Ant executions serve a higher purpose, research shows

February 1, 2013, Rockefeller University

Natural selection can be an agonizingly long process. Some organisms have a way of taking matters into their own hands, or—in the case of the ant species Cerapachys biroi—mandibles.

Researchers at The Rockefeller University and Paris University have found that when a C. biroi ant steps out of line and attempts to lay eggs when it shouldn't, the other will drag it out of the nest and bite and sting it until it dies. And in a new study published this month in , they believe they've discovered why. Rather than being a competitive behavior between ants over who gets to reproduce more, it appears the killing is a means of keeping the whole colony functioning properly. It's a mechanism, the researchers say, that parallels processes in other areas of biology, even inside a single individual—like when the body attacks cancer cells proliferating out of control.

Daniel Kronauer, head of the Laboratory of Insect at Rockefeller, and his colleagues in Paris chose to study C. biroi because of the special characteristics it has. For one, each worker ant in the species can lay eggs—there are no queens. Also, each of its is made up of ants that are genetically identical. All this makes these ant-killings even more surprising. From an , there shouldn't be conflict over who gets to reproduce—with each ant being genetically equal, there's no motivation for reproductive .

Pest control. Members of the ant species Cerapachys biroi will bite and sting a fellow ant until it dies if it tries to lay eggs when it shouldn’t.
"Similar policing behavior has been observed in several other , and over the past decade it has been debated whether the behavior is a way to repress reproductive conflicts between individuals, or if it serves as a to increase efficiency of the whole group," says Kronauer. "These two factors are very difficult to disentangle in other species. But by examining the behavior in Cerapachys biroi we can conclude that, at least in this species, the executions are a colony-level mechanism, because individual differences that might lead to conflict are controlled for."

The researchers monitored 11 C. biroi colonies for 13 months. The ants have a reproductive cycle whereby the whole colony produces eggs at the same time and once the larvae hatch from the eggs, the ants stop laying eggs and begin to forage for food to feed the hungry larvae. The researchers observed the executions when errant ants would continue to produce eggs while others were off looking for food. Several ants would ambush the perpetrator and bite and sting it for several hours or even days until it died.

Upon dissection, Serafino Teseo, a graduate student at Paris University, and his colleagues found that the ants that rebelled had a high number of ovarioles, meaning they had a greater capacity for reproduction. They were also found to be about one month old, indicating that the discretion occurred following their first reproductive phase, when their ovaries were activated for the first time.

"It appears this is an evolutionary mechanism to eliminate individuals who do not respond properly to the normal social cues that tell the ants when to start laying eggs and when to stop," says Kronauer.

Kronauer's lab is interested in illuminating the processes that allow simple biological units to cooperate and form more complex higher-level units. Ant and bee colonies are often described as "super-," because the individual insects cooperate to create an efficient higher-level entity, much as the different cells of a body work together to keep a person alive.

"This system in C. biroi shows striking analogies to immunosurveillance on ," says Kronauer. "In both cases, the individuals—single ants and cells, respectively—that are not responsive to regulatory signals proliferate uncontrollably and are attacked and removed to protect the higher-level unit. It's a fascinating example of how evolution converges on analogous solutions to similar problems at different levels of biological organization."

Explore further: Wood ant queen has no egg-laying monopoly

More information: Teseo, S. et al. Enforcement of reproductive synchrony via policing in a clonal ant. Current Biology online: January 31, 2013.

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4.4 / 5 (5) Feb 01, 2013
It's interesting to speculate what would happen if that self-policing act were not to occur.

Pretty soon one ant would start laying eggs after the others had stopped.
This would mean it's offspring would outbreed the others' and the mutation to continue laying eggs would be propagated to the majority of the next generation.
With then many ants continuing to lay egges ever fewer ants would forage for food which would lead to the collapse of the colony.
(at first i thought it would lead to a queen-like centralization. But now that I think about it collapse would be more likley)
1.8 / 5 (15) Feb 01, 2013
Sounds like what socialists want to do with 'humanity'.
2 / 5 (15) Feb 01, 2013
Humans do this in the context of tribes as well. This is the purpose of bullying, to reduce the chances that defects will survive to reproduce.

I once saw a group of crows in a parking lot, surrounding and attacking one individual that was on its back. I assumed it was a similar activity.

