ncarbone's blog

Some reptiles such as lizards and snake determine their offspring’s sex by chromosomes. However other reptiles like turtles crocodiles and alligators determine their sex based on the environment around them at the time of the egg fertilization. Different environmental temperatures will result in different sexes. A slight change in temperature can result in dramatic differences in determining the offspring. In a given reptile one temperature rang can result in up to 100% reproduction of one sex. In-between temperatures typically result in a mix of sexes. Hormones have a large effect on the temperature sex determination as well. This is due to the enzyme Aromatase which is responsible for converting testosterone into Estrogen. In European pond turtles aromatase activity is low during low temperatures and high during high temperatures. This correlates which the turtles offspring being mainly male during low temperatures and females during high temperatures.

With the data we could find the weight by sex, balloon length by sex, baloon length compared to weight. We could also calculate the average, standard deviation or mode for the given data set. Constructing a graph or chart based upon the data to show a comparison of the variables would make the data visually easier to analyze.

I elected to take Resource Economics 212 during the fall semester of my sophomore year for my statistics requirement. The thing I remember most about the course was how to do certain functions on Microsoft Excel or in Google Sheets. I remember some of the functions used on Excel, for example I remember how find the mean, mode, average, and standard deviation of a given data set. I also remember some tricks when turning data into graphs or tables. We did a lot of work with probabilities and chance as well, but I do not remember much of the formulas or steps to solve these types of problems. Lastly, we did a group project working with a given set of data is which we had to interpret and come up with a proposition. Overall, I do not recall a lot of specifics from the course though.

Organisms in hot environments use multiple different methods to try and stay cool and keep their body temperature regulated. Panting, which is commonly seen in dogs, helps cool the organism by passing air over their moist tongue. Not only does this keep their mouth cool, but it also helps keep the brain cool which is crucial to an organism’s life. The difference between breathing and panting is the frequency at which it happens. Normal breathing is about 30-40 respirations per minute whereas panting is somewhere between 300-400 respirations per minute. Panting occurs at fast paces for short periods alongside normal slow frequency periods. Panting is not only seen in dogs however. Birds, reptiles, and many other organisms use panting to maintain a cool body temperature.

Organisms in extreme temperature environments have different physiological and anatomical features that allow them to maintain a desired body temperature. In cold environments, many marine mammals have a thick layer of blubber to help insulate their bodies to stay warm. Not only does the blubber act as a thick insulator, but they also have a very integrative blood system which flows through the blubber to help maintain temperature and offer a high degree of control. Marine mammal’s flippers however are not layered with blubber. In order to keep their extremities warm in cold waters they have a counter-current heat exchange blood system. In the flippers each artery is surrounded by a system of veins. As cool blood flows from the extremities back to the heart it is warmed by the counter flowing warm blood from the heart to the extremities. Other ways for organisms to stay warm in cool environments includes: muscular activity, non-shivering thermogenesis, and an increased metabolic rate without muscular contractions.

I thought that the author did a good job introducing his subject and setting up his argument and opinion by laying out the main points that he wished to expand on. However, the first issue that caught my eye was that the figures did not match up with the in-text citations. All 3 figures are labeled as “Figure I” but one in text citation refers to “Figure Ia.” Secondly the author points to many different areas of evolutionary temperature adaptation that need to be studied more, but often concludes with a statement about how we do not have a way to look into certain aspects. He does propose some solutions to these issues, but he also points out one glaring problem. Most of the studies that Clarke references have done studies on aquatic organisms rather than terrestrial species. It does not seem that we can necessarily apply the findings of temperature adaptation in aquatic organisms to those terrestrial organisms.

Clarke then shifts his focus to the ecological constraints of temperature, energetics, and life history. The cost of living for marine organisms in low temperatures is significantly lower than those in warmer tropic temperatures. Based on this, Clarke argues that a temperature related latitudinal variation in resting metabolic rates will lead to higher ecological growth in organisms at lower temperatures. Despite this, there is little data that show a connection between energy flow and food-web structures. He fights for a larger concentration on the implications of macroecological variations in energetics of organisms on food-web dynamics. Linking physiology with macroecology is difficult due to the varied findings in studies. We lack an understanding for how thermal physiology and climate determine biogeography

As far as temperature compensation in the organism-level processes Clarke argues that studies are focused too much on the cellular level and that we do not have an adequate understanding at the molecular level. He proposes to examine the thermodynamic characteristics of the growth processes at a molecular level in order to expand our knowledge on the subject. Temperature compensation is not the only adaptation that Clarke feels is worth understanding. Just as important are the costs of temperature adaptation that come along with compensation. A major cost is the turnover of proteins based on the outcome of temperature, molecular stability, and physiological function. A way to examine these costs is to look at the total costs of existence for an organism excluding reproduction, growth, and activity. These costs have shown to vary with temperature and studies have provided data that point to organisms living in cold temperatures having protein degraded more than those in warmer temperatures.

In the reading by Andrew Clarke, the author gives his own personal opinions on the effect that evolutionary temperature adaptation has on life history theory, food-web dynamics, biological diversity, and biotic response to climate change. His two main goals of the paper are to identify important gaps in our general knowledge of evolutionary temperature adaptation and secondly to explore the consequences of the adaptation of temperature for ecology. Clarke points to a simple model of evolutionary temperature compensation in cellular models to propose two questions. One being how has evolution altered physiology at different temperatures and the other being to what extent has full compensation been achieved? He claims that organisms maintain physiological rates by three different strategies: quantitative, qualitative, and modulation. He then points to the relationship between enzyme function and organism performance as a way of looking into the compensation required. The changes in temperature can potentially cause for metabolic imbalances. However, he points out that in order to have a full understanding of this effect we need to understand the dynamic behavior of the metabolic system in order to know cellular responses to thermal change.

Diabetic neuropathy is one of the major health complications found in people with diabetes across the globe. The many causes and symptoms of neuropathy have been widely studied, but the best way to improve preexisting neuropathy or prevent neuropathy from happening has yet to be found. One method of both preventing and improving diabetic neuropathy that has been studied is exercise. Studies have found positive effects of various forms of exercise on different types of patients with diabetes. Studies have attempted to identify the role and potential benefit of exercise in diabetic neuropathy. A study done by Balducci et al examined both type 1 and type 2 patients with no signs or symptoms of diabetic neuropathy. The study found significant improvements in nerve conduction velocity along with a drop in A1C in the exercise group. They also found that in the exercise group 0% developed motor neuropathy and 6.45% developed sensory neuropathy compared to 17% and 29.8% in the control group respectively. However, a proposed study with subjects experiencing some degree of neuropathy may require a smaller sample size. This study did not have a supervised control group meaning that the exercise group received more face to face time with the investigators and they received information from a qualified physical education instructor. The study also did not include any resistance exercise and the subjects that were tested showed no signs or symptoms of DPN.   To better delineate the benefit of exercise in type 1 diabetes we propose to conduct a 3-month study comparing the effects of aerobic vs. resistance exercise on neuropathy.