THE ATTINE ANTS are a clade of New World ants that cultivate fungal gardens for use as a food source. The most widely known group are the leaf-cutter ants, which spend most of their time harvesting slices of leaves that are chewed up and placed in the fungal gardens in their underground colonies. There are many other lesser-known species, and these practice different forms of fungal agriculture. A new study of the phylogenetics of attine ants show that the different methods of fungal cultivation emerged in single events.
Ant fungal agriculture comes in five different forms:
- Lower agriculture: The cultivation of any of a variety of different Leucocoprineae fungi. All fungi known to be cultivated are also capable of independent growth outside the ants’ gardens.
- Coral fungus agriculture: The cultivation of Pterulaceae fungi, a clade of coral fungi.
- Yeast fungus agriculture: The cultivation of yeasts. These fungi normally grow ferally as a web of mycelium, but in ant gardens they grow as globules of single-celled yeasts.
- Higher agriculture: The fungi cultured by these ants appear to be so adapted to garden life that they are incapable of living outside their hosts’ nest. These fungi produce gongylidia, swollen hyphae tips that are harvested by the ants.
- Leaf-cutting agriculture: This is a subtype of higher agriculture. The ants’ activity is so centered upon gathering leaves for their fungal garden that a mature colony is “the ecological equivalent of a large mammalian herbivore in terms of collective biomass, lifespan, and quantity of plant material consumed”.
Schultz and Brady studied the phylogenetic tree of the attine ants and uncovered some interesting findings. First, lower agriculture is the ancestral state for attine ants and dates back to over 50 million years ago. The other methods of agriculture were developed much more recently. Approximately 50 million years ago the Attine ants split into Paleoattine and Neoattine sister clades. Among the Paleoattine ants most retained lower agriculture, but one clade developed coral fungus agriculture about 15 million years ago. This could happen due to accidental introduction of this fungus and loss of the original cultivar. In the Neoattine ants yeast agriculture evolved about 20 million years ago, and a few million years later in the sister clade of the yeast cultivators higher agriculture evolved, although lower agriculture persists among other members of this clade. The leaf-cutting ants themselves evolved from within the higher agriculture ants between 8 and 10 million years ago. This short history helps explain why all leaf-cutting ants known cultivate the same type of fungus.
The authors note that attine ants are not well-studied. Their phylogenetic study demonstrates several relationships not previously known and contradicts some previous theories about attine ant evolution (such as the idea that yeast cultivation is the ancestral condition). Some groups thought to be monophyletic have been shown to be paraphyletic, and these will have to be reorganized. Even with this improvement some of these relationships will probably change in future as we learn more about the attine ants, and the authors even propose that we may discover new fungal agriculture systems in addition to the five already known.
While it was not the focus of this study, the authors mention the distribution of the parasitic fungus Escovopsis among the different types of fungal cultivars. Escovopsis is related to a family of fungi that parasitize free-living fungi. The ancestors of this parasite were probably brought in accidentally with the first fungal cultivars and Escovopsis has evolved as a specialized parasite of ant cultivars ever since. Escovopsis commonly infects fungus gardens, but does not infect yeast gardens. The reversion to yeast growth from mycelial growth may somehow prevent Escovopsis infection, and yeast gardens may have been under selection for yeast growth instead of mycelial growth for this reason. Interestingly, the clade of parasitic Escovopsis infecting higher agriculture ants is evolved from a clade that coevolved with coral fungus gardens (and descended previously from a strain found in lower agriculture gardens) and then was transferred across to the higher agriculture ants. To add a twist to this story, the attine ants have developed a symbiotic relationship with bacteria that live on the ants’ integument and release antibiotic compounds which suppress Escovopsis growth.
This amazing mutualistic network has evolved over the past fifty million years. This study has shed light upon the evolution of the relationship between the attine ants and their cultivars, showing a progression from cultivation of a wide variety of fungi capable of independant growth to cultivation of specialized fungi absolutely dependent upon the ants. Along the way two clades branched out into novel types of agriculture, with one clade cultivating yeasts and another switching to a type of fungus distantly related to its original cultivar. Although the relationship between ants and cultivated fungi started 50 million years ago, major changes have occurred in just the past 20 million years.
Alex Wild at Myrmecos also covered this article today, and includes photographs of various attine ants and their gardens.
