In what order would the 5 senses evolve starting with the first lifeforms? I am talking about the five senses humans are familiar with. I have my doubts whether the first creatures had all 5. My best guess is that touch came first followed by taste, smell, hearing and sight. Each of these in succession was probably developed to combat or perform predation. If senses developed one after the other could it be proof of evolution taking place or are there with us today microscopic life that have all 5?
Sensory evolution
- Thread starter PsychoticEpisode
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Things are not so simple i'm afraid. For instance it is not quite clear yet if eyes have developed several times independently, or just once.
Lots of debate going on regarding this topic after discovering the 'master control gene' for eye development (Pax6).
Lots of debate going on regarding this topic after discovering the 'master control gene' for eye development (Pax6).
There are actually 6 senses, by the way. And I'm not talking about ESP. The sixth sense is proprioception which is muscle/joint sense. It's the sense which allows you to know where your body is at any given time. There are quite interesting disorders related to a loss of proprioception, by the way, but I'll refrain from sharing any stories for the moment. Proprioception is, of course, related to the sense of touch, but is not the same. They have different pathways to the brain and are treated differently in the brain.
As to the question...
Hmm.
Touch would definitely come first. The question would be whether proprioception or classical touch would come first. Proprioception, I think.
Planaria, as far as I know, have only touch (proprioceptive and somatic) and primitive eyebuds.... Ah. But no. They have taste as well, don't they?
That brings another point, of course. Taste and smell are very similar in nature and might blend together into one sense which would bring us back down to five senses again. But, then again, taste receptors are different than smell. Taste being dependent upon actually touching the object while smell gathers particles from the air...
So. What do we have then?
Let me insert taste (with smell on its heels) into first place.
Followed by touch. Proprioceptive then somatic.
Sight next.
Hearing last.
Have you read anything about Trilobite eyes? There eyes were made of calcite crystals. Some were quite complex in their structure. I don't believe that there is any animal with a similar sight organ.
As to the question...
Hmm.
Touch would definitely come first. The question would be whether proprioception or classical touch would come first. Proprioception, I think.
Planaria, as far as I know, have only touch (proprioceptive and somatic) and primitive eyebuds.... Ah. But no. They have taste as well, don't they?
That brings another point, of course. Taste and smell are very similar in nature and might blend together into one sense which would bring us back down to five senses again. But, then again, taste receptors are different than smell. Taste being dependent upon actually touching the object while smell gathers particles from the air...
So. What do we have then?
Let me insert taste (with smell on its heels) into first place.
Followed by touch. Proprioceptive then somatic.
Sight next.
Hearing last.
Have you read anything about Trilobite eyes? There eyes were made of calcite crystals. Some were quite complex in their structure. I don't believe that there is any animal with a similar sight organ.
Indeed, a tricky subject. As you said, maybe touch and taste developed simultaneously?
Paramecium definitely can sense bumping into objects. They also can taste the environment I suppose. But they also have sense of light. hmm...i'm confused...who is with me.
Paramecium definitely can sense bumping into objects. They also can taste the environment I suppose. But they also have sense of light. hmm...i'm confused...who is with me.
Good point on the paramecium.
Single cells do have much more effective sensory mechanisms than might be apparent (in fact I was just reading an article on the newfound importance of cilia in cellular functioning.) But, I wonder how much one could compare the 'senses' of a single cell with the senses of a colony organism? The single cell is purely chemical and there is no neural network with which to process information. Rather it's all a bunch of chemical cues.
Of course, the same can be said for all organisms, in a way (about the chemical nature, that is) but it is far more complicated and not mediated in the same way as with single cells.
I suppose that single cells have every sense but hearing. I've never heard of hearing having an effect on single cells anyway. Could be wrong on that.
The question becomes not which senses evolved first. But rather which order the specialization of single cells took in the development of sense organs. And this precludes the discussion of single cells.
Single cells do have much more effective sensory mechanisms than might be apparent (in fact I was just reading an article on the newfound importance of cilia in cellular functioning.) But, I wonder how much one could compare the 'senses' of a single cell with the senses of a colony organism? The single cell is purely chemical and there is no neural network with which to process information. Rather it's all a bunch of chemical cues.
Of course, the same can be said for all organisms, in a way (about the chemical nature, that is) but it is far more complicated and not mediated in the same way as with single cells.
I suppose that single cells have every sense but hearing. I've never heard of hearing having an effect on single cells anyway. Could be wrong on that.
The question becomes not which senses evolved first. But rather which order the specialization of single cells took in the development of sense organs. And this precludes the discussion of single cells.
invert_nexus said:
One sense has to be more advantageous over the other. In a game of life and death this is important. In a normal situation having more is better.
These are my humble reasons: At minimum, touch indicates to a primitive cell its environment and proximity to friend or foe. Taste could further enhance touch for feeding or procreation purposes. Smelling the presence of other life would be a great advantage over those that need to touch. In whatever environment there are vibrations through movement thus leading to hearing prey or predator before you smell them. Sight, need I say more, to pick up indications of others at the speed of light is a tremendous advantage.
