Analogous Structures in Evolution

There are many types of evidence supporting evolution, including studies in the molecular biology field, such as DNA, and in the developmental biology field. However, the most commonly used types of evidence for evolution are anatomical comparisons between species. While homologous structures show how similar species have changed from their ancient ancestors, analogous structures show how different species have evolved to become more similar. Speciation Speciation is the change over time of one species into a new species. Why would different species become more similar? Usually, the cause of convergent evolution is similar selection pressures in the environment. In other words, the environments in which the two different species live are similar and those species need to fill the same niche in different areas around the world. Since natural selection works the same way in these environments, the same types of adaptations are favorable, and individuals with favorable adaptations survive long enough to pass down their genes to their offspring. This continues until only individuals with favorable adaptations are left in the population. Sometimes, these types of adaptations can change the structure of the individual. Body parts can be gained, lost, or rearranged depending on whether their function is the same as the original function of that part. This can lead to analogous structures in different species that occupy the same type of niche and environment in different locations. Taxonomy When Carolus Linnaeus first began classifying and naming species with taxonomy, the science of classification, he often grouped similar-looking species into similar groups. This led to incorrect groupings compared to evolutionary origins of the species. Just because species look or behave the same doesnt mean they are closely related. Analogous structures dont have to share the same evolutionary path. One analogous structure might have come into existence long ago, while the analogous match on another species may be relatively new. They may go through different developmental and functional stages before they are fully alike. Analogous structures are not necessarily evidence that two species came from a common ancestor. It is more likely they came from two separate branches of the phylogenetic tree and may not be closely related at all. Examples The human eye is very similar in structure to the eye of the octopus. In fact, the octopus eye is superior to the humans in that it doesnt have a blind spot. Structurally, that is the only difference between the eyes. However, the octopus and the human are not closely related and reside far from each other on the phylogenetic tree of life. Wings are a popular adaptation for many animals. Bats, birds, insects, and pterosaurs all had wings. But a bat is more closely related to a human than to a bird or an insect based on homologous structures. Even though all these species have wings and can fly, they are very different in other ways. They just happen to fill the flying niche in their locations. Sharks and dolphins look very similar due to color, placement of their fins, and overall body shape. However, sharks are fish and dolphins are mammals. This means that dolphins are more closely related to rats than they are sharks on the evolutionary scale. Other types of evolutionary evidence, such as DNA similarities, have proved this. It takes more than appearance to determine which species are closely related and which have evolved from different ancestors to become more similar through their analogous structures. However, analogous structures themselves are evidence for the theory of natural selection and the accumulation of adaptations over time.

Nuclear Weapons And Its Impact On The World - 1702 Words

Throughout history many progressions in science and technology have set us ahead of other nations both scientifically and militarily. The use of new technology to set us ahead of other nations was imminent. With the creation of planes and tanks in the First World War the advancement of new technology and nation destroying weapons were not far off. With the threat of the Germans creating Wonder Weapons which could win them the war and the world we enlisted the help of defected German scientists and Americas greatest minds scientifically and military alike. With the fear of losing hundreds of thousands of troops in japan we used the first atomic bombs setting a new world standard for warfare and changing the way our nation was viewed. The†¦show more content†¦Albert Einstein who escaped Nazi Germany and Enrico Fermi who escaped fascist Italy these two who defected to the United States informed the president of the power the Axis nations were working on. With Einstein pushing P resident Roosevelt to research this power from splitting uranium atoms and the President seeing no use for this he slowly started agreeing. In 1942 the Manhattan Project group is created with the idea to make the world’s first Atomic Bomb (Sherrow page 6; â€Å"The Manhattan Project† Web). The Project was held at first out of only a few colleges, Columbia University, University of Chicago, and the University of California at Berkeley. The same year that the project was established the first controlled nuclear reaction was achieved by Fermi and the S-1 group at the University of Chicago. With this success more funds were placed into the project and development of the bomb. Nuclear facilities were built at Oak Ridge, Tennessee and Hanford, Washington. The main station and bomb building plant was placed in Los Alamos, Texas with Robert Oppenheimer as the head. The main Power source for the bomb is Uranium-235 and that that its isotope would work as a fuel source for a nuclear device. The process though of separating Uranium-235 and Uranium-238 would prove very difficult but necessary to gain access to the fuel source (Sherrow page 7; â€Å"The Manhattan