Religions make it even easier to identify and remove those who cannot conform.
1.9 / 5 (14) Feb 01, 2013
I could see some eugenics researcher using this data to mandate human selective breeding programs.
The USG and Planned Parenthood are doing this now with abortions.
2.1 / 5 (11) Feb 01, 2013
Otto, please don't help Jon derail this into an argument about politics. Just let him rant alone.
2.7 / 5 (7) Feb 01, 2013
RyggTard has never so clearly identified himself as an enemy of science.

"Sounds like what socialists want to do with 'humanity'." - RyggTard

It explains the hate he has expressed for science and scientists in other comments he has made.

It also explains is willful ignorance of science and his existence in Republican fantasy land.
2.1 / 5 (7) Feb 01, 2013
You mean selective breeding like the popularity of first cousing marrying in the Parasite Red states?

"I could see some eugenics researcher using this data to mandate human selective breeding programs." - RyggTard
3.3 / 5 (12) Feb 01, 2013
If ants are socialists then they practically prove it's merits by surviving over 100,000,000 years. Good point ryggee!
3.9 / 5 (7) Feb 01, 2013
I could see some eugenics researcher using this data to mandate human selective breeding programs.
The USG and Planned Parenthood are doing this now with abortions.

The only problem with your comment is there are NO eugenics researchers as you use the terms or any scientifically trained individual using his skills towards a eugenics goal.

And your comment about Planned Parenthood and abortions well honestly how would you know that when its clear you never come out of your cave and only get news from Fox and Limbaugh.
4.5 / 5 (4) Feb 01, 2013
Once again, the resident cranks derail another article with their blatantly rule-breaking political bullshit.
1 / 5 (5) Feb 02, 2013
Rumor has it that RyggTard is hold up in a bunker like his Child Molester hero, David Koresh, and is holding a 5 year old autistic boy hostage.


He is upset that the world has not adopted the ideology of welfare queen Ayn Rand, and won't come out until everyone names themselves after a typewriter as Ayn Rand did.

1 / 5 (11) Feb 02, 2013
The only problem with your comment is there are NO eugenics researchers as you use the terms or any scientifically trained individual using his skills towards a eugenics goal.
-That you know of. That you are aware of, is what you mean, yes?
1 / 5 (10) Feb 02, 2013
"Eugenics is the applied science of the bio-social movement which advocates practices that improve the genetic composition of a population, usually a human population. It is a social philosophy advocating the improvement of human hereditary traits through the promotion of higher reproduction of more desired people and traits, and reduced reproduction of less desired people and traits."

-I, and herrnstein, would argue that society has been reconfigured since ww2 along eugenic lines by removing more intelligent people from their incipient cultures and sending them to universities, and from there into professions, where they are encouraged to choose mates with similar abilities.

But even beyond this we can speculate that countries like the US were established to offer the opportunity for the brightest, most ambitious, and most pragmatic people from around the world to abandon their incipient cultures and emigrate. Their children are then encouraged to comingle.
1 / 5 (2) Feb 06, 2013
Watch Randite Republican Paul Ryan answer RyggTard's insane complaint, then move on to denouncing the philosophy of Ayn Rand, and try and then attempt to change topic to avoid his previousy claimed devotion to her cause...

5 / 5 (2) Feb 06, 2013
I could have sworn this article was about ants...
1 / 5 (2) Feb 06, 2013
A member of the "inferior breed", RyggTard foolishly tried to make it about Eugenics.


With regard to Ants, I will speculate.

It is very possible that there is, or was, an advantage to the nest organism, to have reproduction occur at one time for the colony so that labor can be more efficiently organized, or that defense of the colony can be greater during a single period of reproduction.

It is also possible that the ant brain is more easily partitioned into operating modes, one for colony construction and another for reproduction, and that more nuanced modes of operation are not easily evolved from the current local optimum conditions.

The drivers of evolution are many, and most often surprisingly subtle.
1 / 5 (3) Feb 06, 2013
Otto is correct about this of course. America had been an intellectual parasite nation for a long time.

"But even beyond this we can speculate that countries like the US were established to offer the opportunity for the brightest, most ambitious, and most pragmatic people from around the world to abandon their incipient cultures and emigrate." - Otto

However, after WWII there was a period of enlightenment among those who had seen real war, and American Universities became leading educators for the world. Even those who would return to their own countries with the knowledge.

This was a great benefit to the world and the U.S. for a variety of reasons, that are all obvious.

It has, however, most recently become a detriment to the U.S. as American Corporations were encouraged by Republicans to close up their American facilities and move to foreign nations where labor costs were lower, and environmental standards were lower.

Wage stagnation and unemployment are the result.

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