Thursday, 31 May 2012

The Interesting Relationship Between Bees and Humans

Recently, studies have linked two unlikely organisms by comparing their instinctive behaviours and activities. It has been discovered that the neurotransmitters that give humans the thrill-seeking feeling to go and discover new places are also the chemicals that bees release to risk it all to find new food sites. The closest relative to these species are the ocean dwelling flatworms and interestingly enough, they show no signs of “scouting” activities. This means that bees and humans were able to develop similar genes.

As commonly believed, bees within a colony are all categorised under certain “occupations” following orders from the queen bee. New studies have shown that individual bees, such as scout bees go off on their own initiative to leave and forage for more food supplies (and possibly new dwellings). These female bees may search within tree trunks, holes and cavities and may take hours scanning and deciding whether it would be a suitable new location. Once a food site is spotted, the scout will return to her colony and perform a special bee dance, informing other bees of the new discovered location. After her performance, she will leave and hunt down another food site.

Entomologist Gene Robinson and graduate Zhengzheng Liang led the research with the funding provided by institutions such as the National Science Foundation. Studies involved placing bees within a man-made habitat and leaving them for a few days to adapt. When observations began, it was clear to them which bees were the scouts. As Liang added more food sites, only the scout bees would take the initiative, risking themselves to source out the new areas. After looking inside the scout bees, it showed that they presented different gene activities that are also found in thrill-seeking humans. The main focuses were the neurotransmitters – dopamine and glutamate and the increase of messenger molecules (mRNA) in scout bees.

Dopamine and glutamate are substances that send signals between neurons that are found in our brains.  Dopamine drives us to go out and explore but also makes us addicts to substances like drugs. It is in charge of a variety of functions like observing our food consumption and our emotions, signalling positive feedback. Glutamate is a neurotransmitter that is actually the most abundant amino acid found in the brain. Its roles are involved in metabolism including energy production and protein synthesis. Glutamate is also in MSG which is added to food for better flavour and presentation.

Liang also added glutamate and octopamine to the non-scouting bees and observations showed that these bees were beginning to seek out the new food sites, acting as scouts. Inhibiting dopamine in bees also stopped their seeking behaviour.

Robinson’s explanation for these similar genetics in humans and bees was narrowed down to their “evolution of behaviour” explaining how the same molecules have been involved consistently in evolution. The two separate pathways have also allowed organisms to also present contrasting behaviours.

So even though their common ancestor was the marine flatworm which showed no sign of scouting behaviour, bees and humans who follow different pathways have evolved having similar genes due to similar molecules necessary for the thrill-seeking behaviour.

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