Drafts

Our project was based off of group 2's proposal. We loved their idea and thought it would be really interesting to observe lichen around campus, especially for me, because lichen is not something you pay close mind to every day. The idea that the quantity of lichen could be an indicator of the air pollution was a nice comparison. Counting lichen is fairly straightforward to do, and therefore, we set out to search for lichen at the campus pond and Sylvan woods and compare their differences!

We set up one 4 x 4 plot with flags around those two areas and used a metal grid to count each individual lichen on north facing trees that appeared in the grid - one meter up each tree; depending on how many trees were inside of the plot. We were able to get this equipment from Peter Alpert. So we looked for crustose, fruticose, and foliose, though mostly found foliose and crustose because we did not find any fruticose on the trees we looked at. Our results from T testing showed no significant differences between the campus pond and Sylvan, so this told us that there was no difference between the air pollution in those areas.

Although we all expected Sylvan to have much more lichen, and therefore less air pollution because of how rural it is in comparison to the frequented campus pond, we assume the reason for there not being a significant difference is because we did not go deep enough into Sylvan woods. We took data from the outside, and expect that if we ventured deeper, we might have seen more of a difference that we could have drawn evidence from.

Regardless of complications, the experiment yielded great findings that confirmed hypotheses and predictions from previous research. Taking all the information into account from this study, further experimentation should be administered. Continued research on other nocturnal organisms would allow more insight into the effects of light pollution, which continues to invade the lives of night creatures. A possible avenue could be raising house crickets from eggs and manipulating their circadian rhythms to test if the effect of artificial light on mating behavior changes after tampering with their biological clock. This experiment may be better suited for nocturnal organisms, but it could also be conducted with diurnal animals as a measure to gather more and variant data. Better understanding the negatives of artificial light through an experiment such as this one can help society understand the effects on a widespread scale. This experiment used a 5 watt lamp, but the results could also connect with bright city lights, technology usage, or even different parts of the world (airplane travel or jet lag). Studying just one field of animal behavior can answer many questions about the evolutionary mechanisms organisms have developed, and allows the opportunity for scientists to discover a plethora of new and rich possibilities in behavioral research.

It was imperative to Include the Mann Whitney U-test to justify the evidence despite minor errors. From the data collected, the higher U value calculated using the rankings in table 3 resulted in the rejection of the null hypothesis, verifying that a relationship exists between light variance and mating behavior in Acheta d., and that light is the factor controlling the decrease in frequency. Without the support of using this statistical measure, there would be no means of validating the data as parametric or nonparametric (Jakob et al., 2014). There were 3 possible errors during the experiment. Nevertheless, they did not significantly impact the major findings from the statistical analysis. It was impossible for the dark environment to be completely absent of light, and thus the minimal lighting could have interrupted courting in Acheta d. which in may have weakened the concentration gradient between behavioral displays in the light and dark environment. The experiment was also conducted in a short time frame, and therefore limited the data. Long term studies allow for repeated measurements and are a more powerful method of advancing theory (Kuebbing et al,. 2018), so the allotted time frame in this experiment was not ideal. A third issue in this experiment was the reduction of predetermined sample size, due to high demand for crickets in other lab groups.

The bright light in the habitat of nocturnal Acheta d. reduced courting behavior in all lit trials. When disorienting their entrained rhythm of night time activity (Nowosielski et al., 2003), the crickets did not adjust well, leading to the decrease in courting behavior from both sexes. Even chirping, the intense method of attracting mates (University of Bristol, 2012), was less prevalent. In contrast, the dark environment simulated natural habitat conditions in Acheta d. and therefore did not impact their behavioral patterns. The results from chirping suggest that light is negatively impacting the behavior in these vocal invertebrates, supported by the knowledge of cricket calls being magnified during the evening when there is no light (Forrest, 1980). This experiment also parallels with the results from previous research involving melatonin production in humans (Gooley et al., 2010). Despite not being mutually exclusive, the differing internal clocks of Acheta d. and humans during the night are both disrupted by artificial light: leading to their physiological and ultimately behavioral changes. The differences in the data collected from the lit and unlit conditions demonstrate biological clocks having an acute sensitivity, and is evident that light lead to decreased frequency of mating behaviors because of its disruption of the circadian rhythm.

In this experiment, the objective was to build upon pre-existing research, and determine the effects artificial light has on mating behavior during the active period in Acheta domesticus similar to the results found with Teleogryllus commodus (Botha, et al., 2017). It was hypothesized that bright light disrupts mating behaviors in Acheta d. The hypothesis was supported by evidence from Teleogryllus commodus, and by data from this experiment: concluding that sexual productivity slowed in crickets based on major findings. Specifically, when exposed to a lit environment, all behaviors were displayed less by Acheta d. compared to the dark environment. Afterwards, the data was tested for validity via statistical analysis of the Mann Whitney U-test. The results were statistically significant and the null hypothesis was rejected: confirming that light is a factor decreasing the frequency of mating behavior in crickets.

