BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: social behavior

Guppy Social Circles: The Evolutionary Benefit of Tight-Knit Groups

It is often said that humans are social creatures.  But why is this?  How do other species help substantiate the need for social interaction and friendship among humans?  What direct benefits result from strong ties between individuals?  To grapple with these questions, Rob Heathcote, an animal behavior researcher at the University of Exeter, conducted the following experiment.

Guppies swimming in a group of three by Per Harald Olsen, source

Heathcote and his team traveled to Trinidad, an island in the Caribbean that is home to the small freshwater Trinidadian guppy.  But why this place and this species you might be asking.  In response, Heathcote states that, “These guppies live in environments that have tons of predators around, so basically it really sucks to be a guppy. In some places they live, you’ll be watching these shoals of guppies and a predator is attacking them every twenty or thirty seconds or so.”  With the hypothesis that animals form social groups in order to reduce the risk of being preyed upon, the Trinidadian guppy was the perfect specimen.  However, Heathcote sought to investigate whether the benefits of communal living derived from individual relationships (as in humans) or simply safety in numbers.

The team divided 240 female Trinidadian guppies into smaller groups of fifteen, with each group having its own pool isolated from the rest.  Some fish were left alone while others were spooked with a doll version of a predator known as the pike cichlid.  It was recorded that the groups formed by the guppies exposed to the faux predator were smaller on average when compared to the groups that the unprovoked fish formed.  Therefore, one can conclude that the startled guppies fearing for their lives were more likely to establish stronger social connections between one another.  In other words “Fear of predation drives stable and differentiated social relationships in guppies” (Heathcote et al. in Scientific Reports).

So, guppies can congregate in massive groups to blend and reduce their chances of becoming dinner.  However, congregation itself attracts more and more predators.  Alternatively, as seen in the experimentation, they can hide in smaller social circles of three to four individuals, a sort of family where each guppy has each other’s best interest in mind and where the guppies can effectively communicate.  When drawing parallels between the Trinidadian guppy and humans, it is clear that both species form exclusive clans to ameliorate their lives.  In the words of Jason G. Goldman, “Spending time with a few close friends could outweigh the benefits of blending in with the crowd, particularly in dangerous situations.”

The research results in many follow up questions.  Why do some humans choose to isolate themselves from social interaction altogether?  How can this study relate to international relations?  What really makes humans different from more primitive species?

Bees Can Coach Soccer

Even a bee is better at playing soccer than I am. Ecologist Olli Loukola of Queen Mary University of London and his team have taught a number of bumblebees (Bombus Terrestris) to move a wooden ball to a specific point to be rewarded with food: AKA, Bee soccer (boccer?). The scientists had a number of bees in the stands, watching and cheering on the pro soccer players. After watching three intense games, the bees that had originally only attended the pro soccer games were put into the field. It’s a rags to riches tale of a bee that once only dreamed of playing soccer getting a chance to make it pro. Under pressure, the novice bees scored goals nearly every time, truly proving themselves to be professional bee soccer league material. However, bees that did not watch the soccer games beforehand only scored 30% of the time.

Graham Wise, https://en.wikipedia.org/wiki/Bee#/media/File:Tetragonula_carbonaria_(14521993792).jpg

While this seems like simply a fun spin off of the bee movie, it was actually a productive use of the researchers time! The fact that the bees were able to learn how to perform a task shows that they have the ability to pick up on social cues. While it took a while for the researchers to teach the initial pro bee soccer players, the second group learned how to play much faster just by watching other bees perform the task.

In a second type of bee soccer, the researchers put three balls in front of the bees. Two of them were glued down to the table, and the third (which was farthest from the goal) was free to roll. While the untrained bees watched, the coach bees were only able to score using the third ball. However, when three balls that were free to roll were presented to the untrained bees, nearly all of them moved the closest ball to the goal, rather than the farthest one that they had seen the instructors use. This proves that the bees were able to actually think about their actions, rather than just imitate the actions of the bees before them. We may see bee olympics in the near future. Or they might take over the world. Be(e) prepared for both.

Fear in Your Genes

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Scientists at the University of Virginia recently conducted a study that suggests a connection between social behaviors and epigenetic markers. The study of these markers could predict the social dispositions of individuals and predict future social issues.

The gene for Oxytocin receptor (OXTR) has the ability to carry various amounts of DNA methylation tags. Those low in methyl tags have a greater ability to utilize oxytocin and therefore have a less amplified fear response. Those with many DNA methyl tags are shown to exhibit a more exaggerated fear response. More finitely, the amount of OXTR methylation affected the amount of brain activity in the amygdala, fusiform, and insula. These regions of the brain are directly correlated with face and emotional processing. To prove this, researchers conducted MRI scans on healthy participants while showing them pictures of angry and fearful faces.

The study not only proved the importance of studying the possible effects of epigenetic markers on susceptibility and resistance to disease, but it also shed a light on the possibility of brain disorders such as autism, anorexia, and depression being linked to DNA methyl tags at the oxytocin receptor.

Broadly, this study changes the way we look at how our environment and upbringing shapes our future susceptibility to illness and disorders. As scientific investigation into this topic continues and expands, we may be able to predict an individual’s reaction to social situations with the prick of a finger.

Article Source: http://www.genengnews.com/gen-news-highlights/fear-response-may-be-epigenetically-amplified-or-muted/81250914/

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