Sensory evolution

Are you responding to me? Or another post?

Are we talking about the beginning of the evolution of senses? Or just in humans?

If we are talking about the origins of sensory perception, then we have to go back to the stimulus-responce perception exhibited in microorganisms. This is microbiology. What are you after? Either way, we have to go back to the ancestorial origins of humans to our amphibian ancestors then to fish then to their sensory perceptions.

 

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If you are refering to my original post then I've assumed nothing. Pick any living thing you wish, what's the difference? Anyway.....

How would an early lifeform know when its touching another? Chemical reactions triggered development of receptors? Once we had one receptor did every other evolve from that original? You guys seem to be quite knowledgeable...can you help me out here?

 

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Maybe the original signal was a change in membrane potential? (???)

 

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Yes, in fact chemical reactions triggered the development of the evolution of life as a whole. But in regard to sensory perception, chemical reaction pathways and networks developed into sensory receptors that monitor both the internal and external environment of the organism. Internal perception probably evolved first so as to control and regulate the evolving metabolic pathways within.

Sensory receptors are specialized organs within the body that respond to internal inputs and codes and translate outside environmental impulses into nerve impulses that are transmitted through the central nervous system to your brain. Nerve impulses are electrical impulses but the organs and neurons that transmit them evolved from chemical pathway networks that evolved within the organism.

Chemicals and light images in the environment are interpreted by your senses. Similarly, pain does not exist in the environment: it is an interpretation of that external environment transmitted by pain receptors to you brain. The origin of all these sensory pathways are the metabolic chemical pathways and networks that evolved by the evolution of our interior metabolic network system throughout the course of the history of life on Earth.

 

What do you mean by chemical reaction pathway?

 

I'm not sure if this qualifies as an extra sense or not but would a sense of being be one? Is it just for the realm of humans or would every creature on Earth possess it? or must an organism develop sensory perception before gaining a sense of being? I think the latter. Although every creature must have some kind of built-in awareness of others to survive.

Sorry for the raw terminology for the next 2 paragraphs plus the lack of hard information.

On Sunday nite I had a chance to watch the science series Nova on public tv. It was a session that provided a catch-up on what's happening today. They showed a lab, I can't remember where, that manufactured DNA. They had the basic ingredients and just whipped it together. Place an order and they will give you any blueprint you want.

There was also another professor, again can't remember where, who with a bunch of other doctors are trying to make life from scratch. They went on to mention that it is very close to reality and very inexpensive. In an experiment they put some kind of chemicals together and the most amazing thing about it was how the chemicals automatically assemble into individual cell-like pseudo organisms complete with what appeared to be a membrane when viewed under a microscope, the only thing lacking was the spark of life. Has anybody seen that show and I was wondering just how accurate it was.

 

No, when you start talking about sense of being then your talking about self-awareness and that refers to consciousness in general. And consciousness includes your neural network system. Scientists have shown that if you start cutting some of the neural networks that lead to te cortex of the brain then you loose consciousness. I could look that study up if you're really interested in it.

Most, if not all, simple organisms have sensory receptors (even single-celled organisms like yeasts) but not a built-in awareness of others. Only higher level animals have that. In the case of yeasts, they're able to detect internal changes in what's called osmotic pressure (basically this means they can detect differences in water pressure that can pass through their cell membranes). However, as a side note, it is thought that our own basic nervous system, and the nervous system of animals so diverse as that between flies and mice, share so many common features, that these features must have been already present in a remote single common animal ancestor. Insects, arthropods, crabs, reptiles, birds, and mammals all have sensory receptors consisting of sensory neurons made up of nerve cells that convert stimuli from the organism's internal or external environment into electrical impulses.

In addition to the five commonly referred to basic senses in humans: sight, smell, touch, hearing taste. Other non-human senses are:

Electroception: detects electric fields, examples: some fish, sharks, rays the platypus

Magnetoception (or "magnetoreception"): detects fluctuations in magnetic fields, example: migratory birds, insects such as bees.

Magnetotactic detection: specifically determines their orientation relative to the Earth's magnetic field, example: some bacteria

Echolocation: determine orientation to other objects through interpretation of reflected sound (like sonar), examples: bats and dolphinsd Bats and dolphins.

Pressure detection: found in fish and some aquatic amphibians used primary for navigation, hunting, and schooling.

