... microevolution is within-species evolution of genes. There are various kinds of dynamics of macroevolution. Punctuated equilibrium theory proposes that once species have originated, and adapted to the new ecological niches in which they find themselves, they tend to stay pretty much as they are for the rest of their existence. Phyletic gradualism suggests that species continue to adapt to new challenges over the course of their history. Species selection and species sorting theories claim that there are macroevolutionary processes going on that make it more or less likely that certain species will exist for very long before becoming extinct, in a kind of paralle ...
... Sahara-like dunes were part of an enormous desert that once extended north into Montana. During the last ten years, a number of studies on modern and ancient sand seas, or ergs, have increased greatly our understanding of eolian bedform dynamics. Additionally, we can describe trace fossils in the Coconino and relate them to the physical environments of deposition. This provides us with more comprehensive reconstruction of the erg environments. Although the cliff-forming nature of the formation can present certain logical problems, the exceptional three-dimensional exposures in the Grand Canyon give the sedimentologist and ichnologist the opportunity to examine th ...
... cancer and eventually death to those exposed to high levels of radiation. Even the government declared that nuclear powers were safe and efficient. The truth is that accidents do happen at nuclear power plants and at other facilities all the time. An accident at a nuclear power plant has the potential to be much more harmful than an accident at a coal or gas plant because of the radiation that could be released. An example of this is Three Mile Island in Pennsylvania where there was a partial core meltdown in march of 1979 caused large amounts of radiation to be released into the atmosphere. Accidents involving US nuclear power plants are very rare. Thi ...
... the functions listed in the previous statements. Also, the provides an opportunity to define an organization and display it to everyone to see. Furthermore, is not a new product that has just been recently introduced in the market. However, it just has not been widely used until the past few years. People use everyday without knowing that they are using it. , therefore, is the client/server, PC, Unix, Apple and many other applications that one has been using on his/her work. Security on the Internet is just as hazardous as the . Any leakage of information through the transmission of data is possible. Most, the and the Internet shares a common purpose, that is, ...
... means improvement in water quality. Monitoring on a national level showed that large investments in point-source pollution control have yielded no statistically significant pattern of improvement in dissolved oxygen levels in water in the last 15 years. It may be that we are only keeping up with the amount of pollution we are producing. (Knopman, 1993) The early biosphere was not pleasant for life because the atmosphere had low levels of oxygen. Photosynthetic bacteria consumed carbon dioxide and produced simple sugars and oxygen which created the oxygen abundant atmosphere in which more advanced life forms could develop. (Brown, 1994) The mystery of ...
... have improved, they often stop taking the drug. Just because the symptoms have disappeared it does not mean the disease has gone away. Prescribed drugs should be taken until all the medicine is gone so the disease is completely finished. If it is not, then this will just give the bacteria some time to find a way to avoid the effects of the drug. One antibiotic that will always have a long lasting effect in history is penicillin. This was the first antibiotic ever to be discovered. Alexander Fleming was the person responsible for the discovery in 1928. In his laboratory, he noticed that in some of his bacteria colonies, that he was growing, were some clear spo ...
... dangers. If they are so dangerous then why do doctors prescribe them? Why do pharmacies all over the planet still make them and sell them? To have an opinion on whether steroids are safe are not, it would help to know how they work and what responsibilities are needed when choosing to take them. are a synthetic for of the naturally occurring hormone, testosterone. are used to promote accelerated muscle hypertrophy in both males and females. Hypertrophy describes the increase in size of muscle as the result of stress put upon the muscle. Muscles go through hypertrophy in order to adapt to the increased demands placed upon them to perform. This is the p ...
... for the world because of it. Some of scientist ideals of how to alter this new science to create the perfect human does in-fact sound crazy. But if was regulated to prevent such things the new science could bring wonders to many peoples lives. The first form of began with a man named Mendel, a monk in the late nineteenth century. He was the first to even formulate the concept of the gene from his experiments on pea plants. Since Mendel, other scientists have continued in agricultural engineering, a type of engineering that deals with the cross breeding of plants and cattle to maximize their productivity. Through time geneticists have continued to find bette ...
... region of the brain. The working hypothesis shared by most investigators is that schizophrenia is a disease of neural connectivity caused by multiple factors that affect brain development. (3,4,5) Our current model of the causation of schizophrenia is very similar to that used to understand cancer. That is, schizophrenia probably occurs as a consequence of multiple "hits," which include some combination of inherited genetic factors and external, nongenetic factors that affect the regulation and expression of genes governing brain function or that injure the brain directly. Some people may have a genetic predisposition that requires a convergence of additional ...
... the house. Day's five through eight were designed to truly concentrate on implementing the developed program with the same number of opportunities to escape as the previous four days. RESULTS It was determined that the subject would almost always attempt to escape from the house when it was given the opportunity during the first four days. As the days progressed, it's total number of escapes decreased. This could be attributed to the fact that every time it found it's way outside, it was immediately picked up and returned to it's proper location. This is a perfect example of using the untraining technique of "negative reinforcement". Even thought the inte ...
