1. Joined
    19 Jul '08
    Moves
    77354
    03 Dec '11 22:36
    Just wonder how evolutionist explain the little piece of iron that's in the brain of many animals but specificly the amazing Pacific Salmon that are able to navagate the 2000 or so miles from out in the Pacific by using the earths magnet field to the exact river outlet that they need to follow upstream to spawn? And even more amazing is if they come to a delta where many rivers might be coming together, they then use their sense of smell to find their exact river and then go upstream.
    Soooooooo exactly how did this just happen for these amazing fish?
  2. Standard memberwolfgang59
    Infidel
    Dunedin
    Joined
    09 Jun '07
    Moves
    45641
    03 Dec '11 22:471 edit
    Originally posted by galveston75
    Just wonder how evolutionist explain the little piece of iron that's in the brain of many animals but specificly the amazing Pacific Salmon that are able to navagate the 2000 or so miles from out in the Pacific by using the earths magnet field to the exact river outlet that they need to follow upstream to spawn? And even more amazing is if they come to a ...[text shortened]... ver and then go upstream.
    Soooooooo exactly how did this just happen for these amazing fish?
    Evolutionists may or may not (yet) be able to explain the evolution of magnetoception in animals but that would not negate the theory would it? After all gravitation existed before Newton.

    I guess you have picked on magnetoception because it is a poorly understood sense - however it has been observed in very primitive life (bacteria, fungi) - so it would be surprising if natural selection did not produce higher organisms with this ability. (As you point out it is an amazing ability and one which would favour the procreation of individuals with it over those that did not have it)
  3. Joined
    19 Jul '08
    Moves
    77354
    03 Dec '11 22:55
    Originally posted by wolfgang59
    Evolutionists may or may not (yet) be able to explain the evolution of magnetoception in animals but that would not negate the theory would it? After all gravitation existed before Newton.

    I guess you have picked on magnetoception because it is a poorly understood sense - however it has been observed in very primitive life (bacteria, fungi) - so it wou ...[text shortened]... d one which would favour the procreation of individuals with it over those that did not have it)
    So your saying that the ancient ancestors of the Salmon had this ability also?
  4. Standard memberavalanchethecat
    Not actually a cat
    Joined
    09 Apr '10
    Moves
    14251
    03 Dec '11 23:08
    Originally posted by galveston75
    Just wonder how evolutionist explain the little piece of iron that's in the brain of many animals but specificly the amazing Pacific Salmon that are able to navagate the 2000 or so miles from out in the Pacific by using the earths magnet field to the exact river outlet that they need to follow upstream to spawn? And even more amazing is if they come to a ...[text shortened]... ver and then go upstream.
    Soooooooo exactly how did this just happen for these amazing fish?
    Do you expect these 'evolutionists' to be able to detail the development of every characteristic of every species on the planet?
  5. Joined
    29 Dec '08
    Moves
    6788
    03 Dec '11 23:091 edit
    Originally posted by galveston75
    Just wonder how evolutionist explain the little piece of iron that's in the brain of many animals but specificly the amazing Pacific Salmon that are able to navagate the 2000 or so miles from out in the Pacific by using the earths magnet field to the exact river outlet that they need to follow upstream to spawn? And even more amazing is if they come to a ...[text shortened]... ver and then go upstream.
    Soooooooo exactly how did this just happen for these amazing fish?
    Is this an unfinished argument from amazement, against biological evolution? If so, it is a subcategory of the argument from incredulity.

    "The argument from incredulity is a logical fallacy that essentially relies on a lack of imagination in the audience."