Possibly the first symbiotic relationship that existed between 2 cells, each with different senses, paved the way for more complex colonization and induced the mechanisms required for multi-cellular creatures.
How important is the specialization of a brain to interpret all the senses? So what came first, sensors or sensory interpretation (brain or similar), or did a sensor develop into a brain or central interpretive center?
Seventh sense: electromagnetic fields and receptors generated in fish are used for navigation and to detect prey. Also used to detect different sexes among species of fish for reproduction. Sharks can detect these electromagnetic fields to find prey buried in the sand. Sea turtles orient themselves to navigate and birds are thought to migrate by using the Earth's north/south magnetic field.
Chemoreceptors: responsive to chemical stimuli in the environment - taste and smellbut also include pheromones (chemical messages released into the environmental).
Radiation receptors: ampire bats and some snakes can detect infrared radiation, but since this is a wave length, you could argue it's a form of sight?
All senses involve nerve fibers or sometype of sensory organ. Basic stimula-response would've evolved first: not pain, feel, or touch - just something that caused an electric impulse to be transmitted (something that caused the noticing of an internal or external environmental change).
Chemoreceptors: responsive to chemical stimuli in the environment - taste and smellbut also include pheromones (chemical messages released into the environmental).
Radiation receptors: ampire bats and some snakes can detect infrared radiation, but since this is a wave length, you could argue it's a form of sight?
All senses involve nerve fibers or sometype of sensory organ. Basic stimula-response would've evolved first: not pain, feel, or touch - just something that caused an electric impulse to be transmitted (something that caused the noticing of an internal or external environmental change).
Yes. Extraneous tactile input must come first.
Unless we consider the ability of a eukaryote to detect it's chemical surroundings as either taste or smell.
Assuming not...
There would be no point in knowing where the various parts of an organism are unless it is known what they are ment to be doing, do you follow?
I.e., you dont need to organize your muscles to grasp, say, a cake of soap in the bath unless you can feel its presence. So then proprioception.
Olfactoy perception must come next. Whether it is the human version of the 'nose' or the less refined and so probably later developed sense of taste, in history this would have been the primary method for avoiding danger.
Then aural sense. The definitive defensive and offensive sense. While the cochlea in humans are incredibly advanced, perhaps not so advanced as the ocular sense, but so much more important, since it provides 360deg information, not dependant upon line of sight.
Last, what we probably consider our most important sense, the sense of sight. One of the most advanced optical systems on the planet. It must have taken a long time to develope to fruition.
Perhaps intelligence could have developed without other senses, but an accurate awareness of our surroundings is so important to us now, and yet it is possibly the easiest sense to live without. Think on this.
This is of course, all pure conjecture!
Unless we consider the ability of a eukaryote to detect it's chemical surroundings as either taste or smell.
Assuming not...
There would be no point in knowing where the various parts of an organism are unless it is known what they are ment to be doing, do you follow?
I.e., you dont need to organize your muscles to grasp, say, a cake of soap in the bath unless you can feel its presence. So then proprioception.
Olfactoy perception must come next. Whether it is the human version of the 'nose' or the less refined and so probably later developed sense of taste, in history this would have been the primary method for avoiding danger.
Then aural sense. The definitive defensive and offensive sense. While the cochlea in humans are incredibly advanced, perhaps not so advanced as the ocular sense, but so much more important, since it provides 360deg information, not dependant upon line of sight.
Last, what we probably consider our most important sense, the sense of sight. One of the most advanced optical systems on the planet. It must have taken a long time to develope to fruition.
Perhaps intelligence could have developed without other senses, but an accurate awareness of our surroundings is so important to us now, and yet it is possibly the easiest sense to live without. Think on this.
This is of course, all pure conjecture!
Excellent postulation and I definitely agree with you 100%. What I was considering is what type of sensory perception came first, in simple more ancestrial microorganisms like prokaryotes, not eukaryotes.
One thing of pertinent interest maybe in relation to olfactory sense in humans. We have lost it compared to what exists in other mammals. I can't cite the sources, but I remember reading that dogs (canids: wolf, fox, coyote) can smell over 50,000 more scents than humans. To me that seems astronimical, doesn't it?
One thing of pertinent interest maybe in relation to olfactory sense in humans. We have lost it compared to what exists in other mammals. I can't cite the sources, but I remember reading that dogs (canids: wolf, fox, coyote) can smell over 50,000 more scents than humans. To me that seems astronimical, doesn't it?
valich said:
Hmmm...not really. You are just making wild statements again with no intrinsic scientific value.
Were are not a canine species are we?
You should compare our olfactory sense to other primates to make an honest comparison. Moreover there is such a thing as loss, and there is such a thing as gain. Then the situation depends on the ancestral state.
valich said:
It is just light. Or does something magical happen when valich can't perceive it himself? Or is Valich the normal standard of the universe with which everything should be compared?
