Ant intelligence; queen does not rule the colony (Introduction)

by David Turell , Saturday, April 18, 2020, 18:58 (1680 days ago) @ David Turell

A very different take on how ant colonies really work, with a direct comparison to computer programming rules:

https://aeon.co/essays/how-ant-societies-point-to-radical-possibilities-for-humans?utm_...

"The ant colony has often served as a metaphor for human order and hierarchy. But real ant society is radical to its core

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"Ant colonies seem the perfect natural instance of a social system governed by division of labour. All known species of ants – now about 14,000 – live in colonies. An ant colony consists of one or more reproductive females, called ‘queens’, who lay the eggs. All the rest of the ants, the ones you see walking around, are sterile female ‘workers’, daughters of the queen and the males with whom she mated.

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"We know now that ants do not perform as specialised factory workers. Instead ants switch tasks. An ant’s role changes as it grows older and as changing conditions shift the colony’s needs. An ant that feeds the larvae one week might go out to get food the next. Yet in an ant colony, no one is in charge or tells another what to do. So what determines which ant does which task, and when ants switch roles?

"The colony is not a monarchy. The queen merely lays the eggs. Like many natural systems without central control, ant societies are in fact organised not by division of labour but by a distributed process, in which an ant’s social role is a response to interactions with other ants. In brief encounters, ants use their antennae to smell one another, or to detect a chemical that another ant has recently deposited. Taken in the aggregate, these simple interactions between ants allow colonies to adjust the numbers performing each task and to respond to the changing world. This social coordination occurs without any individual ant making any assessment of what needs to be done. (my bold)

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"When Wilson introduced the notion of ant colonies organised by the division of labour, he framed it as evidence that natural selection had shaped workers to do the tasks they do best. An ant emerges from a pupa as an adult of a certain size, and stays that size throughout its life. In some species, there are ants of different sizes within a colony. Wilson claimed that task and body type coincide: large ants would be soldiers, smaller ones dedicated to more domestic tasks.

"In fact, the data here are sparse and contradictory. Though the largest ants are often designated as ‘soldiers’, in fights between ant species the smaller species often prevails. A large ant, for example, is helpless if six tiny ones grab each of its legs. In some species in the genus Pheidole, the large-headed ‘soldiers’ show no military inclinations; instead they tend to stay in the nest and use their large jaw muscles to crack seeds. But if there are not enough small ants to go outside and forage, the larger ones will do the same tasks as the smaller ones.

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"...regardless of size, as ant workers get older, they move from one task to another, switching tasks as circumstances require. But switching tasks, either in stages of life or in the short term, is not consistent with organisation by division of labour. However appealing it might be to imagine ant colonies organised by division of labour, the evidence tells us they are not.

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"...the collective process of task allocation in ant colonies is based on networks of simple interactions. For example, in harvester ants, colonies regulate foraging activity, adjusting the numbers of ants currently out searching for seeds to the amount of food available. An outgoing forager does not leave the nest until it meets enough returning foragers coming back with food. This creates a simple form of positive feedback: the more food is available, the more quickly foragers find it, and the more quickly they return to the nest, eliciting more foraging.

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"The system that ant colonies use to organise their work is a distributed process. Like division of labour, distributed processes can take different forms. A distributed process is not the opposite of division of labour – but it’s different in important ways. Primarily, in a distributed process, there is never central control, while in division of labour there might be. A leader can tell one citizen to make candles and another to make shoes. In a distributed process this would happen through local interactions, for example with people who want to buy candles or shoes – creating demand that is filled by an entrepreneur who then meets the demand.

See next entry for continuity. Keep in mind my bold