A new study has found that fruit fly - drosophila melanogaster - is not just a ‘complex robot’ as previously thought, but an insect with ‘free will’ and spontaneity.

The study was conducted by an international team of researchers including Alexander Maye and Björn Brembs George Sugihara and Chih-hao Hsieh.

Brembs said that it negated earlier beliefs about these insects.

“Animals and especially insects are usually seen as complex robots which only respond to external stimuli. They are assumed to be input-output devices. When scientists observe animals responding differently even to the same external stimuli, they attribute this variability to random errors in a complex brain,” Brembs said.

As part of the study, researchers tethered fruit flies (Drosophila melanogaster) in completely uniform white surroundings and recorded their turning behaviour to show that such variability cannot be due to simple random events but is generated spontaneously and non-randomly by the brain.

The flies did not receive any visual cues from the environment and since they were fixed in space, their turning attempts had no effect.

Thus lacking any input, their behaviour should have resembled random noise, similar to a radio tuned between stations.

The researchers found that the temporal structure of fly behaviour is very different from random noise. The researchers then tested a plethora of increasingly complex random computer models, all of which failed to adequately model fly behaviour.

The team was able to analyse the fly’s peculiar spontaneity with methods developed by co-authors George Sugihara and Chih-hao Hsieh.

“We found that there must be an evolved function in the fly brain which leads to spontaneous variations in fly behaviour. The results of our analysis indicate a mechanism which might be common to many other animals and could form the biological foundation for what we experience as free will,” Sugihara said.

“Our subjective notion of “Free Will” is an oxymoron: the term ‘will’ would not apply if our actions were completely random and it would not be ‘free’ if they were entirely determined. So if there is free will, it must be somewhere between chance and necessity - which is exactly where fly behaviour comes to lie,” Brembs said.

“The question of whether or not we have free will appears to be posed the wrong way. Instead, if we ask ‘how close to free will are we”‘ one finds that this is precisely where humans and animals differ,” Brembs added.

“I would have never guessed that simple flies who otherwise keep bouncing off the same window have the capacity for non-random spontaneity if given the chance,” Maye said.

The findings of the study were published in the May issue of of the open-access journal PLoS ONE. (ANI).

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