now tell me, how do "primitive animals" develop a faith based healing system such as the placebo effect?
how do you even know primitive animals HAD such a trait?
honestly?
i'm in frikken limbo here.
You are using the past tense. There are more primitive forms in existence today than modern forms. The study of living primitive forms, such as comparative anatomy and genome research, reveals that the slow accumulation of change--as it applies to the evolution of cells, tissues and organs--can be observed over the past 700 million years or more, simply by studying living creatures. The fossil record just helps confirm which forms came first - the principle of succession that Darwin speaks of. This is a huge body of scientific evidence that Creationists ignore. They want to focus on the gross body plan and argue that it completely defines evolution (a few have tried and failed to argue against the evolution of an organ -- such as an eye). But without ignoring the facts of nature, we see over and over again that even tissues, organs and systems have their own evolutionary trajectories, independent of the stages of change in gross features. And all of that can be confirmed by enrolling in a class in biology. That's why the teaching of biology is targeted by Creationists. Actual knowledge is a threat to their agenda.
As to the question of the underlying causes for brain activity, which I think is the intent of what you asked, I was beginning to tell you that there are two functions that dovetail - synapse and endocrine. Synaptic activity is recognized as electrical but that's only half true. The synaptic pulse is a phenomenon of transmission along the axon (strand) of a nerve. But the synapse itself, which can lead to the pulse transmission, is a chemical message. It's less commonly known that the brain sends chemical messages as well, directly to the various organs that it's controlling. Therefore all brain function can be reduced to chemical signaling. Since there is ample evidence of signaling inside cells and among groups of cells we can learn a lot about its evolution by studying microbiology and biochemistry. Shown below is an example of evolution as it applies to the origin of brain signaling. On the left is a living primitive cell which has evolved a flagellum (tail) for motility. In what appears to be the perfect example of what jan ardena has been asking for, with out any discernible change to the gross appearance of the cell, but as a change to its DNA, the cell acquires a colonial behavior. It's not just behavior, but physical and functional changes that give this evolutionary step a critical place in the dawn of first true animals. Individual cells will thus specialize - divide work into specific tasks. Something else happens. A hierarchical layer is built. Now it's the success of the colony that drives its evolution. The pressures are different. But all of that pressure gets transposed back to the DNA of the cell. The cell now figures into Darwin's theory as a building block, not as an individual within a species. The colony operates as the individual subject to selection. This is a topic that's barely been touched on here which is why I mention it.
As for the evolution of brain activity, here you have it, tracing it to its most primitive form. These cells are communicating, by sending chemical messages.
Again, this is just Biology 101. Any Creationist can take the class and cure their denial. On the left, a single collar cell, middle: same cell, adapted for colonial form; right: chamber of a sponge, with collar cells lining the wall, heads attached to the matrix and tails into the water. Incidentally, animal digestive tracts incorporate a homologue of the system seen in sponges. I'm referring to the microvilli of the mouth, throat, intestines etc. Here is a section of tissue. The heads are buried in the connective tissue and the tails - now called villi, with the broad feather-like adaptations seen, extend outward. Chemical messaging is in full swing. For example, the cells are regulated as to whether or not to take up glucose -- upon reception of a message from the pancreas, delivered in the form of insulin.
leopold said:
on the other hand i've seen NOTHING that supports "things become alive and develop a consciousness".
billvon said:
I have an 18 month old who would disagree.
All of that from two gametes - two molecules, housed in the most primitive of living structures - that of the very early Eukaryotes themselves. Using jan's criteria, look at the minor difference in the collar cell above and spermatazoa. The human ovum can be compared to the cyst cells of algae. In terms of evolution, we are a network of the most primitive of biological structures - single cells. But if not for the perfect code that produces the perfect child through the most elaborate ways of unpacking higher order structures: embryonic development. Then this: living, breathing, with little more than the suck reflex in terms of awareness. That and sense of gastric pain, a startle reflex, and some vague perception of light, sound, and the warmth of the mother.
No, I'm not talking about billvon's child. I'm talking about a kitten, an infant chimp, or a newborn mouse. You may find enormous physical differences in their gross characteristics, but in this regard, the state of awareness at birth, there is very nearly no difference at all. Each newborn of a species merely has the potential for growing that consciousness you speak of. All of that from two molecules. Life from non-life, in the strictest application of biochemistry. "Abiogenesis
in utero." Does it really matter that the sperm and egg cells were alive themselves? At its core every fertilization is a mere chemical reaction. Therefore all awareness is at its base a complex of chemical reactions. The rest, the part that drives a belief in an external source of consciousness, is negated by this. Otherwise we would have a memory that begins at the moment of fertilization, not the fuzzy dawning of awareness that happens the way it does. Similarly, if we say all cells are aware, then we would presumably have to "be in touch with" every cell in our bodies. It just doesn't fly. There is no need to invent explanations when there are more explanations available for study and test than any one person can hope to accomplish if they spent their whole life trying to. This is why I asked you, leopold, if you're sure you are not in denial. Your own defense mechanism will bias your answer. But have you even considered the abundance of explanations available to you, or are you avoiding them? That avoidance is the killer. That's the reason for asking yourself if you find it unpleasant to read the explanations for human origins, whether it's one I have given, or anyone else here, or any of the ones you commonly encounter doing a search.
aqueous mentioned this earlier in the thread, i asked his opinion on where this "awareness" comes from.
We've seen different definitions of "awareness" here. Usually, in common speech, we mean something more specific: self-awareness.
This is evidently acquired though stimulation and learning. Before we can try to define consciousness, we have to define all of the underlying structures that grew into place as life evolved. We would hardly call the random collision of two molecules, resulting in the formation of a chemical bond, as "awareness". We would hardly call those chemicals "alive". But even as we speak, countless collisions are taking place in the form of fertilization. From those unaware, un-alive molecules, something very complex yet very predictable is going to happen. Awareness arises from DNA, from the traits carried by the genetic code, which guarantee a particular hierarchy of processes and interactions, layer upon layer, leading to the platform of consciousness, upon which the upper layers, such as self-awareness, are built. But I don't think any of this is a matter of opinion, especially once we subtract out any of the errors in understanding we may have about the facts and evidence of scientific discovery. After all life is extremely robust -- DNA is -- in arriving at a hierarchy of organisms which demonstrate the evolutionary phases of development of the hierarchy that takes us from fertilization to self-awareness.
i was wondering where this comes from [detection of a food particle], apparently the entire cell is needed.
We just had an excellent introduction into protists, and the way slime molds work. We have touched on the amoeba, which apparently engulfs particles randomly. Simpler organisms, such as the cells in the tissues of the human body, merely absorb nutrients through the cell wall. The primitive metazoans (clusters of cells) form a larger surface that increases the odds of encountering nutrients. The forms that followed them - Cnidarians (e.g., jellies), Porifera (sponges-3rd photo at top) and Planarians (flatworms) each demonstrate innovations on the idea of trapping food by cooperation of multiple cells. And they each give evidence of the evolution of traits essential to animals. Sponges produce collagen-the precursor to dermal tissue-as art of the binding matrix that holds the cells together. Cnidarians are the most primitive forms known to have nerves, but first just as a sensor to active the umbrella to close when it detects a particle. Planarians innovate on this, joining the nerves at ganglia, resulting in what is probably the first and most primitive version of a brain. Through study of all of these organisms, there is no question that each cell, tissue, organ and system in modern humans is built from the gradual accumulation of configurations that succeeded in ancestral forms.