But in terms of the stimuli that are converted to electric impulses in the different types of sensory receptors, the following is a list of those stimuli receptors:

- Chemoreceptors respond to chemical signals
- Mechanoreceptors respond to touch or pressure
- Thermoreceptors respond to heat
- Photoreceptor cells respond to light
- Baroreceptor cells respond to pressure
- Osmoreceptor cells respond to the level of fluids (in the hypothalamus)
- Proprioreceptor cells respond to motion, position or balance

from "Wikipedia: The Free Encyclopedia"
http://en.wikipedia.org/wiki/Sensory_receptor

 

I have a hard time believing we are the only organism that has a sense of being. Is a sperm aware of an egg? Or an embryo of its mother? If the answer is no then I can safely assume that a human embryo is not aware of its sense of being. The sense of being must then come after birth or it may be after a certain moment in the womb. Not a true sense as far as senses go? but dependent on the true senses?

 

As I said, only in what we refer to as higher level animals, as compared to simple microorganisms have a sense of sense of being. A sperm is not "consciously" "self-aware" of an egg, but is genetically coded to penetrate it when released to do so. A sperm does not have a consciousness so it cannot be self-aware.

Right know I now that my dog has a consciousness and is self-aware that I better let him go out to pee, and that's why he's barking at the door while looking at me.

An embryo of it's mother? At some point in the development of an embryo inside its mother it develops a consciousness, but how could it be self-aware of its mother until it was outside of the womb to see her? Or to see where it came from? Some people - my brother included - claim they recall experiences from when they were inside the womb of their mother, but I don't see how they could be aware of their mother or the existence of other beings or life until they experience them outside the womb. At some point an embryo develops a consciousness, but a self-awareness of what?

 

Oh there's no doubt about that, dogs classified in the AKC system, like hound dogs, are classified because of their scent smelling abilities. Like I said, those big long snouts are not just hollow and empty. I just heard somewhere along the line that they could smell about 50,000 times as many scents as humans. Don't know. Could just be hearsay, but I'm sure it would be on the magnituide of at least a thousand or more. I haven't personaly read any studies on it though I should research it so as to post something more precise.

On the subject of eyesight, some people think that dogs are colorblind. That's nonsense but it is a fact that they see different shades and quality of colors than humans. I researched this on Cervidae species (Elk and deer) and found out that they are in fact colorblind to many colors. Ironically, the colors that they are most perceptive to distinguish are bright colors like bright red and orange: just the same colors that hunters are required to wear in the field so that other hunters can see them and don't shoot the hunters.

 

Sorry about all the questions but here are a few more.

Have we(humans) developed all the senses we're going to get or will there be more? Do you think there will come a time when certain senses become obsolete? If so then which will be the first to go? Maybe we've lost some already.

When we first become infected with a virus we don't usually know it but our body starts fighting it right away. Is the triggering of anti-bodies the result of a sense and if so does it have a name?

 

Invert_Nexus or Spurious Monkey may be able to contribute more than I to this question as it all depends on our evolution and Natural Selection. If they do not also reply, then you might also want to post the same question on the "Evolution: Please Explain" forum.

We as humans now have five main senses (refer to my post above about other sense receptors in other animals). The answer to the question depends on what we expect - or what will - the environment be in the future. One can only speculate. For example, perhaps the Earth will become so polluted with garbage that all the obnoxious smells will lead to our ignoring them and our eventual loss of the sense of smell: unlikely. I would argue to the contrary, that since we as humans now control our own evolution through artificial selection, this would not apply. Here I am opening myself up to a great deal of possible debate.

If our environment evolves where other stimuli become more prevelant and pervasive than we have right now, then I would think that through natural selection we would evolve senses - like those that already exist in other animals - to detect them.

Our immune system that develops anti-bodies to attack viruses is triggered by chemical and enzyme responses within the cell when these viruses penetrate cell membrane walls and detect it as being a foreign invader. I would think that this responce would be due to chemoreceptors that respond to chemical signals. Don't know.

 

All mammals basically have the same set of senses. Some are just better developed than others depending in the animal.

 

Please do. I would be interested, but I'd bet "dollars to donnuts" that you never give that reference to me - Why?

(1) It is impossible to know that anyone but your self is conscious - Called "the other minds" problem in philosophy. Everyone but you may only have behavior that is similar to yours, but they could be totally unconscious, usually referred to as the "zombie alternative" to consciousness in others.