    http://rationalwiki.org/wiki/Argument_from_incredulity

    This forum is a somewhat good source of teachings in fallacies of argumentation.
  6. Joined
    19 Jul '08
    Moves
    77354
    03 Dec '11 23:21
    Originally posted by avalanchethecat
    Do you expect these 'evolutionists' to be able to detail the development of every characteristic of every species on the planet?
    I have to ask.....
  7. SubscriberSuzianne
    Misfit Queen
    Isle of Misfit Toys
    Joined
    08 Aug '03
    Moves
    35519
    03 Dec '11 23:29
    Originally posted by galveston75
    Just wonder how evolutionist explain the little piece of iron that's in the brain of many animals but specificly the amazing Pacific Salmon that are able to navagate the 2000 or so miles from out in the Pacific by using the earths magnet field to the exact river outlet that they need to follow upstream to spawn? And even more amazing is if they come to a ...[text shortened]... ver and then go upstream.
    Soooooooo exactly how did this just happen for these amazing fish?
    ummm, what "little piece of iron"? Papers such as this: http://www.ncbi.nlm.nih.gov/pubmed/20144612 have shown that the homing mechanism of Pacific salmon is olfactory in nature.

    And it's well-known that the Pacific salmon and trout diverged from other salmon genera in the Miocene era, about 20 million years ago, co-existant with topological changes in the pacific northwest. It's logical to assume the ancestors of the Pacific salmon also had these homing mechanisms in place. I do not know how far back this homing ability goes.
  8. Joined
    19 Jul '08
    Moves
    77354
    03 Dec '11 23:411 edit
    Originally posted by Suzianne
    ummm, what "little piece of iron"? Papers such as this: http://www.ncbi.nlm.nih.gov/pubmed/20144612 have shown that the homing mechanism of Pacific salmon is olfactory in nature.

    And it's well-known that the Pacific salmon and trout diverged from other salmon genera in the Miocene era, about 20 million years ago, co-existant with topological changes in had these homing mechanisms in place. I do not know how far back this homing ability goes.
    I actually just watched a TV documentary on this and so far have only found this info. But I'll keep looking. Thanks.

    Salmon migration: Using magnetic sense?

    One of the mysteries of nature is how salmon manage to navigate in the oceans and return to spawn in the very same streams from which they came. It is known that the odor or taste of the particular stream plays a role. Salmon can home-in on the smell of “their” stream if they are sufficiently close to its mouth so that the water has not been diluted to the point where it is unidentifiable.

    But how can odor play a part when the fish migrate over thousands of miles in the open ocean and cross ocean currents which destroy any possible “trail” that may lead them back? At any rate, it is known that salmon do not follow meandering paths back “home” to answer the spawning instinct, but travel directly to their spawning grounds by the most direct route when sexual maturity occurs.

    What is it that points them in the right direction? Probably there is more than one homing mechanism that fish use to find their way. An olfactory “imprint” is made on smolts as they leave their home stream. This enables them to identify it by smell as they approach it later from the ocean. But to approach the stream mouth from the open sea, at least one other imprint must first be made in order for them to arrive in the general area. It has been shown that some fish are remarkably perceptive of the Sun’s azimuth and altitude, and that they are sensitive to the time of day. Under ideal conditions, this would permit a method of determining geographic north. But in a region where overcast conditions predominate (as they do in the North Pacific and Bering Sea), and because the fish swim at night and move into deeper water during the day, celestial clues are not consistently available. Therefore another means of correcting navigation is probably used. It is strongly suspected that the ability to sense the earth’s magnetic field may provide this additional method.… Extrapolating these findings to the migration process, the conjecture is that, after the salmon fry have grown to smolts and entered salt water, chemical and hormonal changes occur which imprint upon the fishes’ nervous system a “memory” of its magnetic latitude and longitude at the time that it enters the ocean.

    (((There appear to be two possible ways by which the magnetic field can influence a fish’s nervous system. The first is that the ferromagnetic mineral magnetite in the creature’s brain may function as a biological compass which is ‘set’ at the time of entry into the ocean (magnetite occurs across the biologic spectrum from bacteria to dolphins). The information retained is the vertical and horizontal components of the Earth’s magnetic field at that point, and the declination of the horizontal component, which is the difference between magnetic and true north, presumably determined by the Sun. These factors taken together provide a combination that is unique for any geographic location.)))