Frequency of Courting Behaviors — House crickets engaged in fewer mating behaviors while under artificial light when compared to no artificial light. Tables 1 and 2 display the results tallied during the experiment of the three major courting behaviors found in Acheta domesticus, (Tables 1 and 2). Mounting, a common mating behavior, increased significantly in the environment with no light (Figure 1). This behavior yielded the greatest change, whereas pursuing the female was only different by 7 separate instances (Fig. 1).

Statistical Analysis — A Mann Whitney U-test was performed to determine if the difference between the two sets of unpaired, numeric data was significant. All three behaviors were displayed at a higher frequency in the environment with no artificial light. Using the data and rankings presented in table 3, the Mann Whitney U-test indicated that frequency of courting behaviors was significantly higher in the environment with no artificial light than the environment with artificial light (U = 25, p

A new study done by researchers at the University of Sussex in Brighton, UK shows that dogs are able to recognize other dogs from their barks. The researchers were able to see that dogs are able to detect the differences in words that had a slightly different vowel sound due to different accents in the voices and the age of the person calling them. By the way the dogs had putched their ears forward or move towards the speaker when hearing a certain sound was how the researchers were able to tell that the dogs were able to detect the difference. Another finding these researchers were able to discover was that dogs recognize words irrespective of the speaker. The scientists cannot show that dogs actually understand the words we tell them, but are certaintly listening to what we say.

For all these health benefits to be seen, capsaicin has to be regular component of the individuals diet.  Capsaicin tolerance, similar to lactose tolerance, is a trait which evolved over time and some bodies are better adapted than others.  In a study performed with participants suffering from irritable bowel syndrome, the participants with IBS experienced hypersensitivity to capsaicin resulting in an irritated rectum and diarrhea (Gonlachanvit, Mahayosnond, & Kullavanijaya, 2009).  For those whose body is not adapted to handle spicy foods, it is not an advantage for them to consume spicy foods. In Billing and Sherman’s study, there was not as much stress for spices, like capsicum, in diets with cooler average temperatures (1998).  For the individuals who experience IBS which is further irritated by spicy foods, there is an assortment of factors which could have led to this. First, the individual’s ancestors evolved in an environment, like Norway, which led to less pressure for the tolerance of spicy food.  As a result, the mismatch between the environment of evolutionary adaptiveness and novel environment would result in the deleterious results (Nesse, 2008). Since food preference is also affected by environmental and cultural factors, if the individual was not exposed to spicy foods throughout their life, the sudden introduction might be a shock to the individual due to mismatch. 

As well as spicy food tolerance being due to mismatch, it could also be due to the co-evolution with pathogens.  In nature, capsaicin is naturally occuring and could be utilized by humans to fight off pathogens.  Because pathogens evolve at a faster rate than humans, their infections are harder to fight off (Nesse, 2008).  With humans utilizing cultural and behavioral adaptations of spice use in combination with genetic tolerance for spicy foods, humans have better chances of fighting off a pathogen.  In addition, the use of multiple spices in food preparation ensures the maximum lethality of pathogens, reducing their chances of being a recurrent pathogen.     

Due to the increased use of capsaicinoid and tolerance of capsicums in the human diet, other health benefits emerged as a consequence.  In Tsuchiya’s study of the effects of capsaicinoids on membrane fluidity, bacterial growth and platelet aggregation were the two subjects (2001).  The lipid form of capsaicinoids were able to interact with the membrane in bacterial cells, inhibiting their growth (Tsuchiya, 2001). This effect on bacteria could result in capsaicinoids being essential in maintaining a healthy gut biome for an individual who was raised in an environment with a high spicy food tolerance.  Gastrointestinal disease has been reported to be decreased with capsaicin consumption (Deng et. al., 2016). In platelets of humans, rabbits, and rats, capsaicinoids were shown to decrease their aggregation (Truchiya, 2001). Capsaicin has already been proven in other studies to decrease cardiovascular disease (Deng et. al., 2016).  The effects of membrane fluidity could be one of the physiological changes within the body which decreased cardiovascular disease. In China, a study was conducted to determine if chili intake and capsaicin had any effect on the obesity of the population (Shi, Riley, Taylor, & Page, 2017). Although this was one of the first conclusive studies done involving obesity, there was conclusive evidence that chili intake had an inverse effect on obesity and might provide a low cost solution to obesity problems in China (Shi, Riley, Taylor, & Page, 2017).  Through the decrease of obesity, there is a multitude of other health complications that can be relieved. One of the flaws with the studies on the health benefits of capsaicinoid consumption is the lack of physiological understanding within the body of how it alters the health of the individual. Until these pathways are fully understood, there will be a slew of health benefits that are not maximized.