The Research Project was one of my favorite projects throughout my time here at UMass. One reason I enjoyed it so much was how similar this project was to an actual research project, but very simplified in which we still got a lot out of it. I had done cancer research over the summer, and we had displayed our research at the AACR conference in a similar fashion: a poster. I didn’t do too much work formatting and creating the poster itself, so getting this experience was very nice. I also really liked how the overall project was structured: I didn’t feel too stressed, and felt like I could get everything done in the time given. I also learned a lot in this project such as the important elements to include in a poster, and worked on presenting my poster (i.e. elevator speech) to people walking by. Performing the experiment itself was also awesome, and really made for a more engaging project, one in which I actually felt like I was performing an important experiment. Overall, this was a great project.
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Coming into this class, I heard it was a very rigorous course, but you got a lot out of it. Looking back on it, I learned a lot about how to scientifically express various elements needed for a research project. I found it especially interesting to learn about the various ways of attacking a research project because of what I have already accomplished in my career, and what I plan to accomplish later. I thought planarians were a great organism to use for the project because of how interesting they are: they respond to various things you do to them and can view them macroscopically which I think is important! The in-class activities almost always related to different aspects of the project that we were working on which made class time useful. Lastly, there was a lot of freedom in this class, whether it was picking a certain research topic or planning on when you’re going to do what assignments, I really enjoyed doing things, “my way,” in a sense.
The Methods Project was a project that I knew would challenge me off the bat. I had followed numerous methods before in my life, but I had created very few methods from scratch, especially one as detailed as replicating several photos of a specific organism. This project taught me how attention to detail is key in the sciences, as there are so many different variables, or ways in which an experiment can go slightly wrong. We saw this in my methods when the location of the letters on the picture were off, because I wasn’t clear enough in the methods. As I wrote this project, I found it easier to group everything into different paragraphs, and this became especially useful in my discussion when I group everything by factors. I remembered performing an activity in class that was like this, and it really helped the flow in my project. Overall, I personally enjoyed this project. Inkscape was annoying at times, but once when you got it to work, it was a breeze. I also enjoyed seeing what the replicate image someone else created looked like; it was a nice touch.
The first part of the Introduction Pressure Hypothesis says that species that arrive more times or in larger numbers are more likely to establish. When a species is introduced to a new area in large numbers, they can establish themselves into the community easier, and would multiple at a faster rate. The other part of this hypothesis says a species that arrives from many different populations acquires a higher fitness through interbreeding or by dealing with genetic drift often. An invasive species that adapts itself to various areas (populations) would be able to spread easier when it arrives to new ones, since they are used to dealing with this type of change.
In order to have the lowest possible risk of exposure to the contaminants, a species in this food web would need to hunt those individuals in the 3rd trophic level that are older, or possibly individuals in the 4th trophic level that are generally younger. The organisms in these trophic levels contain a little bit of contamination, but not nearly as much as the organisms in the 5th trophic level. The reason I say those individuals that are older in the 3rd trophic level is because as an organism gets older, it accumulates more contamination. The older individuals in this level will contain some contamination, but still provide benefits for the consumer. The 4th trophic level on the other hand has a moderate level on containment, so consuming those that are younger in the trophic level will accumulate less contamination Of course, this individual can still eat primary producers and primary consumers (1st and 2nd trophic levels), as they possess less contamination.
Learning and conditioning are essential tools that allow many organisms to properly react in their environments for survival purposes. In this case, planaria are photophobic, meaning they are sensitive to light. When light is present, a conditioned response (CR) of longitudinal contraction, a sudden lateral turning, or a combination of the two responses in conjunction together. An unconditioned response (UR) such as a shock can also cause planarians to shrink or contract. McConnell and Thompson (1955) first set out to test this combination, by pairing a light and shock stimulus and observing their conditioned responses. Their results helped demonstrate there was no observable difference between the light and shock stimulus when the planarians were tested with each individually. Baxter and Kimmel (1963) helped further by looking at the conditioned response over time that was either paired or unpaired with a light and shock stimulus. The learning abilities of planarians were also tested by Wisenden and Millard (2001),in which a chemical released by the planarians as an alarm cue paired with the odor of fish, which caused the planarians to avoid this scent, as it was now associated with danger.
Being able to respond to various stimuli in an organism’s environment is important for survival. In this experiment, Planarians, because of their photophobic behavior, can respond to a light-shock stimulus. The light stimulus will be paired with the shock in one group, while the other group will be a random combination of light and shock. Also, different shock intensities will be tested with different lengths between the copper wires of the battery. We are hoping to see the planarian condition itself to the shock stimulus, and see variation in the conditioned response when using different shock intensities. This will further prove that planarians have a central nervous system similar to other invertebrates, which researchers believe is true.
Before starting any trials, an apparatus must be set up with a blue light bulb underneath a plexiglass base; the base should be 24 cm above the ground. Copper wires will be attached to the ends of the batteries to produce a shock.
First, 12 planaria were split into two separate groups, a Paired and a Random group, each with six planaria. These groups were tested in pairs (i.e. Paired vs. Random) and each planarian occupied its own container (petri dish). There were twenty 15-s intervals between each presentation of light, and after the light was presented in the Paired group, a shock will be administered each time at the end of the light stimulus (last half a second). The random group received a shock randomly (i.e. flipping a coin; lands on head gets a shock) at the start of each interval. Four trials of this were performed (spread five minutes apart), and whether or not a conditioned response was observed was noted (out of the 20 intervals).
To test different intensities of the shock, the length between the two copper wires were adjusted. The different shock intensities relate to the distance between the copper wires: 1 cm, 2 cm, 3 cm, 4 cm. There were four trials performed for each of the different lengths.
Looking at Figure 1, the conditioned response in the paired planarian group increased over a span of four trials for all four different lengths of the shocking wires. The shortest length, 1 cm, showed the highest conditioned response in planarians, followed by 2 cm, 3 cm, and finally 4 cm. Figure 2 shows the conditioned response in the random planarian group. There is little sign of their being any increase in the conditioned response of these planarians, even though the 1 cm length did show a slight increase over four trials. Overall, in the paired group, there was an increasement in the conditioned response in all lengths of the wire, and a positive relationship between the length of the copper wire and conditioned response.
I do not expect to observe the relationship between regional and local species richness in nature because the slope of the line is greater than 1, which is virtually impossible to achieve in nature. The slope of this line is greater than one because there are a greater amount of local species richness than regional species richness. This is impossible in nature because the spatial area of a region is larger than that of a local area.
Based on this study, I believe that regional processes are the dominant driver of this pattern displayed in the graph. My first reason for this is the fact that the slope is slightly below 1, but does not level off (i.e. plateau) as regional species richness increases. Also, the local richness values are lower than regional richness values, but still increase with them proportionally in Study area 1, which is common of a regional process being the dominant driver in an area.
Based on the equilibrium theory of island biogeography, I believe that the regional species richness on the mainland will affect how many species are predicted to be found on other islands. This theory talks about how immigration and extinction can affect the number of species on the smaller islands scattered around the mainland. Over time, an equilibrium is said to be made between these two rates, which will affect how many species are on other islands.