The heterozygote advantage and genetic drift concepts have aided inheritable diseases such as hemochromatosis and cystic fibrosis. Hemochromatosis is a hereditary disorder in which the body. The disorder is a heterozygous compound which dates back to the Viking era. In order to survive in the iron weak environments of northern Europe, their bodies developed the hemochromatosis mutation
The theory that diabetes is a response to cold adaption is based upon the idea that our European forefathers were able to survive an ice age due to this disease. Around 12,000 years ago, the world fell into an ice age that lasted three years. Named the “Younger Dryas” after the Arctic wildflower, the harsh cold spread from the Arctic all the way down to modern day Portugal. For populations that had situated up north, this ice age was an unexpected catastrophe. In order to survive the sudden cold, their bodies would have had to developed some type of adaptation to maintain as much heat as possible and not freeze. In this case, the adaptation of diabetes would make a reasonable response. There are two main types of diabetes: type 1 diabetes and type 2 diabetes. While there are differences among these different types of diabetes, they all deliver the same problem. They do not produce enough insulin for the amount of glucose in the body of an affected individual. In turn, the amount of water in the body goes down while the amount of glucose goes up. Such an adaptation could be quite useful at a time of the “Younger Dryas”. For one, the reduced amount of water in the body meant that less of a chance of ice forming in the bodies of the affected person. Since individuals with diabetes urinate frequently, in order to excrete as much of the extra glucose as possible, there is less water inside the body to freeze over. Furthermore, since the temperatures that the affected individuals would have been living in was below freezing, their bodies would be able to accumulate a substance known as brown fat. Brown fat is a substance that immediately converts the glucose into heat. Individuals affected by diabetes have more glucose which means they are able to produce heat for much longer than individuals who aren’t affected. While the theory that diabetes is a
a)The human skin protects the body’s folate levels while also creating vitamin D from penetrating UV rays. Folic acid helps in the process of replicating DNA when cells divide, however, it is destroyed in the presence of UV rays penetrating the skin. In order to combat this problem, cholesterol is converted into vitamin by ultraviolet B rays in times of the summer. Individuals who live in areas of high sunlight usually have more darker skin. The darker the skin, the less ultraviolet rays are able to penetrate the skin which means less vitamin D. However, individuals with darker skin have a gene called apolipoprotein E which is able to maximise the volume of cholestesterol in the blood. This means that bodies of darker skinned individuals can convert as much cholesterol into vitamin D with what little sunlight their bodies absorb. The compromise in this situation is that the elevated levels of cholesterol in the blood leads to a higher risk of heart disease and strokes.
b) In the case of alcoholism and clean water, the different water purification processes of our ancestors played an integral role on our resistance to alcoholism. When people drink alcohol, their body goes through a phase of breaking down the alcohol molecule to acetate and then converting the acetate molecule into fat, carbon dioxide, and water. For individuals with European ancestry, their bodies are more easily able to break down the alcohol molecules they drink. This is because their ancestors used to purify their local water supplies by way of fermentation. The alcohol that was produced in the fermentation process, made its way into the local water supplies. Coincidentally, by drinking the water that was full of alcohol molecules, the Europeans were able to build up much a tolerance to alcohol. On the other hand, individuals of Asian descent are not as able to tolerate alcohol as Europeans. This is due to the fact that their ancestors used to boil water in order to make it safe to drink. In turn, their bodies are not able to break down the alcohol molecules as efficiently as they haven’t had much experience with alcohol. Furthermore, individuals of Asian descent have genetic variation of alcohol dehydrogenase, an enzyme used to break down alcohol into acetate, labeled as ALDH2*2). Compared to those
c) Salt is a very important molecule for humans as it helps store and regulate the amount of water in our blood. Individuals who are able to retain higher amounts of salt, are able to store a larger amount of water within their bodies. For example, during the time of the slave trade, Africans who had been captured had a cruel experience on their journey to America. Underfed and dehydrated, many had died on the voyage. However, individuals whose bodies were able to retain salt were just barely able to live through the experience. This is because the salt in their bodies were able to retain just enough water to keep them from dying from dehydration. While they were able to survive, there were also many negative effects of the voyage. For one, the blood pressure of African’s is very reactive to salt. This is a negative effect for many African-Americans as many American dishes are high in salt. Too much salt can lead to a disease called hypertension, a disorder that increases the risk of kidney failure.
