Reference no: EM131734523

3 posts to answer are attached. JUST A PARAGRAPH for each -- NO cover page etc. Minimum 100 words each post

ask a question to the person IN EACH post.

POST 1:

ANSWER THIS: Human Immunodeficiency Virus (HIV) is one of the most deadly diseases that plague humans today. Although the origin of HIV is still contested in many scientific circles, one thing is certain, the virus has an evolutionary rate that is unprecedented. Evolutionary rate can be described as the speed in which an organism reproduces and introduces new variations of genetic code.

When you discuss the evolutionary rate of humans you are talking about genetic variations taking centuries to develop and be introduced. When we discuss the evolutionary rate of HIV however, we begin to see genetic variations being introduced in a matter of sometimes weeks.

HIV's knack to evolve so quickly can be attributed to a few things. The first is the simplicity of its chemical structure. It is basically an enzyme and RNA molecules. RNA is what HIV uses to reproduce. When an HIV finds a suitable cell to become its host it invades the cell and copies its RNA onto the host cell's DNA.

When this process is successful the host cell will begin to create more copies of itself using the genetic code provided by the HIV's RNA. At the same time this is happening random mutations of HIV are being rapidly reproduced.

The second cause for HIV's rapid evolution is when an infected person begins to be treated for HIV. When you have many variations of the HIV cell you have some that are effected by antiviral medication and some that are immune. The cells that are immune begin to thrive in the environment created by the medication and then that strand of HIV is produced more rapidly.

Without an understanding of evolution, when doctors are treating those infected by HIV they would have no explanation as to why the medicine is not working and therefore hit a road block. Unlocking more of the secrets of evolution will be the key to defeating this terrible disease.

POST 2:

ANSWER THIS: In response to the question, "If adaptation improves a specie's success, why do species go extinct instead of adapting and surviving," it is important to understand what drives adaptation. Adaptation is not something that can be willed into existence or honed over time by an organism.

It is not uni-linear and has no set direction or end state. It occurs mostly in response to the environment of the organism. Within a species, there can be different traits that are favorable to the conditions of the environment, which allow the organism to continue its existence. In the example of the giraffe, the length of the neck varied among the population. The giraffes with long necks were able to reach food in higher places.

Giraffes with shorter necks were probably unable to feed as often and died off out of starvation. The long necks were able to stay nourished and continued to reproduce, thus continuing the success of the species with the specific trait of having a long neck.

In the instance with the giraffe, it shows the organism evolved in response to the environment it lived in. There can also be a presence of a genetic mutation that happens with in the genes of a species. These mutations can sometimes be in favor of the environment, ensuring the continuation of the species existence.

The mutation is passed along through a new line and each generation that posses the new trait go on, while the original line dies off for lack of ability to overcome environmental challenges. For example, a species of snakes may spontaneously create a genetic mutation that changes the color pattern of its skin, causing it to become more camouflaged with its environment. This is favorable to its survival. Other snakes without this new trait die off. The mutation is carried on through future generations.

In the end, there are sporadic changes that happen within the genealogy of a species that help it adapt to its environment. These changes are inherited by offspring and continue until another change happens. Nothing decides when or if this will happen amongst any group. And the group cannot bring about this change intentionally

POST 3:

ANSWER THIS: This week in our reading we learned that the process of adaptation and evolution are not a quick thing nor is it something that is really able to be controlled.

Adaptation does help improve a species way of life but the amount of time that it has taken what ever species to make that adaptation means that the actual habitat that they were living in could have changed another two to three times.

So while they were adapting to one environment change two to three more could have happened simultaneously and now they are back to square one.

Just because an animal has the ability to adapt does not always mean it is going to be for the best with the way that our climates changes now days and growing population of humans this almost makes it nearly impossible for anything to survive and have the time needed to adapt to all the things that are constantly changing around them and in the environment. I don't think its a question of is said species going to become extinct at this point in time I think its more of a question of when will they go extinct.