Wednesday, February 09, 2005
Annals of entomology: Gliding canopy ants
Tiny ants living in the Amazonian treetops have a remarkable survival strategy - when blown off a branch, they can glide back to the safety of their tree, a new study reveals....
The researchers found that falling ants pivot to fall hind-feet-first in midair and swerve in a J-shaped swoop to land on the bark of their home tree trunk.
Of 120 worker ants dropped from branches 27 metres high, 85% landed safely back on the tree. Even after a brief stumble on impact, most ants marched back to their original location within 10 minutes.
Cool. The scientists estimated that only 8% of the ants would have landed back on the trunk if they were not able to pivot toward the trunk during descent.
By all means check out the video.
Here's to hoping that the TigerHawk Sister weighs in. UPDATE: She does!
4 Comments:
By 
Final Historian, at
Wed Feb 09, 03:16:00 PM:
Fascinating. An amazing evolutionary development. The interesting question would be if they developed this ability after moving high up into the trees, or it was a pre-requisite for them to become tree arboriel.
By Gordon Smith, at
Wed Feb 09, 03:51:00 PM:
Wow. Evolution is confoundingly amazing. Or, sorry if this offends, are you in the Creationist camp? I don't think you are, but in these days of christian political correctness, it's polite to ask.
By TigerHawk, at
Wed Feb 09, 04:24:00 PM:
Screwy, have you ever reading anything on this blog to suggest that I'm a creationist? I'm not sure that I think the theory of evolution is a buttoned down as its most secular advocates claim, but I certainly don't think that the Creator scattered around dinosaur bones and trilobite fossils to test our faith.
By 
, at
Wed Feb 09, 07:05:00 PM:
Sister here. Yes, it is way cool. I have done a lot of work with ants and their fellow hymenopteran parasitic wasps, and have almost ceased to be surprised (but am still delighted) at new discoveries such as this. In response to the question about which came first, there are lots of arboreal ant species, and I'm sure not all do this. As the researcher pointed out, it requires certain structural characteristics, and I agree with him that this particular ant probably just lucked out that it had the right equipment to develop this maneuver. Some arboreal ants may instead have the equipment that allows them to hold on tight a lot better.
The most interesting part to me is that for a worker ant, which does not itself reproduce, to evolve a life-saving measure such as this indicates that there otherwise would be enormous mortality from falling off trees. It would have to happen enough that it would impact the success of the colony. Generally there are so many sources of mortality for workers that they are pretty much just cannon fodder (there is a Tunisian ant species whose workers have an average life span of 6 days).
On a side note, one of the researchers on the project, Mike Kaspari, overlapped with me slightly in my graduate program at U of Arizona (he was finishing up as I started).
Now, as far as the evolution discussion goes (I can't help injecting myself into those), I always strive to clear up the confusion over the term "theory of evolution." Evolution is, by itself, a fact as real as gravity. We have witnessed it repeatedly, e.g. whenever insects develop resistance to pesticides, or bacteria develop resistance to antibiotics, or cold viruses mutate to circumvent our immune system *again.* The theoretical part is the *mechanism* for evolution, and depending on the species, there are many possible mechanisms. Mechanisms for speciation, a particular case of evolution (and I think what most laypeople mean when they use the term "evolution"), are theoretical as well. However, there are several mechanisms of both evolution within species and speciation that are well supported by reams of data collected for the last hundred years.
Personally, I think you should worry about offending someone who disbelieves in evolution as much as you should worry about offending someone who believes that the sun revolves around the earth. There is equal scientific basis for each view.
