Drafts

Nutrient cycles in an ecosystem move the key components organisms need to survive. Nutrients generally enter a system through 2 channels. Either the weathering of abiotic materials that release the nutrients from its previous form or atmospheric inputs such as deposition and fixation. These nutrients are then soluble and can be absorbed by plants and microorganisms. Plants and microorganisms end up as detritus after their life cycles are terminated. Before becoming detritus some of these individuals will be consumed by heterotrophs which also inevitably become detritus. After time is allowed to pass the detritus decomposes and the nutrients mineralize and enter the soluble pool again. During this process, some of the nutrients are lost. The nutrients can become leached into the soil or be released into the atmosphere as a gaseous loss. This process repeats as long as nutrients are present in the active pools. If the nutrients stop cycling the ecosystem could experience catastrophic loss in biodiversity.

In order to visualize the available energy and biomass at each trophic level, ecologists use the pyramid model. At each trophic level, beginning with the primary producers on the bottom, a rectangle is made proportional to its value in that ecosystem. In terrestrial ecosystems, the energy and biomass pyramids decrease as each trophic level progresses. The primary producers have the most of both and the tertiary consumers are at the top with the least of both values. Aquatic ecosystems share a similar energy pyramid where the primary producers have the greatest amount and the tertiary consumers have the least. However, the biomass pyramid shows a different pattern. At the lowest trophic level, the primary producers, there is the least amount of biomass and as the trophic levels increase the biomass increases. This is known as an inverted pyramid. A pyramid such as this one occurs in aquatic ecosystems because the turnover rates of the primary producers are much higher. In terrestrial ecosystems, a lot of the biomass is inedible so the turnover rates are slower. 

In my physics class, we are learning about magnetic fields. One of the most interesting things I find about magnets is the inability to separate north and south poles, unlike the ability to separate positive and negative charges. No matter how small you go, even down to the atom, a magnetized object will always have a magnetic north pole and a magnetic south pole. For example, if you cut a bar magnet with a north and south magnetic pole in half, the two halves would both then form a north and south pole. Scientists have never observed a magnetic monopole, which is a particle that has just one magnetic pole whether that be north or south; however, scientists don't know why this is the case and are trying to figure out why this happens if a magnetic monopole cannot be observed.

Based on the premise that since all living things have the same DNA, that DNA from one organism can still be read and expressed when transferred to another organism (genetic engineering). Monsanto is a company that produces genetically modified organisms. They have made plants such that round up, a herbicide and carcinogen, would not be effective against vegetation. This is concerning because we are consuming dangerous compounds. An interesting topic to think about is the ruling of GMOs. GMOs are not considered GMOs if they are produced via CRISPR-Cas9, versus a product produced by a "gene gun" which is considered a GMO because we are taking DNA from one organism and inserting it into another. One example in which genetic engineering can be seen as a positive result is the modification of fast food potatoes. McDonald's takes advantage of genetic engineering to get rid of formaldehyde that can synthesize in potatoes when cooked at a high temperature. This lets us consume fast food safely, while letting companies mass-produce safe food for consumption.

Based on the premise that since all living things have the same DNA, that DNA from one organism can still be read and expressed when transferred to another organism (genetic engineering). Monsanto is a company that produces genetically modified organisms. They have made plants such that round up, a herbicide and carcinogen, would not be effective against vegetation. This is concerning because we are consuming dangerous compounds. An interesting topic to think about is the ruling of GMOs. GMOs are not considered GMOs if they are produced via CRISPR-Cas9, versus a product produced by a "gene gun" which is considered a GMO because we are taking DNA from one organism and inserting it into another. One example in which genetic engineering can be seen as a positive result is the modification of fast food potatoes. McDonald's takes advantage of genetic engineering to get rid of formaldehyde that can synthesize in potatoes when cooked at a high temperature. This lets us consume fast food safely, while letting companies mass-produce safe food for consumption.

in the novel Nadia’s doctor cousin is “blown to bits, literally to bits, the largest of which … were a head and two-thirds of an arm”. The man who sells Nadia and Saeed magic mushrooms is beheaded, then “strung up by one ankle from an electricity pylon where [his body] swayed legs akimbo until the shoelaces his executioners used instead of rope rotted and gave way”. Saeed’s own mother dies while looking in her car for a lost earring, “a stray heavy-calibre round passing through the windscreen … and taking with it a quarter of her head”. These examples of individual terrorism could be easily compared to many cases I have personal experienced with involving my Coptic Otthodox community. The EgyptAir Airbus A320 flying overnight from Paris to Cairo crashed into the eastern Mediterranean Sea on 19 May 2016. All 66 passengers and crew on board Flight MS804 died. My friend, Mariem Tanious’ father passed away during this flight, and they are Coptic Orthodox as well. Nevertheless, my direct cousin who is also my religion and is a famous drummer in Egypt, was held to gunpoint by a terrorist, asking him for all his money. Luckily, the wallet was given and the terrorist had fled.  