Better Education for the Smaller Family Free Essays

In recent years, a trend around the world has been toward a smaller family. Most families in the world have one or two children. In Vietnam, the average number of children per family has decreased in the last 20 years. We will write a custom essay sample on Better Education for the Smaller Family or any similar topic only for you Order Now A typical Vietnamese family has only one or two children. In the past, a family with more than ten children was not strange. The better education and the improvement of living condition have caused smaller family size. First, the average number of children per family has decreased because of better education. After the Vietnam War, the Vietnamese government has emphasized on education. Every kid could go to school to study. Therefore, more knowledge and more job opportunities have provided to Vietnamese people. High-educated people concentrate on their work and their income. They do not want to marry soon. The more late married couples there are, the fewer children are born. Consequently, the family size has decreased. Moreover, Vietnamese people used to think that a big family with many children is a happy family. The educated people have a different point of view. They cannot provide their children a good education and a satisfactory support if they had many children. They have realized the benefit from a smaller family. For instance, the parent can afford $1000 to their children a month. If they had four children, each would receive only $250. However, the kid in a single child family would receive the whole supply. A small family would provide the child a good condition to grow up. Besides, a problem has occurred from smaller families. The child becomes mischievous and naughty. The kid does whatever he or she wants because they know that their parent do not have many children. Second, the improvement of living condition has caused smaller family size. During the Vietnam War, Vietnamese people liked to have many children because they were afraid that they would lose their kids for the war. They wanted more and more of their kids to become more and more Vietnamese soldiers. After the war, they did not need more children. As a result, the family size started to decrease. Furthermore, Vietnam is a country base on farm product. Eighty percent of Vietnamese people are farmers. The farm work is very difficult and requires a lot of labor. They needed many family members to help their work. Therefore, they had many children. Nowadays, farmers have used machine and new technology in their work. The apparatus has replaced the labor. The farmers do not need many people to help them. Accordingly, they have had fewer children. In addition, more public services and information have been provided to Vietnamese people. The couples have planed to have healthy marriages. A small family is a good choice for them. This smaller, healthier family contributes to overall development and slower population growth. Nevertheless, the trend toward smaller family needs to be controlled in order to have a best result. Providing jobs and food is hard, but lacking work force is also a problem. Nowadays, people have fewer children then they had before. The more kids they have, the more money and time they spend. In order to have a happy family, they have to support a good environment to their children. Separating the parents† afford and love for three or four children is not a good idea. Consequently, a smaller family is the best choice. How to cite Better Education for the Smaller Family, Papers

