Sweet, sweet coevolution

Hey there!  I just wanted to let anyone that happens to stop by know that I will be teaching a field ecology course in Costa Rica over the next few weeks.  We’ll be, um, in the field, so I won’t have access to computers, and thusly, the interwebs.

Hence, and therefore, no new posts until I get back from Central America with heaps of new stories and adventures and amateur photography to share.

I’ve wanted to go to Costa Rica my entire life.  Well, since I was eight and read about the Monteverde Cloud Forest in National Geographic magazine.  And now I get to go!  And I get to teach a course on tropical ecology!  I am stoked.

But what I’m most excited about is the rampant and shameless coevolution in the tropics.  Coevolution is when two or more interacting species evolve together over time.  They can be in an arms race of antagonism (re: the Red Queen Hypothesis), or they can be adapting together because they are mutualistic.  And in the tropics, symbioses abound.  I mentioned a few different kinds in early posts, the zombie ants, the Euglossine bees, the three toed sloth, the acacia ants.

Since symbiosis in general, and mutualisms in particular, are really what rock my boat (so to speak), here are a couple of cool Costa Rican examples:  (NB: I may need to go more in detail after I get back and have great stories!)

Fungus gardens and their attending leaf cutter ants (mutualism):

Leaf cutter ants (genus Atta): photo courtesy of pixdaus.com

The Atta genus of ants, popularly known as leaf cutter ants, collect leaves from many different rain forest tree species and bring them back to the nest, where they cultivate the with a fungus.  The fungus breaks down complex carbohydrates that the ants can’t digest, and the ants eat the fungus.

Antbirds (commensalism — one benefits and the other is not affected):

Spotted Antbird (Hylophylax naevioides): courtesy of galleryofbirds.com

There is a family of birds known as antbirds (Thamnophilidae) with more than 200 species.  There are about 20 species that have been shown to be very tightly linked to army ants (especially Eciton burchellii).  They follow the lines of ants around in the forest and eat all the insects trying to escape.  Yes, it is a sad day for you if you are being pursued by army ants!  If you are not torn up by ant soldiers (see massive mandibles below), you will be quickly snapped up by a Spotted Antbird (see photograph above).

Army ant soldier (Eciton burchellii) photo courtesy of one of the most awesome blogs, myrmecos.net

If you don’t know about army ants, you should read one of the greatest short stories of all time: Leiningen versus the ants.

The fantastic treehopper mimicry (commensalism):

Treehoppers are a family (Membracidae) of true bugs (of the insect order Hemiptera).  They are known for their mimicry of plants.  They often look like thorns or twigs. But sometimes we have no idea why they look the way they do.  See below.

An ant mimic treehopper: courtesy of Nicolas Gompel


WTH Treehopper, courtesy of iheartchaos.com

You can also check out this blog post on wordpress that addresses the treehopper phenomenon.

Those conniving orchids (parasitism?):

You have to love orchids, especially when they trick insects into pollinating them by pretending to be females ready to copulate.


Wasp copulating with a tongue orchid (Cryptostylis sp.) courtesy of webecoist.com

Darwin was pretty fond of orchids too.  He wrote a book titled: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing.

I’ll be back!


courtesy of wikipedia

In January!  With my own photos, hey.  🙂


5 thoughts on “Sweet, sweet coevolution

  1. Pingback: A Myopic Treehopper « standingoutinmyfield

  2. Pingback: Moth Tympanums and Mites « standingoutinmyfield

  3. Pingback: Euglossine bees carrying pollinia | standingoutinmyfield

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