(Goldfish can see both infrared and ultraviolet)
Are you sure about the ultraviolet? Surely not UV that does not pass thru H2O.spuriousmonkey said:
If memory serves me correctly they do have a color vision advantage over humans. Most humans have three distinct types of color receptors (the "color blind" person is usually lacking one). Goldfish have four. Perhaps you are correct that their vision spans significantly more than a octave of frequencies (wavelengths) and they need four different color receptors to avoid color confusion. (Human vision spans a little less than one octave of the EM spectrum.)
While we are on the subject of animal eyes, did you know that the octupus has a better design than ours. Not only are the bigger (have higher resolution limit) but their retina are structured sensibly with the photo receptors in front of the blood vessels and neural processling layers (Human eyes have two distinct layers of nerves and all of the blood vessels in the light path to the photosensitive cells.) Their god Neptune knew what he was doing - our God or "intelligent designer" was quite stupid.
Unlike cats and other "night hunters" we do have a black layer behind the photo receptors so that light scattered does not reduce our resolution capacity. For cats etc the lower resolution is a price they pay for inceased sensitivity while hunting in dim light. Instead of a black layer behind their photo receptors they have a reflective one - their photo receptors get two trys at being activated by the entering light (one like ours when it first reaches the photo receptors and a second after it is bouncing back thru them to eventually exit the pupil again and give the appearance that a cat's eye shine in the dark when it is looking at you.
Eagles are also interesting. Not only do the have much sharper vision than humans for motion (small mouse frantically heading for home burrow far below the soaring eagle), they have more than one fovea in each eye. The one like ours is used at altitude and the other, quite some angular distance from it is used during the last phases of capture of the mouse etc.
When you think about the angular rates of change of images on the Eagle's retina in the "set claws into mouse" phase it is amazing that the Eagle can do it with such ease. I do not think any of the IR camers that help man's missile hit its target come close to the Eagle's accuracy and data processing rate during the "catch running /hopping /dogging mouse" phase.
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Paper on UV vision in the goldfish:
Chen, D.-M., Stark, W. S. Electroretinographic analysis of ultraviolet sensitivity in juvenile and adult goldfish retinas, Vision Research, 1994, 34, 2941-2944. PubMed
Chen, D.-M., Dong, G, Stark, W. S. Ultraviolet light damage and reversalby retinoic acid in juvenile goldfish. In Retinal Degenerative Diseasesand Experimental Therapy (eds. J. G. Hollyfield, R. E. Anderson, M. M. LaVail),New York, Plenum, 1999, 325-336.
Spectral sensitivity of Juvenile and adult goldfish (from Chen and Stark, 1994)
spuriousmonkey said:
When have I ever made any socalled "wild statements"? This thread is talking about sensory "evolution": not about the senses that we as humans already have now. You're off base.
Further in my statement regarding dog olfactory sense perception, I specifically stated that I can't remember where I read this. What do you think canids have inside those long snouts? It's like you're trying to fight everything I post. Almost everything I ever post, I've researched; but then if I post those cited research statements as a quotation with the sources, you guys gather your guns and attack. Now you're doing the same thing again for "not quoting the source" or "citing the research study." Make up you're mind.
shut up moron.
Dr. Moron to you, moron.
If only you were funny and not tragic.
there are 4 human senses not listed by aristotle (sight, sound, taste, smell, touch)
they are thermoception (heat), nociception (pain), equilbrioception (balance), and proprioception (bodily awareness)
i only know of 3 non human senses: electroception (detect electric fields), magnetoception (detect magnetic fields), and echolocation (similar to sonar)
as to how they evolved, senses did not necessisarily evolve to combat predation. the eye started as a symbiosis of cells that could detect light, and those organisms were able to obtain light energy better and thus did better.
the problem is there is no anwser. also, a problem with your question is that you assume humans are the most advanced species and that evolution was linear directly towards humans. evolution is highly branching, and humans are in no way the only species that are important in this type of question.
another problem with your question is how you would define a sense.
if a microbe is able to use an external fillament to feel around the envrionment, do you consider that equivalent to touch?
if a microbe regects certain chemicals, do you relate that to olfactory or taste (either, doesnt matter)?
it depends on how you define a sense, and how general that definition is or isnt.
in summary, the main problem i think is that you are assuming that humans are the control/omega species.
they are thermoception (heat), nociception (pain), equilbrioception (balance), and proprioception (bodily awareness)
i only know of 3 non human senses: electroception (detect electric fields), magnetoception (detect magnetic fields), and echolocation (similar to sonar)
as to how they evolved, senses did not necessisarily evolve to combat predation. the eye started as a symbiosis of cells that could detect light, and those organisms were able to obtain light energy better and thus did better.
the problem is there is no anwser. also, a problem with your question is that you assume humans are the most advanced species and that evolution was linear directly towards humans. evolution is highly branching, and humans are in no way the only species that are important in this type of question.
another problem with your question is how you would define a sense.
if a microbe is able to use an external fillament to feel around the envrionment, do you consider that equivalent to touch?
if a microbe regects certain chemicals, do you relate that to olfactory or taste (either, doesnt matter)?
it depends on how you define a sense, and how general that definition is or isnt.
in summary, the main problem i think is that you are assuming that humans are the control/omega species.