    —LARRY GEDNEY


    But my question is, this is such a remarkable thing that so many life forms have but how did this just happen? At one point in this evolutionary trip for the Salmon, did they always have this ability?
  9. Standard memberRJHinds
    The Near Genius
    Fort Gordon
    Joined
    24 Jan '11
    Moves
    12694
    04 Dec '11 00:00
    Originally posted by galveston75
    Just wonder how evolutionist explain the little piece of iron that's in the brain of many animals but specificly the amazing Pacific Salmon that are able to navagate the 2000 or so miles from out in the Pacific by using the earths magnet field to the exact river outlet that they need to follow upstream to spawn? And even more amazing is if they come to a ...[text shortened]... ver and then go upstream.
    Soooooooo exactly how did this just happen for these amazing fish?
    That's easy for them. Like every thing else, it just is.
  10. SubscriberSuzianne
    Misfit Queen
    Isle of Misfit Toys
    Joined
    08 Aug '03
    Moves
    35519
    04 Dec '11 00:052 edits
    Originally posted by galveston75
    I actually just watched a TV documentary on this and so far have only found this info. But I'll keep looking. Thanks.

    Salmon migration: Using magnetic sense?

    One of the mysteries of nature is how salmon manage to navigate in the oceans and return to spawn in the very same streams from which they came. It is known that the odor or taste of the parti ...[text shortened]... ppen? At one point in this evolutionary trip for the Salmon, did they always have this ability?
    I'm not wholly convinced Pacific salmon have this ability (magnetoreception). Even though these magnetoreception studies were in 2007-2008, there were experiments done as far back as 1998 where some salmon were blinded, and some were fit with a magnetic ring which interfered with magnetoreception. Their olfactory systems were unimpaired. Some of the blinded ones were found in their natal area after an average of 5 days. Some of the ones fitted with the magnetic ring were found in their natal area after an average of only 3 days, suggesting that the homing ability is less magnetic and more using visual clues.
  11. Joined
    31 May '06
    Moves
    1795
    04 Dec '11 00:08
    Pigeons and sea turtles on the other hand definitely can detect the earth's magnetic field.
  12. SubscriberSuzianne
    Misfit Queen
    Isle of Misfit Toys
    Joined
    08 Aug '03
    Moves
    35519
    04 Dec '11 00:09
    Originally posted by googlefudge
    Pigeons and sea turtles on the other hand definitely can detect the earth's magnetic field.
    This is true, and well established. The data on salmon is sketchy at best.
  13. Joined
    10 Jun '11
    Moves
    3829
    04 Dec '11 00:14
    there are many animals with amazing senses. animals for example, discovered sonar and echolocation long before humans did.

    when it comes to iron or more specifically, magnetite many species make use of this evolution, including humans who have magnetite in their nose. it helps with orientation and navigation by using earth's magnetic field. some have this sense better developed than others.
  14. SubscriberSuzianne
    Misfit Queen
    Isle of Misfit Toys
    Joined
    08 Aug '03
    Moves
    35519
    04 Dec '11 00:241 edit
    Originally posted by VoidSpirit
    there are many animals with amazing senses. animals for example, discovered sonar and echolocation long before humans did.

    when it comes to iron or more specifically, magnetite many species make use of this evolution, including humans who have magnetite in their nose. it helps with orientation and navigation by using earth's magnetic field. some have this sense better developed than others.
    I wouldn't exactly call this an evolutionary advantage for humans, though, would you?

    I mean I don't think I've ever navigated to somewhere by my nose. On second thought, though, I do have a good sense of where north is all the time. In school, we did experiments on this where people were blindfolded and spun around until disoriented and then asked to point north. I recall being right twice out of five attempts, which was far more than anyone else in the class. The teacher called it coincidence. The class average was zero out of five. A few kids got it right once.

    But I'm guessing my life isn't going to come down to being able to guess north while blindfolded.
  15. Standard memberRJHinds
    The Near Genius
    Fort Gordon
    Joined
    24 Jan '11
    Moves
    12694
    04 Dec '11 00:28
    Originally posted by VoidSpirit
    there are many animals with amazing senses. animals for example, discovered sonar and echolocation long before humans did.

    when it comes to iron or more specifically, magnetite many species make use of this evolution, including humans who have magnetite in their nose. it helps with orientation and navigation by using earth's magnetic field. some have this sense better developed than others.
    Evolution is used to explain everything for you guys. Actually it does not
    explain anything.
Back to Top