Joanne's Blog for BIOL 520

The rise of life style associated diseases are typically defined as non-communicable diseases that are caused by external environmental factors. One disease that has been identified to increase in frequency within industrialized countries is irritable bowel syndrome. Irritable bowel syndrome has been identified as a chronic disorder of the large intestine that leads to symptoms of cramping, gas, diarrhea etc. Often, the broadly attributed factor of IBS is increasing poor lifestyle choices such as physical activity, sleep disturbances, and an unhealthy environment. There are a few hypotheses that analyze the reason for the rise of IBS in the world.   One of the hypothesized causes of IBS' rise is due to the lifestyle factor of stress. Stress is a factor that can cause a lot of bodily ailments when allowed to persists since it keeps the body in a constant state of alertness. In an increasingly modern and high paced world, the need to stay busy and be active has been investigated...

While this year was a difficult year, I wouldn't say all was lost for me. While I did lose out on a lot of opportunities (volunteering, shadowing, etc.) that I was going to do to help me prepare for my medical school application, it ended up giving me a well needed expanse of time that I could spend at home to focus on studying the MCAT instead. Since no hospitals were offering opportunities (which makes sense in consideration of the patients and the medical staff), I had no choice but to give my undivided attention to the MCAT. Also, the MCAT was shortened, which was great since the length of time was so crazy to stay focused for (from 7 hours and 30 mins to 5 hours and 45 mins). I didn't realize how well and how long I could study until this past summer, which helped rid me of some of my own personal misconceptions of myself and my ability to focus. I think I was stretched so thin with all of the classes I took that I thought I had an inability to retain information well. It ...

When watching the pipefish, it seems like this role reversal is uncommonly strange. Why would the female have the striking colors while the male appears as the less striking sex? While considering the  sexual dimorphism of some organisms, we know that each sex usually has a distinct pattern difference.   Knowing sexual selection, usually the males appear as these striking colors and displays to attract their future mates to carry their eggs. The answer is not as illogical as one might originally think. Putting two and two together, it seems like the reason for this change is that the female needs the flashy display because they are not the ones carrying the eggs. In fact, much like a sea horse, the father is the lovely pouch that carries the eggs.  Thinking about it in the context of the natural world, this flip in egg carrying does not seem too strange. The males usually invest less in the production process because they are not the ones that have to incubate the eggs an...

As mentioned in the prompt, when one thinks of selection, often they think of it as mechanism that filters out genetic variation. The genotypes with great amounts of fitness are able to move on while those that lack fitness often get kicked out of the running. As a result, we would think that diversity would be eliminated rather than stable or increased. However, genetic variation is allowed to continue by the other mechanisms that are play that are continually keeping variation in the genetic pool.  Genetic drift can result in fixation, but it also can result in the the maintenance of a mutation. In a way, it is almost is a counter to selection by introducing random interferences that allow a certain allele to be kept. It is more of wildcard when it comes to genetic variation. Additionally, there are the factors of mutation. While mutation is not the most reliable mechanism for preventing the erosion of genetic variation due to selection picking off the less fit variations, mutati...

To understand the similarities and the differences between the two theories of evolution, let us first do a refresher on what Motoo Kimura's neutral theory of evolution proposed. The neutral theory proposes that evolutionary changes within species is not caused by natural selection alone. Instead, the driving factor is by genetic drift instead. As a result, mutant genes that arrive are determined by random genetic drift. This theory is not saying all variation is selectively neutral, rather, it is saying that a large portion of mutations are deleterious and would be removed from the population. However, some new adaptive mutations are able to make it, while all the remaining mutations are selectively equivalent (neutral), and their fate is determined by genetic drift. So, the variation we see within and between species are not thought to have effect on the fitness of an organism. We all pretty well know the theory of natural selection, so I'll be succinct. It's the process ...

So around and in Lake Erie, we find that there are some snakes that show some distinct polymorphism. We are asked to interpret this phenotype distribution in the context of the one-island model of migration. To what I understand, the one island model of migration deals with the patterns of migration between the mainlanders and an island. The model is supposed to help look at how the gene pool is affected by the migratory patterns on the island population. Knowing this, we can try break down what might be occurring within the graphs.  First, we know what each letter stands for. The striped phenotype is D. The reduced striping is (B&C). The stripeless base gray color is A. From the information we gained in the text, the mainland snakes showed a large favorability toward the variant striped (D), which allows them to blend into the forest stream environment. We fare also told that the island water snakes tend to be the reduced stripes (B&C) or stripeless gray (A). Additionally,...