It turns out, humans aren’t the only species with vast disparities of resources and an unequal division of labor.
Researchers have been sleuthing their way through Argentine jungles and excavating human-sized holes in the forest floor to take a look at the division of labor and resources among one of the world’s largest ant species, the giant South American ant Dinoponera australis. The ant measures over an inch long.
Professors Chad Tillberg, from LINFIELD COLLEGE, Chris Smith, from EARLHAM COLLEGE, and their colleagues have discovered that the social structure of “dinosaur ant” colonies shares some surprising similarities with human societies.
They recorded the behavior and measured body fat content of every individual ant from five entire colonies, while dodging what Tillberg calls “wicked stings,” and found that nutritional status is related to the behavioral role in the colony.
“The leanest individuals in the colony are foragers, with the leanest of the lean foraging the most,” Tillberg said. “Foraging is more dangerous than nest work, and the entire colony depends on this risky, labor-intensive work. The ‘working poor’ are the most nutritionally stressed, and they are not likely to be part of the dominance hierarchy of the colony. When not out foraging, these individuals tend to stay in separate parts of the nest – the chambers closest to the soil surface – rather than the nest chambers deep in the ground.”
That honor goes to the nest workers, who have more stored fat reserves. Deep in the colony, the nest workers are more likely to be part of the dominance hierarchy. The researchers suspect that the most corpulent individual may also be the alpha ant at the top of the hierarchy. Only she is allowed to lay the colony’s eggs. She maintains her position through dominance behavior and intimidation, and when she loses her grip on the top position, there is a scramble among subordinates to assume control of the top post.
“If we think of fat as a type of currency, we see that one group possesses a disproportionate share of the wealth,” Tillberg said. “Rather than an equitable distribution of resources, there are large differences in stored fat reserves, and these differences in wealth are associated with jobs.”
Apparently, the trickle-down mechanism works better among dinosaur ants than humans.
“It’s likely that nest mates are closely related, so the foragers are working to feed siblings,” Tillberg said. “They are all part of a single entity — a super organism – and have a vested interest in helping their affluent nest mates do well, even at their own expense.
“I don’t think we can say the same for humans,” he said. “Judging by the recent protests on Wall Street, it seems that vast wealth inequalities in human societies may have a more destabilizing effect than in ant societies.”
“All across the globe, access to food predicts success,” Smith said. “Nutrition is a common organizer of division of labor, from the most complex to the simplest of societies.”
Previous ant research by Tillberg was covered by The New York Times, Oregonian, MSNBC–Science, LiveScience.com and other news outlets.
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