Writing in Biology

Intelligent design should not be taught in science classrooms today. The first argument which I have heard and was present in Behe's video comes from this ideal that some things in human biology are irreducibly  complex and therefore must have been designed by some sort of intelligence. The problem with this is that you cannot just propose that something must have been designed by intelligence just because we there potentially may be a flaw in a theory. At the very best even if all of Behe's arguments were proven to be impossible to explain due to evolution, he still hasn't setup the foundation of there must be some intelligence behind. This is a common misconception among people who argue for alternative views of origin of the diversity of life other than evolution, it doesn't matter how much you try to poke holes in evolution even if you were to completely disprove it, it doesn't help prove your theory at all. This fallacy is called a false dichotomy and states that either the theory evolution is true or intelligent design is true therefore if we can disprove one theory the other must be true. This simply isn't true in the real world, there are in fact an infinite number of equally plausible explanations to the theory of Intelligent design therefore in order to proposed ID as some sort of reasonable hypothesis we would need to gather data to prove that it ID matches reality better than any of the other countless explanations.

Since its establishment in 1872, Yellowstone has kept records of its bird sightings. In their documents include almost three hundred bird species. Among the birds are raptors, shorebirds, waterfowl, and songbirds. Half of those species next within Yellowstone itself though many of the birds are also migratory. The species reproduction, habitat use, and abundance are monitored in effort to inform the park's caretakers of climate change's effect on the ecosystem. Birds are therefore also good indicator species of the shifts in rising temperatures and seasonal changes. For example, climate change has led to changes from population size, to timing of reproduction and migration patterns.

In this lab, n-propyl propionate was synthesized using propanol, concentrated sulfuric acid, and propionic acid resulting in 51.8% yield of n-propyl propionate. The product had a sharp, but tangy pineapple/pear odor. The yield could have been greater, but one possible explanation for the low percent yield was the possible loss of reagents or products due to evaporation during reflux. The reflux head could’ve been lowered to slow the rate of evaporation.The identification of the product was analyzed through infrared spectroscopy(IR). As one would analyze IR there are specific characteristics that one would notice. The first is that an observed spike around 3000 cm^-1that results from the sp³hybridized C-H bond. The second is that no large absorptions are present after 3000 cm^-1, indicating no O-H impurities present. Thirdly, narrow spikes are located around 1750 cm^-1that represent the C=O bond of the ester. Lastly, there is a unique fingerprint between 800 cm^-1to 1500 cm^-1composed of one large spike around 1200 cm^-1and smaller peaks at ~1000 cm^-1, ~1100 cm^-1, ~1350 cm^-1, and ~1450 cm^-1. The spectrum of the product was almost identical to the expected spectrum of n-propyl propionate. The product spectrum, however, had small indent absorptions at 3500 cm^-1indicating the presence of an alcohol O-H impurity. This would suggest that propanol was still present in the final product. The presence of the alcohol could be due to the lack of clarity within the procedure in removing excess water during reflux as well as removing the excess water through washing. 

In this lab, trimyristin was isolated from nutmeg using tert-butyl methyl ether, resulting in 73.1% recovery. Once recrystallization with acetone was performed to recover 13% from the nutmeg. A second recrystallization was performed to recover 59% of the pure trimyristin. A hydrolysis and acidification reaction was then performed to result in myristic acid with a 13.9% crude yield. The purity of the trimyristin after each recrystallization and that of myristic acid was assessed through melting point analysis. The initial recrystallized trimyristin had a melting point around 54°C whereas the second recrystallized trimyristin had a melting point of 56-57°C. Since the second recrystallization product had the expected melting point, this indicated that the impurities present within the initial recrystallized trimyristin were removed through the second recrystallization procedure and recovered a purer compound. The myristic acid product of the hydrolysis reaction was found to melt at 53°C whereas the expected value of melting for pure myristic acid is found to be 55°C. This would indicate that the acquired product was not completely pure. The amount of trimyristin from the nutmeg was about 73.1% and could be due to the lack of definite time and intensity of the reaction. This subjectivity could also be a reason why the yield of myristic acid was relatively low. It was unclear if the solid needed more stirring or more hydrochloric acid, but either could be the issue. 

The life-cycle of the malaria parasite begins when it bites a human and injects the parasite. Once injected into the blood, the sporozoites direct towards the liver and within 30 minutes, the parasite has successfully invaded the liver cells. The sporozoites then transform into merozoites and multiply rapidly to produce thousands of more merozoites. Shortly after, the merozoites burst out of the liver and invade red blood cells into the bloodstream where they multiply even further. After 48 hours, the amount of merozoites increases to the point that the red blood cells burst, infecting numerous red blood cells. Over the span of 10 days, some merozoites will develop into gametocytes, which are the sexual form of the parasite. When another mosquito sucks up blood from an infected human, they take up the gametocytes, which will mature into gametes in the mosquito's gut.