(2) Even if one considers only the highest non-humans, say the great Apes and monkeys, they is little reason to say they are conscious (other than a presumption that they might be). Only a few types of apes passed the "self awareness test" (and as far as I know there is only one that has been applied to annimals):
While sleeping a small dot was painted on the forehead. A mirror had been available for weeks just outside the cage. When the animal happened to look in the mirror, only a few of of the great apes (none of the many different types of monkies tested) gave any indication that they knew that the image is their own - probably monkeys do not even have a concept of "me") by touching the spot on their forehead, etc. Lesser animals surely do not know they exist by the mirror test. A single bird in a cage is much less nervious if he has a friend in the mirror. Dogs will often show hostility to their own mirror image. (Have you not heard the moral about the dog looking in still water losing the bone in his mouth to bark at his image etc. -it is likely based on an observation of this actually happening.)

(3) No scientist has ever pubished a paper as you describe. If he had destroyed the consciousness of a human (and only in humans can we reasonably assume that consciousness is really a reasonable assumption) he would now be in jail.

Valich you sometimes have something reasonable to say (generally I think text copied from some where else) so my "ignore list" is still blank, but as most of very frequent your posts seem pointless and often when original are things you simply invented (like this obviously false assertion) your posts mainly get in the way, so I will use your reply to this one to see if I should populate my ignore list for the first time. If you can give a published journal reference, I will "eat crow" but again for the reasons stated above, think you are just dreaming things up to post.

 

>> Only a few types of apes passed the "self awareness test" <<

...and then there even is the possibility that they may be THAT conscious that they deliberately spoil those 'tests' and perhaps even lough at those fellow human scientists

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but seriously... may I remind here that just until recently even humans of certain races have been declared as being non-conscious... some even as not being human at all... and that all accompanied by lengthy scientific research and everything...

Explaining consciousness still is little more than a very subjective interpretation. And often terribly interwoven with ideology and other political and/or economical reasons.

 

That's a rude hypocritical reply. Hypocritical because such a reply as yours ironically only serves to "get in the way" for those of us who truly want to learn something, rather than just playing cyber-games on a sciforum. I came across the article that stated what I said above and I relayed the info. What a demeaning comment to make that you put people on your "ignore list." Judging from your arrogant, impolite, and belligerently immature "challenging" attitude, tell me one good reason why I should not put YOU on MY ignore list? Though "I" unlike you do not keep one. Grow up and learn!

"Brain awareness doesn't come out of thin air. There is evidence aplenty that it critically depends on a set of neural activities. What is more, recent findings compellingly suggest that consciousness is a function of an identifiable neural architecture."
http://www.datadiwan.de/SciMedNet/library/articles/9803141712.htm

"consciousness is associated with macroscopic neuronal processes"
http://66.102.7.104/search?q=cache:..., cutting neural, loss of consciousness&hl=en

"Many patholigies of consciousness involve cases in which a neral damage has caused a loss of consciousness."

"The reticular formation is thought to modulate the activity of many higher-level neural structures, notably the neocortex; the nucleus reticularis is believed to control thalamic 'gatelets' that can open or close sensory tracts on their way to the cortex. Lesions of either structure result in a loss of consciousness. (Baars 1993:288)"
http://66.102.7.104/search?q=cache:..., cutting neural, loss of consciousness&hl=en

"In the comatose state, one finds no evidence of awareness of self or environment,.... derived from damage, including large cerebral and BRAINSTEM ischemic stroke [also BRAINSTEM LESIONS OR CUTTING OF THE BRAINSTEM NEURAL NETWORK]....

Persistent Vegetative State....varying degrees of destruction/degeneration that affect bilaterally the cerebral cortex, the cerebral white matter, and sometimes...mesencephalic lesions that mostly reflect damage secondary to early compression of the brainstem....vegetative states may also result from focal injuries to the paramedian brainstem and thalamus (Castaigne et al., 1981; Facon et al., 1958; Kinney et al., 1994; Plum and Posner, 1966; Relkin et al., 1990).

The concept of brainstem arousal systems was introduced by the pioneering work of Morison and Dempsey (1942), Jasper and Droogleever–Fortuyn (1947), and Moruzzi and Magoun (1949)....Several studies have sought to determine how necessary or sufficient the individual brainstem nuclei are, including the serotoninergic (median raphe) and noradrenergic (locus ceruleus) groups, providing compelling evidence that any single group is indispensable (Dringenberg and Vanderwolf, 1997; Marrocco et al., 1994; Steraide et al., 1997)."
scource: "The Role of Arousal and “Gating” Systems in the Neurology of Impaired Consciousness," by Schiff, Nicholas D; Plum, Fred, "Journal of Clinical Neurophysiology," Vol.17(5), Sept 2000, pp 438-452.
http://gateway.ut.ovid.com/gw1/ovidweb.cgi

The brainstem is the "neural network" that connects the brain to the spinal chord. If you cut the brainstem, you cut a neural network that leads to a loss of consciousness.

