The Scientist: NewsBlog:
Magneto-ants pump iron
Posted by Elie Dolgin
[Entry posted at 20th May 2009 12:39 AM GMT]
Researchers have discovered the basis for the magnetic personalities of migratory ants. These social insects integrate magnetic soil nanoparticles into their antennae to help them navigate the forests of South America, according to a study published online today (May 20) in the Journal of the Royal Society Interface.
Most ants communicate through pheromones and other chemical signals to find their way. But some ant species map-read by responding to geomagnetic forces. Pachycondyla marginata, a black, inch-long, termite-hunting ant that ranges from Bolivia to southern Brazil, is one such species. During the cold and dry season, which spans from April to September, P. marginata ants migrate at a 13º angle askew from the magnetic north-south axis. Based on behavioral and magnetic measurements, researchers had suggested that the ants carry a "magnetoreceptor" in their antennae, but it wasn't known what magnetic materials gave the animals their compass bearings. Using light microscopy and transmission electron microscopy imaging techniques, Jandira Ferreira de Oliveira and her colleagues at the Brazilian Center for Physics Research in Rio de Janeiro found that the ants collect ultra-fine-grained iron oxide and aluminum silicate crystals from the soil and incorporate them into three main joints of their antennae. The researchers then devised a theoretical model of the antennae's magnetic sensitivity, and concluded that the amount of magnetic nanoparticles the ants pick up is sufficient to underlie their migratory sixth sense. "They finally localized where [the magnetoreceptor] might be," said Srygley, although the researchers still need to pin down which of the three antennal joints holds the magnetic sensor, he added. Oliveira noted that the second antennal segment is home to the Johnston's organ, which is known to detect motion and might be responsible for sensing magnetic fields, too. The next step, said Oliveira, is to show how the magnetic sensors in the antennae hook up to the nervous system. The iron oxide particles "should be coupled to mechanosensitive structures so as to transmit the information on the geomagnetic field in the form of a torque or force into the nervous system," she wrote in an email. Related stories: [24th March 2008] [19th January 2004] [17th November 1986] |
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Your posts automatically ignored :)
by Eddy Robinson
[Comment posted 2010-06-17 15:38:38]
[Comment posted 2010-06-17 15:38:38]
I don't know much but...
by Donald Duck
[Comment posted 2009-05-26 18:48:37]
[Comment posted 2009-05-26 18:48:37]
First off, this article is filled with an unusual level of waffle language and disclaimers. There is no need to attack this article because it doesn't venture far beyond its boundaries. Attacking the claims of this article could be considered redundant at best; all they claim to know for certain is that certain magnetic compounds can be found in ant antennae. They willingly admit that they have yet to prove what the connection to magnetics and the ant is.
In short, don't be a @#$%% by acting like they are high minded, proud idiots when, actually, they aren't, and you are. Don't try to discredit them until there is something to discredit.
I couldn't personally tell you for certain, but I believe that the theory that some animals, birds and ants included, navigate using the earths magnetic is a pretty reasonable idea. Electric eels harness the power of high voltage and Conan the Bacterium eats lethal radiation, so I see no reason why animals can't make use of magnetic fields.
In short, don't be a @#$%% by acting like they are high minded, proud idiots when, actually, they aren't, and you are. Don't try to discredit them until there is something to discredit.
I couldn't personally tell you for certain, but I believe that the theory that some animals, birds and ants included, navigate using the earths magnetic is a pretty reasonable idea. Electric eels harness the power of high voltage and Conan the Bacterium eats lethal radiation, so I see no reason why animals can't make use of magnetic fields.
Response to "anon..." of May 20:
by Ruth Rosin
[Comment posted 2009-05-21 10:29:17]
[Comment posted 2009-05-21 10:29:17]
Based on what?
Based on the inconvenient fact that a couple of years ago I spent a lot of time debunking one piece of what you may consider "strong evidence", after another, on Scifraud. Overly gullible members, like you, kept challenging me with evermore pieces of "strong evidence". I finally had more than enough of this issue.
You are, however, quite welcome to peruse the Scifraud Archive for my posts, under my name, or under rosinbio. (You would first need to subscribe to Scifraud, for free.)
I won't bother to repeat everything I said there. Here are, however, only two points that should give you cause to pause:
1. Check the meaning of the term "navigate", and you will realise that it not even applicable to the "magnetotactic" bacteria. To navigate by using the earth's magnetic field MEANS to move in ANY desired direction in relation to the direction of the lines of force of that field at any point along the way; which those bacteria never do!
2. A lot of the "strong evidence" concerning migratory birds, is based on studying the birds during the migration period, while they are confined inside "orientation ages", "orientation funnels", i.e. when they are NOT migrating at all. It is logically impossible to determine how birds migrate by studying them while they are prevented from being able to even leave the cage, or funnel. One major problem is that when they actually migrate, the directions of their flights are inevitably affected by the direction of the WIND they encounter at each point along their flight-route. And the experimenters cannot know anything about those wind conditions while they and their tested birds, remain in the lab!
Based on the inconvenient fact that a couple of years ago I spent a lot of time debunking one piece of what you may consider "strong evidence", after another, on Scifraud. Overly gullible members, like you, kept challenging me with evermore pieces of "strong evidence". I finally had more than enough of this issue.
You are, however, quite welcome to peruse the Scifraud Archive for my posts, under my name, or under rosinbio. (You would first need to subscribe to Scifraud, for free.)
I won't bother to repeat everything I said there. Here are, however, only two points that should give you cause to pause:
1. Check the meaning of the term "navigate", and you will realise that it not even applicable to the "magnetotactic" bacteria. To navigate by using the earth's magnetic field MEANS to move in ANY desired direction in relation to the direction of the lines of force of that field at any point along the way; which those bacteria never do!
2. A lot of the "strong evidence" concerning migratory birds, is based on studying the birds during the migration period, while they are confined inside "orientation ages", "orientation funnels", i.e. when they are NOT migrating at all. It is logically impossible to determine how birds migrate by studying them while they are prevented from being able to even leave the cage, or funnel. One major problem is that when they actually migrate, the directions of their flights are inevitably affected by the direction of the WIND they encounter at each point along their flight-route. And the experimenters cannot know anything about those wind conditions while they and their tested birds, remain in the lab!
RE: Stop the Nonsense
by anonymous poster
[Comment posted 2009-05-20 16:04:00]
[Comment posted 2009-05-20 16:04:00]
What nonsense? You base this sweeping statement on exactly what data? There is indeed strong evidence for magnetic navigation in organisms from bacteria to birds.
Stop all this nonsense!
by Ruth Rosin
[Comment posted 2009-05-20 14:12:17]
[Comment posted 2009-05-20 14:12:17]
The only living organisms able to navigate by using the earth's magnetic field are humans, and humans can do it only providing they fashion, purchase, borrow, or steal a magnetic compass.
All claims to the contrary are based on none other than self-delusion fueled by wishful thinking.
Whatever, if anything, ants may do with particles of iron has nothing to do with any magnetic sense.
All claims to the contrary are based on none other than self-delusion fueled by wishful thinking.
Whatever, if anything, ants may do with particles of iron has nothing to do with any magnetic sense.
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