Theories for invasive species and why they occur have been hypothesized in ecological research. Some such theories are the enemy escape hypothesis, EICA hypothesis, EDCA hypothesis, Novel Weapons hypothesis, Missed Mutualism hypothesis, Invasional Meltdown hypothesis, Biotic Resistance hypothesis, unusual refuge hypothesis, global competition hypothesis, introduction pressure hypothesis, unintentional screening hypothesis, intentional screening hypothesis and biological control corollary. The enemy escape hypothesis states that species are less subject to specialized predators and pathogens where they are introduced than where they are native. This is due to the lack of selection for a specialized predator where the organism was not existing. The EICA (Evolution of Increased Competetive Ability) hypothesis is where plants evolve to grow faster than other plants. EDCA  (Evolution of Decreased Competitve Ability) hypothesis is where plants evolve to reproduce faster than other plants, but have no competetive ability. Novel Weapons Hypothesis explains how native species have not evolved to be selected for defenses against introduced species. This means that the introduced species defense mechanisms are more likely to target and harm the native species. Missed Mutualism Hypothesis states that the invading species will be less likely to take over it if is introduced without its native mutualists because it no longer benefits from the relationship with them. The opposite is true of the Invasional Meltdown Hypothesis which discusses the idea that if the mutualists of an introduced species are brought with it, the species will be highly invasive and almost always win out. The Biotic Resistance Hypothesis states that introduced species are less likely to be invasive because the presence of native predators, pathogens, and competitors will limit their spread. The idea that specific location yield species that are highly specialized to live there and only there comes into play in the Unusual Refuge Hypothesis, where it is thought that lack of adaption to local stresses limits invasive-ness, then locations with unusual stresses are less invasible. Global Competition Hypothesis simply states that it is more likely that some species elsewhere is a better competitor in a single niche than the local species because of the opportunity for better plants to be located and adapted to any other location on the planet. The introduction pressure hypothesis believes that the greater the number of individuals of a species are introduced and the more times that species arrives, the more likely it is to take hold in the introduced environment. That is because increasing the number of individuals reduces the limitations on the genetic pool of the migrated population and decreases the affects of genetic drift, and interbreeding between previously separate species populations increases fitness. Intentional screening causes certain traits that are more likely to yield an invasive species to be artifically selected for when people pick plants to bring. The unintentional invasion hypothesis deals with the traits that a plant species is likely to have to have survived travel and dispersal to become invasive. Plants that cling to boats and crops and survive travel are likely to be more drought tolerant, more fecund, parasitic to plants that were intentionally brought, and from places disturbed by people and therefore disturbance tolerant. The biological control corollary is the idea that a specialized predator from the native location of an invasive plant can be brought to reduce the invasive-ness of that plant. 

Both between and within populations, human taste preference varies between every individual.  Within humans, an assemblage of factors affect food preference like genetics, environmental conditions, and culture (Robino, Concas, Catamo, & Gasparini, 2019).  Due to advancements in molecular genetics, the understanding of food preference as it relates to sensory perceptions is being uncovered. Not only does genes coding for the taste and olfactory receptors have an effect on food preference but novel genes also have an influence as well (Robino, Concas, Catamo, & Gasparini, 2019).  The connection of novel genes to direct genes shows the complexity of food perception in the body. Through heritability studies, there is conclusive evidence that food preference is heritable but there is another variable that also has an effect on food preference (Robino, Concas, Catamo, & Gasparini, 2019). If there is any advantage to specific foods being consumed, then these food preferences would be selected for and passed down to the next generation.  At the genetic level, DNA polymorphisms are responsible for taste and smell variations between individuals. For example, the TAS2R38 receptor detects bitter taste and just a single nucleotide mutation can lead to a variable taste perception (Robino, Concas, Catamo, & Gasparini, 2019). Within the body, there is a complex system of gene expression interacting with cultural and environmental influences which determine an individual’s food preferences.

Most species of plants that we see on the North American continent today are not native. There are many causes for the migration of plants across the globe, a majority of which humans have a hand in. The basis of a plant being introduced from its native origin to a new location is that humans or other animals bring them, either intentionally or unknowingly. There are several ecological theories as to how this causes invasive species that overtaken nonative land and out compete the preexisting species. Firstly, when humans intentionally bring a plant across oceans and mountains to a new location, we are performing an informed selection of plants that are likely to become invasive. We pick plants that can survive drought to weather the traveling required to move to a new location, plants that grow faster and heardier, are less susecptible to pathogens, and are likely already well suited for the new environment. These traits all lead to a plant that will be highly competetive in the new community and likely will beat native species. Secondly, because an invasive species can travel from any part of the world to the new location and become rampant, the likelihood that another plant somewhere is more specialized and better at survival than the native plant is high. This can be compared to local marathons that are open to a global population, for example, the Boston Marathon. No one from Boston usually wins, because the likelihood that the BEST person is from the exact town that the marathon is heald in, when the entire world's population is allowed to compete, is low, while the opposite is high. 

Within the development of the individual, a variety of factors goes into their tolerance for spicy foods.  Under the assumption that the receptor for spicy food, TRPV1, functions using similar methods of the PTC receptor, there must be some variable expression of this receptor within the body which results in the varying taste preference.  Another factor which would influence the tolerance to spicy foods within the individual is the environmental and cultural surrounding the individual. At the equator, there a higher intake of spicy foods which could lead to learned tolerance for spicy foods during the development of an individual (Deng et. al., 2016).  Together, the genetics and environment of the individual produces a unique food preference.