’m trying to take a look at the bigger picture here.

  10. I’m not sure what your point is Carl. Exaptation appears to be very different from what is described in the research that I cited.

    Personally, I agree with you to some extent on the theistic implications. To me, ID makes less sense with weaker theistic arguments, but I’m probably in the minority there.

  11. John helpfully points out that use of voltage potential across membranes are commonly found in cells, so it seems a good working hypothesis that the genes in question — those found in neurons but also in animals without nervous systems — could be used to build the proteins that regulate ion transport. (Emphasis on the seems: I’m speculating wildly here.) If this were so, why would it not be a case of exaptation?

    As for “the big picture”: the ‘big picture’ which I’m trying to get into focus is one based on principles of emergence and self-organization. In this picture — I would not call it a theory! — small changes at one level of organization can result in substantial changes at a different level of organization. Animals without nervous systems to animals with; from animals with small brains to animals with larger brains; etc.

    [Interestingly, one of the main theorists of self-organization, Stuart Kauffman, has interacted with Dembski on several occasions, e.g. see here and Dembski’s interesting and highly critical review of Kauffman’s book here. Kauffman also contributed his introduction from Investigations to Debating Design, ed. Dembski and Ruse.)

  12. Shrink:

    John, I think you are greatly oversimplifying the complexity of neurons …

    I assure you that I am not. I work on axonal transport and LTP. They are incredibly complicated, and I’m excited about our latest work that adds to the complexity of axonal transport by demonstrating something even more complicated.

    …and the differences between a neuron and other cells.

    Again, I am not denying the differences between neurons and other cells. What I’m pointing out is that either:

    1) A scandalously cheap designer designed the great complexity of neurons without bothering to use many new components; or

    2) Neurons evolved their great complexity using mostly the same proteins that other cell types use. Again, not merely related proteins, but the same ones.

    And I think you provide a false analogy. What you are describing is a VW Bug changing it’s exterior on it’s own to be a Lamborghini (on two separate instances with no sharing of a model).

    No, my analogy is that a fibroblast is a Bug, and a neuron is a Lamborghini. If, as an intelligent designer with a Bug already in front of me and the goal of building a Lamborghini, I’m not very intelligent if I simply reuse the VW motor, yet that’s what evolution must do (I work on “molecular motors,” btw). Evolution either uses the actual VW motor or an obvious modification of it.

    Furthermore, action potentials, neurotransmitter release, information processing in networks, and so forth are hardly simple processes.

    I would never claim that they are. I am simply pointing out that the same, not just related, proteins are used. For example, the same motor that functions in the endocytic recycling of transferrin and its receptor in fibroblasts (which is complex and maddeningly fuzzy itself) functions in the recycling of a glutamate receptor subunit that is required for LTP.

    Memory is also much more than LTP. You have to have sensation at a minimum before you will have memory in a living organism. I’m trying to take a look at the bigger picture here.

    I’m not claiming that LTP is all that is required for memory. I’m saying that LTP is the best mechanistic (regardless of design vs. MET) explanation of the foundation of memory as a relatively stable change in synaptic strength. Obviously sensation feeds into that.

  13. You really need to look at the complexity of neurons and nervous systems in a little more detail. You have combined analog and digital processing (digital with action potentials; either firing or not, and analog with neurotransmitters and the chemical events leading to the neuron firing). What you want folks to believe is that the same system evolved twice. Why would you end up with the same type of cell and system through a blind process? Why not a purely analog system?

    If you don’t think these are incredibly complex processes, then I challenge you to develop a computer simulation that can mimic all the processes in just a network of 1000 neurons. I’m not talking about a reductionistic simulation either. I’d like to see the full processes simulated. The fact is, that the complexity is such that we are only scratching the surface in understanding these processes. But you want people to believe that blind processes converged on the same highly complex solution more than once.

    John, as to your reference of component parts, nearly all cars have steel in them (from the clunkers to the race cars), and by the way of your analogy you could say that the race cars are not designed because they use such a heavy metal. It just doesn’t fly.

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