d) Individuals with sickle-cell anemia are able to avoid harmful diseases like malaria, due to sickle blood cells. Those affected with sickle-cell anemia have sickle shaped cells that do not provide a preferred setting for the malaria parasites to live. However, while the disease is able to prevent against other diseases like malaria, having sickle shaped blood cells is also a huge burden to carry. The odd shape of the blood cells makes it hard for blood to travel throughout the body. Often times, the blood in an affected individual begin to clog up in the blood vessels which can cause a lot of pain.
e) In order to prevent from being ingested, different types of plants have specific tactics to defend against predators. The phytoestrogens (clovers, sweet potatoes, and soy) defend itself by damaging the reproductive capabilities of the predators. As the name suggests, phytoestrogens possess an abundance of estrogen-like compounds which then neuter the animal’s ability to reproduce after they are eaten. The cyanide precursor compounds contain different types of poisons to ward off predators. For example, the cassava is an asset in the diets of many different cultures. However, during times of drought, the cassava will be much higher in cyanide.The Jimsonweed plant acts as a hallucinogen to ward off predators. Those who accidentally consume Jimsonweed, will experience hallucinations and will act more lunatic. Wheat, beans, and potatoes are amylase inhibitors which hinder on the body’s ability to break down carbohydrates. Chickpeas and some grains are protease inhibitors which hinder the the body’s ability to absorb protein. Chilli holds a chemical called capsaicin which affect the nerve fibers that sense pain and heat. Any animal that eats this plant will feel a burning sensation as well as begin to feel some heat. Lastly, celery plants hold a chemical called psoralen. When exposed to the sun, the psoralen chemical releases a toxin which causes extreme sensitivity to the sun.
a) The parasitic worm, Dracunculus medinensis, gain their reproductive success by latching onto a human host and releasing its larvae. It begins the process by releasing larva, outside of the human host, that are eaten by water fleas. The fleas are then ingested by a human where they are killed by the digestive system. However, the larva inside the fleas are not killed by the digestive system and begin to grow inside their host. Once they become adults, the female worm begins to secrete acid and dig it’s way into the skin of its host. This causes a irritable, burning feeling which causes the host to want to cool the burn by pouring water in the affected area. However, this is all part of the larvae plan to reproduce. Once they feel the water coming, the adult larvae within the host are then able to release their larvae into the host to follow the same journey.
b) The Hymenoepimecis argyraphaga are parasitic wasps native to Costa Rica that achieve reproductive success by preying on spiders. The process starts out when an adult wasp stings a specific species of spider called the, Plesiometa argyra, injecting the spider with its larvae. The larvae then begin to feed off the spider’s bloodstream before injecting the spider with chemicals before its time to cocoon. The chemical they inject into the spider changes the normal behavioral patterns of the spider from weaving orb like webs to a cocoon for the larvae. Once the coocoon is made, the spithe larvae sucks all of the blood from the spider, throws away its lifeless body, and then
c) The parisitic worm, Dicrocoelium dentriticum, has to make quite a long journey before reaching the destination of reproductive success. These worms live inside sheep and cattle and must find a way of excreting the larvae out of the sheep in order to ensure reproductive success. This is because once the sheep dies, the worms will have no way of reproducing and end their bloodline as the sheep dies. The journey begins with the adult worms laying eggs in the guts of sheep. The eggs are then excreted with the waste of the sheep before being eaten by a snail. The eggs hatch inside of the snail where they are then excreted out as slime by the snail.
The discovery of transposons have proved that mutations are not as random as scientists once thought. The transposons can either cut and paste themselves.
a) The “savannah hypothesis” revolves around the idea that the migration from forests to the savannah evolved our species from apelike creatures to the humans we are today. It begins with the idea that an environmental change forced humans to leave the forests for the open fields of the savannah. Since food was harder to find in the savannah, our ancestors began to hunt other animals and the need to travel longer distances to find animals forced them to walk on two feet.