Because I did not receive your reply until today, I do not remember the exact search terms that I used to find the original research article that I was referring to. However, if you prove yourself to be worthy enough, i.e., as a person with a "sincere desire to learn" without a condescending anti-productive demeanor, then I will gladly go out of my way - though I am extremely busy - to try and relocate the original article that I referred to about specifically cutting neural networks that go to the brain that lead to a loss of consciousness.

 

I don't know what you mean by the "self awareness test," but I do believe that many mammals are self-aware of themselves, and I also agree with you that some humans are so preoccupied with day-to-day survival that they never in their entire lifetime stop for even a minute to be self-aware of themselves. Their mind is constantly focused on other matters, where as, self-awareness necessitates self-reflection. Many people do not have the time or never take the time to self-reflect on themselves.

But what is interesting about other mammal's possible self-awareness: why does an elephant linger around its dead mate for days before he/she moves on. Do they not then become self-aware of their own or their mates existence? Dogs do the same. There are countless instances where a dog bonds so closely with its owner/master/human-companion, that when the human companion dies, the attached dog very soon dies too - maybe like having a broken heart, or suddenly having a self-awareness of being alone?

 

Indeed, I would say you could be self-aware, and not recognize yourself in the mirror.

 

Thanks. I don't know if you only spent the time between my post and your reply searching on Google or not, but this is unimportant. I have not been to your referenced sites yet, but you are now stating things that are true and possible, so you will not be the first to go on my ignore list. (I was objecting to your false statement that scientists had cut to destroy consciousness.)

Certainly there are many cerebral accidents and after effects of violence that have destroyed neural tissue and open windows on the functioning of the brain. No one know very much, (dare I say anything?) about "what is consciousness in neural terms." Dennet wrote a book, boldly entitled “consciousness explained,” about 15 years ago. He is good and well known, so I paid extra for expedited delivery “hot off the press” and was one of the first in general public to read it. - It is wrongly titled.

What you say about the reticular formation is true and easily demonstrated in animals. (Be careful when reading, as there is a surface layer of cells on the thalamus that is unfortunately also called "reticular layer.") You may not know, and are unlikely to learn by searching Google, the modern era of neural knowledge began with Gage (railroad worker with steel “tamping rod” that got blasted thru his jaw and out the top of his head but lived and fortunately was studied by an intelligent doctor for years afterwards.) plus the Russian/ Japan war (around 1900 - I forget when) are responsible for this new era. (That war was first to use steel bullets that went thru brains and left most part still intact, unlike the older lead ones.)

I am reasonably well versed in this area, especially aspects that relate to vision. One thing you may want to look up/ Google search/ is a form of "half consciousness" usually called "unilateral neglect". I have conducted studies on these patients who have had a parietal stroke. They are fascinating - half of the world does not exist for them. (eat only the food on one side of the plate, may try to throw their own left arm out of bed (right parietal stroke), first days after the stroke, as don't want some arm from another patient to remain in their bed, etc.) All that I studied had had stroke years earlier and were not distrubed when only my voice remained as I walked out of their universe. etc. They can turn head (or body) and learn of all space "half at a time" so they adjust well, but must remember to do so.

My studies related to visual processing in the neglected side: They fixated a small cross in center of monitor and to right and left of it a small red or green dots appeared briefly with a tone sounding. They always noticed the one in their existing space, even without the tone, and could very accurately tell the color. When asked to tell the color of the one that appeared on the side that does not exist for them, they protest for the first few trials ("I only heard the tone, but nothing was displayed." "That is silly, nothing there." etc.) however, after a dozen or so trials, most will say red or green with the tone, just making an answer up to please me, they think. The interesting thing is that they are typically correct about 80% or more of the time! I.e. not only is their visual system working well, but its connection to the linguistic system is intact also. They just do not have conscious connection to half the "real world."

Because of this, and many other things, I have a theory about perception, consciousness, "free will," and even what is "reality". - See thread "about determinism" post of 6 October. Warning: it is a "crackpot" theory in that it strongly conflicts with the accepted position of 90+ percentage of all cognitive scientists. If you really do understand your references, I would like your view on my “crackpot ideas.”