The internal anatomy of the insect Drosophila Melanogaster bears a few similarities and many differences with mammal anatomy. While the mammalian circulatory system is closed, the circulatory system of Drosophila is open. This means that the blood is not confined to blood vessels, but rather it bathes the internal organs and tissues. Another interesting fact is that the blood of Drosophila does not contain red blood cells. This stands in contrast to mammals, which have hemogloben in their red blood cells to carry oxygen to tissues throughout the body. Instead of relying on the circulatory system for oxygen transport, Drosophila use a tracheal system. Air diffuses through small openings called spiracles, and enters a branch-like structure called the trachea which delivers oxygen to all of the cells. 

Based on the data for characters 1, 2, and 3, the evolutionary relationships among cats, hyenas, and civets cannot be resolved. This is because none of the taxa share traits 1 and 3, and too many of the taxa share trait 2. There needs to be more of a discrepancy between the taxa for a certain trait or traits that allows their relations to be hypothesized. Of the remaining nine traits, 4 and 7 are the only useful ones in reconstructing a phylogeny between these three taxa. This is because these allow the cat and the hyena to be put into a hypothesized relation as opposed to the civet. Traits 5, 6, 10, 11, and 12 are not useful because none of the taxa share them. Trait 8 is not useful because only the cat has it, so the other taxa cannot be compared alongside it. Trait 9 is not useful because all of the taxa in the carnivoran group have this trait, so it does not help distinguish them from each other.

There are four components of NMRs to consider when determining the structure of a compound. In H-NMR, the four components are number of signals, relative areas of the signals, position of shifts, and multiplicity of signals. The number of signals indicates the number of different hydrogen environments in a molecule while the relative areas of the signals indicate the number of hydrogen in each of those environments. The position of the shifts indicate the different functional groups within the molecules. Lastly, the multiplicity of the signals indicate the number of neighboring hydrogens each hydrogen in the molecule has.

Regarding the carnivorans, the character #6, tail, has two character states. In this phylogenetic analysis, an elongated tail is the ancestral character state (scored with a 0) and a short tail is the derived character state (scored with a 1). In phylogeny A, a short tail is hypothesized to have evolved after the split between otters and the group of bears, sea lions, walrus, and seals. This proposes that a short tail is the synapomorphy for the monophyletic group of bears, sea lions, walrus, and seals. In phylogeny B, a short tail is hypothesized to have evolved twice. This is an example of homoplasy. For example, a short tail here is a derived trait for the seals, but it is also a shared derived trait for bears, sea lions, and walrus. However, there are a few separate divergences between seals and this group, and the common ancestor is hypothesized to have an elongated tail. In phylogeny C, a short tail is hypothesized to have evolved twice as well, but then lost in one lineage branch. For example, a short tail is a derived trait for the bears, but it also initially evolved as a shared derived trait for the sea lions, walrus, seals, civets, hyenas, and cats taxa. Cats, hyenas, and civets then lost this short tail trait. This is an example of an evolutionary reversal. In phylogeny D, a short tail evolved once in the lineage to include its monophyletic group branching from seals to dogs, but then this trait was lost later in the phylogeny in otters, raccoons, and dogs. This is another example of an evolutionary reversal. Based on this trait and the parsimony principle, phylogeny A is the most likely. The parsimony principle guides us to the evolutionary tree with the fewest character-state changes, and this is the one usually regarded as the best. In phylogeny A, the tail trait only evolved once in the lineage and was not lost at any point.

            Neanderthals are thought to have disappeared approximately 39,000–41,000 years ago, but due to overlapping chronologically and geographically with modern humans' ancestors, they contributed 1–3% of the DNA of present-day people in Eurasia. In the study by Fu et al., DNA from a 37,000–42,000-year-old modern human from Peştera cu Oase, Romania was analyzed. Although the specimen contained small amounts of human DNA, an enrichment technique was used to isolate genomic sites that were distinct between Neanderthals and present-day humans. They found that  6–9% of the genome of the Oase individual was derived from Neanderthals, more than any other modern human specimen sequenced to date. Three of the chromosomal segments of Neanderthal ancestry were measured to be over 50 centimorgans in size, indicating that this individual had a Neanderthal ancestor as recently as four to six generations back. However, the Oase individual did not share more alleles with later Europeans than with East Asians, suggesting that the Oase population did not contribute substantially to later humans in Europe.