How do you feel about photographs assignment Essay Example For Students

How do you feel about photographs assignment Essay How do you feel about photographs? Are you the type person that thinks a picture is worth a thousand words? If those statements describe you, you should probably take another look at how much weight and value that you give a photograph because pictures are very easily misinterpreted. When you take a minute to stop and think about pictures how they are looked at you might notice that more often than not if there is no writing with it you can only guess at what it shows. On the multiple occasions that we have looked at photos in class most people have eventually come to the same conclusion as Berger does in his essay. There are several core beliefs that Berger talks about and I will discuss in this paper. During the time that we spent looking and commenting on photographs during class you may have experienced the things that he describes. A photograph arrests the flow of time in which the event photographed once existed. All photographs are of the past, yet in them an instant of the past is arrested so that, unlike a lived past, it can never lead to the present. Every photograph presents us with two messages: a message concerning the event photographed and another concerning a shock of discontinuity. (1) This is what Berger said about a photograph and what it is able to capture. What he means by this is that a picture captures everything that is happening at a given time. The shock of discontinuity refers to anything that is out of order at the time the picture is taken. Because people are not always ready for pictures to be taken or even in a picture that is posed for the background may be out of order things can sometimes seems odd or out of place in a photograph. In my experience the parts of a photograph that are not planned can end up being what people find the most interesting or that they use to interpret the meaning of the image. The little unplanned things the occur in the backgrounds of photographs are many times what grabs peoples attention or at least affect in some way what they feel about it. In my pictures the subject is in his room which happens to have a lot of posters of women on the wall so some people thought that this meant that he was a horny guy which was not the image I was trying to convey at all. Im sure everyone has had this type of thing happen to them at some point. So I would think that everybody agrees with this statement. Another one of Bergers opinions is, A photograph preserves a moment of time and prevents it being effaced by the suppression of further moments. In this respect photographs might be compared to images stored in the memory. Yet there is a fundamental difference: whereas remembered images are the residue of continuous experience, a photograph isolates the appearances of a disconnected meaning.(1) This means that in a memory you know exactly what is going on. It is something that happened to you or explained to you in a way that you are able to know exactly what happened and how it should be interpreted. This allows a person to know how a memory should be viewed. However a photograph cannot clearly let you know its meaning unless you are the person who took it. The reason for this is that a photograph is just a picture of a moment in time that is open for the views of each individual who sees it. The photo has a meaning originally but it is not directly connected to it. So all the picture has is an appearance of some unknown meaning. .u9508fdc2773cebb52114ee80a39418ae , .u9508fdc2773cebb52114ee80a39418ae .postImageUrl , .u9508fdc2773cebb52114ee80a39418ae .centered-text-area { min-height: 80px; position: relative; } .u9508fdc2773cebb52114ee80a39418ae , .u9508fdc2773cebb52114ee80a39418ae:hover , .u9508fdc2773cebb52114ee80a39418ae:visited , .u9508fdc2773cebb52114ee80a39418ae:active { border:0!important; } .u9508fdc2773cebb52114ee80a39418ae .clearfix:after { content: ""; display: table; clear: both; } .u9508fdc2773cebb52114ee80a39418ae { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u9508fdc2773cebb52114ee80a39418ae:active , .u9508fdc2773cebb52114ee80a39418ae:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u9508fdc2773cebb52114ee80a39418ae .centered-text-area { width: 100%; position: relative ; } .u9508fdc2773cebb52114ee80a39418ae .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u9508fdc2773cebb52114ee80a39418ae .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u9508fdc2773cebb52114ee80a39418ae .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u9508fdc2773cebb52114ee80a39418ae:hover .ctaButton { background-color: #34495E!important; } .u9508fdc2773cebb52114ee80a39418ae .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u9508fdc2773cebb52114ee80a39418ae .u9508fdc2773cebb52114ee80a39418ae-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u9508fdc2773cebb52114ee80a39418ae:after { content: ""; display: block; clear: both; } READ: Famous photographers: Jerry Uelsmann, Freeman Patterson, and Annie Slivovitz EssayA good personal example of this is a picture of my subject in a car because my memory was of his crazy driving but all anyone got from the picture was that he liked cars. So the memory would have been a much better way to get my message across people didnt know the story behind the picture. The final statement that Berger makes is, In itself the photograph cannot lie, but, by the same token, it cannot tell the truth; or rather the truth it does tell, the truth it can by itself defend, is a limited one.(1) This basically wraps up everything that he has said before. Pictures are limited in what they can tell you, they can provide some of a story but not all of it. If a photograph is misinterpreted it is not its fault because it cannot be expected for a picture to tell you everything about the scene it represents. A picture in union with a memory can be a great way to get a point across but on its own a picture is not comprehensive enough to tell a story. Such as the picture I took of the cars speedometer. If you look at and say oh its only at sixty, you may think hes a fairly safe driver. What you wouldnt know is that he was going sixty on a winding back road at night. So even though the picture didnt lie the viewer was just unable to tell the whole truth from looking at it. Based on my experience I agree with Berger that photographs are nice but they are too open to be considered truth. The memory that I wrote tells much more about the person than the photographs. Some people get the right idea from the pictures but overall the memory did a lot better job of conveying the message I wanted to send about the subject.