Loggerhead turtles have internal GPS

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15 Responses to “Loggerhead turtles have internal GPS”

  1. retrojoe says:

    Perhaps the correct term would be compass as opposed to a satellite receiver?

  2. paul beard says:

    I saw something at Futility Closet a week or so ago on some oysters that were moved from the coast to a location inland, all in the dark.

    The oysters opened their shells twice a day, presumably for feeding, at the time of the high tide in their home beds in Long Island Sound. After two weeks, though, their timing shifted to follow the local tides in Evanston.

    Apparently they had recalibrated using the moon.

    Not having eyes, I assume they were able to detect the moon’s presence through its gravitational pull which, even if Bill O’Reilly doesn’t understand it, is how we get tides. So what else does nature have to teach us?

  3. KWillets says:

    It seems the “internal compass” people are at loggerheads with the “internal GPS” people.  

  4. Listener43 says:

    Frankly, this chelonian gps system gives new meaning the the location: at loggerheads.

  5. James LaFreniere says:

    Heard about this a few months ago from CBC’s Quirks & Quarks radio program. It’s a very interesting listen and I recommend it to anyone as a way to pass time with science news.

    http://www.cbc.ca/quirks/episode/2011/03/05/march-5-2011/

  6. MDwebguy says:

    Does their internal GPS receive periodic updates from Garmin, or TomTom?

  7. dculberson says:

    I bet it’s present in mammals, too.  How else can cats and dogs find their way home from hundreds or thousands of miles away?

  8. kmoser says:

    Freakin’ terrapin navigation. How does it work?

  9. libelle says:

    Heinz Lowenstam and Joe Kerschvink were doing research on this stuff back in the ’80s — specifically, the biomineralization of magnetite.

    A lot of creatures, humans included, have magnetite crystals in cells within their brains.

  10. Chevan says:

    Seems like if this really were internal GPS they’d have a way to sense longitude in addition to latitude.

  11. jhm says:

    Birds also have this sense, and it was discovered that they can ‘reset’ their compass with the rising sun.  This was important as the Earth’s field is by no means static, and indeed had repeatedly switched polarity.  I wonder how undersea creatures manage to overcome this.  It would also seem to suggest that it was a trait of a common ancestor.

  12. turthalion says:

    As cool as this is, I would be *way* more impressed if the turtles had EXTERNAL GPS.

  13. daemonsquire says:

    I have a little problem with the phrasing in your lead paragraph, that may be indicative of a larger problem endemic in science journalism–but you would be a far better judge of that than I.  Maybe the problem is all mine.  You mention “the fact that creatures like sea turtles can sense the Earth’s magnetic field”, but this is followed up in the quoted article with phrases like, “(t)hey seem to hatch with a set of directions”, “(w)hat isn’t known, however, is how they sense magnetism”, “many researchers think that magnetic receptors probably exist”, and “(t)hese might be based on crystals of magnetite”(all emphases mine). 

    There are a few more “might”s and possibilities mentioned, all of which would seem to point to a very believable theory, which, especially in the void of other theories, we might nudge toward fact-hood, in our hearts.  Granted, all the cited uncertainty pertains to the mechanism of this sense of magnetism, not the apparent certainty that turtles and other animals have that sense, to begin with (or that they seem to, anyway).

    Where my beef arises is in that there are other theories.  When we’re already talking about non-material fields, such as magnetism, can we easily discount other such fields, like behavioral fields?  I’m talking, specifically, about Rupert Sheldrake’s theory of morphic resonance, as described in his The Presence of the Past.  I know he’s somewhat poo-poo’d in orthodox science, and I’m just the sort of scientific half-wit that fails to understand why.  As I recall, that book wowed me with it’s opening sections on the history of science and the hazards presumption presents to scientific understanding.  It went on to describe the theory, and itemize the impacts that non-material fields appear to have on organisms, fields which may include morphic resonance, having a bearing on phenomena like animal migration, our experience of memories, the evolution of species, group behavior, and human learning.  Sheldrake’s whole career since then, seems dedicated to developing tests for the theory.

    Anyway, I found it fascinating.  Until we figure out how turtles find their way, I’m inclined to think, “could be morphic resonance”.  Until we figure out how memories are formed and/or stored, “could be morphic resonance”.  Flocks of birds all turning instantaneously on the fly, “could be morphic resonance”.  Until we figure out how magnets work…  Oh no wait, we have that one already, right?  Yeah, well, it’s another non-material field that we can see the effects of, perhaps more easily…  Maybe magnetism explains the rest, too…

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