Schultz, T.R., Brady, S.G. (2008). Major evolutionary transitions in ant agriculture. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0711024105
48 comments
Comments feed for this article
March 27, 2008 at 12:51 pm
Chris Harrison
Thanks for the write up. Your posts are great.
Coincidentally, I’m doing a project with Atta texana right now for by field biology class.
March 27, 2008 at 9:27 pm
Nimravid
Thanks for the compliment!
When I first read this article I didn’t know that we had any fungus farming ants in the United States. I enjoy writing this blog because in the process I learn a lot.
March 29, 2008 at 5:21 pm
Leaf-Cutter Ants Ally Opportunistically with Actinomycetes « Nimravid’s Weblog
[…] parasitism, symbiosis WHILE THE ATTINE ants are not well-studied, I posted this week about a study into their evolution that revealed the history of innovations in their cultivation of fungus. The attine ants are part […]
March 31, 2008 at 6:45 pm
Attine Ants–Yet Another Symbiont? « Nimravid’s Weblog
[…] symbiosis ATTINE ANTS have been a theme at my blog recently. They first showed up in a discussion of their evolutionary tree, then in a post examining their relationship with the actinomycete bacteria that help protect their […]
June 6, 2012 at 2:06 am
website
I enjoy your wp layout, where did you get a hold of it?
June 21, 2012 at 10:00 pm
the hormone replacement
Hey, I just hopped over to your web page via StumbleUpon. Not somthing I would normally browse, but I liked your thoughts none the less. Thanks for creating some thing worth reading through.
June 22, 2012 at 8:14 pm
marty mills
I feel one of your advertisements triggered my internet browser to resize, you might well need to set up that on your blacklist.
June 22, 2012 at 8:24 pm
cosmetics packaging
pretty beneficial material, all round I picture this is worthy of a bookmark, cheers
June 23, 2012 at 4:42 pm
account
Wanted to drop a comment and let you know your Rss feed isnt functioning today. I tried including it to my Google reader account and got absolutely nothing.
June 23, 2012 at 8:25 pm
silpada designs
I tried looking at your website with my mobile phone and the structure does not seem to be correct. Might want to check it out on WAP as well as it seems most cell phone layouts are not working with your web page.
June 27, 2012 at 1:30 am
click here for
I experimented with taking a look at your site with my iphone and the structure doesnt seem to be correct. Might wanna check it out on WAP as well as it seems most cellular phone layouts are not working with your site.
June 29, 2012 at 7:49 am
exhaustion
I have got one suggestion for your website. It seems like right now there are a few cascading stylesheet troubles when launching a number of web pages within google chrome and firefox. It is operating alright in internet explorer. Perhaps you can double check this.
June 30, 2012 at 1:39 pm
purchase here
A lot of of the remarks on this particular website dont make sense.
June 30, 2012 at 9:09 pm
investigate disney games
Nearly all of the opinions on this particular blog site dont make sense.
July 1, 2012 at 8:30 pm
designer rings
How come you do not have your site viewable in wap format? Can not see anything in my netbook.
July 2, 2012 at 3:53 am
click here
Do youve a spam concern on this internet site; I also am a blogger, and I was asking yourself your situation; we have developed some nice techniques and were searching to exchange options with other people, be positive to fire me an e-mail if planning to pursue.
July 2, 2012 at 3:17 pm
download anime online
When I open up your Feed it appears to be to be a ton of junk, is the issue on my part?
July 3, 2012 at 10:56 am
visit budapest
How do you make this blog site look this awesome! Email me if you can and share your wisdom. Id be appreciative.
July 4, 2012 at 1:56 am
bathroom remodeling phoenix, bathroom remodeling az, phoenix kitchen remodeling, kitchen remodeling az, home remodeling phoenix
Most of the comments on this blog page dont make sense.
July 4, 2012 at 8:19 pm
like i said
Please email me with any hints & tips about how you made this blog look this awesome , Id appreciate it.
July 4, 2012 at 8:57 pm
logo
When I open up your Rss feed it seems to be a lot of garbage, is the issue on my side?
July 5, 2012 at 9:52 am
my how to meet people
Almost all of the opinions on this blog site dont make sense.
July 6, 2012 at 5:47 am
personalisation agenda
You ought to really moderate the comments here
July 6, 2012 at 10:15 pm
speed learning
When I open up your Rss feed it appears to be to be a lot of garbage, is the problem on my part?
July 7, 2012 at 6:53 am
this month
I appreciate your wp format, where did you get a hold of it?
July 7, 2012 at 2:11 pm
wedding dj athens ga
Wanted to drop a remark and let you know your Rss feed is not working today. I tried adding it to my Bing reader account and got absolutely nothing.
July 8, 2012 at 3:06 am
continue reading
Is it okay to place a portion of this in my personal weblog if I post a reference point to this site?
July 8, 2012 at 8:55 am
self development
If you dont mind, exactly where do you host your web site? I am hunting for a great host and your site seams to be extremely fast and up all the time
July 8, 2012 at 8:03 pm
forex rebates info
When I originally commented I clicked the Notify me when new comments are added checkbox and now each time a remark is added I receive 4 messages with the exact same comment.
July 9, 2012 at 1:54 pm
austin sushi
Is it fine to place part of this in my personal webpage if I post a reference point to this web page?
July 10, 2012 at 2:38 am
cosmetic dentistry nyc
I Will have to return again whenever my course load lets up – nevertheless I am taking your Feed so i can go through your site offline. Thanks.
July 10, 2012 at 1:27 pm
wedding venues in devon
The look for your site is a bit off in Epiphany. Nevertheless I like your site. I might have to install a normal web browser just to enjoy it.
July 11, 2012 at 8:08 pm
save on
Is it alright to insert part of this on my personal webpage if perhaps I publish a reference to this website?
July 11, 2012 at 10:48 pm
all inclusive family resorts caribbean
As soon as I at first commented I clicked on the Notify me any time new comments are added checkbox and currently each and every time a comment is added I get four email messages with the exact same comment.
July 12, 2012 at 1:57 pm
spinach recipe
Is it fine to place a portion of this in my weblog if I submit a reference point to this website?
July 12, 2012 at 10:21 pm
analyze shades brookfield
Hey there, I just hopped over to your site through StumbleUpon. Not somthing I might typically browse, but I enjoyed your thoughts none the less. Thank you for creating some thing worthy of browsing.
July 13, 2012 at 2:41 am
sponsor
Do youve got a spam concern on this internet site; I also am a blogger, and I was asking yourself your scenario; weve got created some nice techniques and were searching to exchange solutions with other people, be certain to fire me an e-mail if serious.
July 13, 2012 at 9:37 am
guide to computer chair
As soon as I at first left a comment I clicked the Notify me whenever new comments are added checkbox and currently every time a comment is added I get four email messages with the identical comment.
July 13, 2012 at 9:31 pm
arbonne article
I Am Going To have to visit again when my course load lets up – however I am getting your Feed so i can go through your internet site offline. Thanks.
July 14, 2012 at 12:35 am
your big bear fitness
Do you have a spam issue on this internet site; I also am a blogger, and I was wondering your situation; we now have created some nice strategies and we are looking to swap solutions with other folks, be sure to fire me an e-mail if serious.
July 14, 2012 at 7:22 am
like us on facebook
Im getting a small problem. I cant get my reader to pick up your feed, Im using google reader by the way.
July 14, 2012 at 8:21 pm
snoring doctor in flagstaff
I have got 1 idea for your web site. It seems like right now there are a few cascading stylesheet troubles when opening a selection of web pages inside google chrome and safari. It is functioning alright in internet explorer. Possibly you can double check that.
July 15, 2012 at 8:24 pm
silver hair
If you could message me with any hints & tips about how you made this site look this cool , Id be thankful!
July 16, 2012 at 12:34 pm
sponsor
You should really control the remarks at this website
July 16, 2012 at 9:12 pm
web designers surrey
Wanted to drop a comment and let you know your Rss feed isnt working today. I tried including it to my Bing reader account and got absolutely nothing.
July 16, 2012 at 9:58 pm
close remove frame
I had been wanting to know if you ever considered switching the page layout of your web site? It is very well written; I love what you have got to state. But maybe you could include a little more in the way of written content so people could connect with it better. Youve got an awful lot of text for only having one or two photographs. Maybe you can space it out better?
January 11, 2013 at 4:01 pm
http://tinyurl.com/myakdarke10656
I actually desire to save this particular post, “The Evolution
of Ant Agriculture Nimravids Weblog” on my own webpage.
Will you care in the event I actuallydo? Regards ,Sidney
March 8, 2014 at 8:31 am
Biomass Pellets
Splendid blog!! I learn something new every time I visit.