The Origin Of Life Essays - Origin Of Life, Astrobiology

The Origin Of Life The origin of Life There are many theories where life came from, but none of them is proven to be the right one. The obvious theory that life originated on earth is not accepted by everyone. One reason of disbelief in this theory that life originated on earth is a lack of time. It was an early belief that life originated through a slow and long process (many scientists do not share this belief though), probably too short and too long for the time life had on our planet. Life must have been formed within a period of approximately 200 million years. If we represent the whole Christian era - two thousand years - by one inch, the time available for the emergence of life could measure as much as 1.5 miles. Another theory called panspermia claims that life was created somewhere else, not on earth, and traveled to our planet via meteorites or comets. Another version of panspermia claimed by Francis Crick and Leslie Orgel is that life was brought to earth by a spaceship sent by a more intellectual species. Thi s theory is called directed panspermia. The last theory might be the least likely one, since there is no actual evidence for spaceships or species from other planets. The panspermia theory can not be disproved and it might be possible that life came to earth via a comet. Bodies like comets contain organic molecules which are similar to the molecules of living organisms, but most scientists say that reactions creating these molecules take place out there. We can not find an answer for this question since neither theory can totally be proven. Supporters of the panspermia theory say that there was not enough time for life to originate. Supporters of the theory that life originated on earth can not prove that life did not come from outer space. The Christian theory that life was created by God is abstract and will not be discussed further in this paper. Personally I believe in the theory that life was born on earth. Six elements are needed to create life. Almost every organic matter can be summarized symbolically in these six different elements: carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S). One also says that life can be explained by the formula CHNOPS. These are the main characters in the creation of life chemically. Knowing that these six elements are needed to create life we have to find out in what condition these elements were. It is still not known what the composition of the primitive atmosphere was. It was believed that the atmosphere consisted of hydrogen (H2), methane (CH4), ammonia (NH3), and water vapor (H2O). But this is doubted today. Scientists say that carbon probably was not present in the combination with hydrogen (methane). It probably was present in the combination with oxygen, mostly with carbon dioxide, or CO2. In the early years of the earth, about 4 billion years ago, there was no oxygen in the atmosphere of the world. There needs to be life in order to have free oxygen. What was the temperature on earth in these days? It is practically impossible to find the answer to this question, but it is an important issue to know since temperature limits the life span of biomolecules, such as proteins, nucleic acids, and the blocks they were contained in. Thinking of this fact chemists assume that the temperature of the environment might have been very cold, possibly under the freezing point. Geochemists, though, do not think this way. They believe that temperature might have been close to the boiling point of water, but they also believe that there must have been a high atmospheric pressure, which kept the oceans from boiling. What was the sun like? Four billion years ago the sun was cooler than today. It sent out probably 25% less energy to the Earth than today. But this was probably offset by the greenhouse effect of atmospheric carbon dioxide. There definitely was a lot of water in the beginning of life. Water is the vital element of any living organism. The atmosphere above the water was heavy with carbon dioxide, nitrogen, hydrogen

Mount Sandel - Mesolithic Settlement in Ireland

Mount Sandel - Mesolithic Settlement in Ireland Mount Sandel lies on a high bluff overlooking the River Bann and it is the remains of a small collection of huts provide evidence of the first people who lived in what is now Ireland. The County Derry site of Mount Sandel is named for its Iron Age fort site, believed by some to be Kill Santain or Kilsandel, famous in Irish history as the residence of the marauding Norman king John de Courcy in the 12th century AD. But the small archaeological site east of the remains of the fort is of far greater importance to the prehistory of western Europe. The Mesolithic site at Mount Sandel was excavated during the 1970s by Peter Woodman of University College Cork. Woodman found evidence of up to seven structures, at least four of which may represent rebuildings. Six of the structures are circular huts of six meters (about 19 feet) across, with a central interior hearth. The seventh structure is smaller, only three meters in diameter (about six feet), with an exterior hearth. The huts were made of bent sapling, inserted into the ground in a circle, and then covered over, probably with deer hide. Dates and Site Assemblage Radiocarbon dates at the site indicate that Mount Sandel is among the earliest human occupations in Ireland, first occupied around 7000 BC. Stone tools recovered from the site include a huge variety of microliths, which as you can tell from the word, are tiny stone flakes and tools. Tools found at the site include flint axes, needles, scalene triangle-shaped microliths, pick-like tools, backed blades, and a few hide scrapers. Although preservation at the site was not very good, one hearth included some bone fragments and hazelnuts. A series of marks on the ground are interpreted as a fish-drying rack, and other diet items may have been eel, mackerel, red deer, game birds, wild pig, shellfish, and an occasional seal. The site may have been occupied year-round, but if so, the settlement was tiny, including no more than fifteen people at a time, which is quite small for a group subsisting on hunting and gathering. By 6000 BC, Mount Sandel was abandoned to the later generations. Red Deer and the Mesolithic in Ireland Irish Mesolithic specialist Michael Kimball (University of Maine at Machias) writes: Recent research (1997) suggests that red deer may not have been present in Ireland until the Neolithic (earliest solid evidence dates to around 4000 bp). This is significant because it implies that the largest terrestrial mammal available for exploitation during Irelands Mesolithic may have been the wild pig. This is a very different resource pattern than that which characterizes most of Mesolithic Europe, including Irelands next door neighbor, Britain (which was chock full of deer, e.g., Star Carr, etc.). One other point unlike Britain and the Continent, Ireland has NO Paleolithic (at least none has yet been discovered). This means that the Early Mesolithic as seen via Mt. Sandel likely represents Irelands first human inhabitants. If the pre-Clovis folks are right, North America was discovered before Ireland! Sources Cunliffe, Barry. 1998. Prehistoric Europe: An Illustrated History. Oxford University Press, Oxford.Flanagan, Laurence. 1998. Ancient Ireland: Life before the Celts. St. Martins Press, New York.Woodman, Peter. 1986. Why not an Irish Upper Paleolithic? Studies in the Upper Paleolithic of Britain and Northwest Europe. British Archaeological Reports, International Series 296:43-54.

Creative writing - 'Otherness' Essay Example | Topics and Well Written Essays - 1500 words

Creative writing - 'Otherness' - Essay Example I looked at her stern eyes and said, "he keeps it in the case that he carries with him to shop every day." Laila jo said nothing as tears dropped down her cheek. She knew like me, this was not the life she deserved but she didnt ask me about the plan any further. That night as we sat to eat our dinner, Laila did not speak at all. Rasheed went with his own narration of the days event, listened to the radio and went to sleep. I felt the chill in the air and my eyes refused to rest. I was feeling immensely alert and with every gunshot outside, I became all the more vigilant. Suddenly, I heard a thud and a cry and rushed upstairs. As a climbed the stairs, thousand thoughts crossed my mind but the sight of blood numbed me once and for all. Lying on the pool of blood was Laila jo...Rasheed had the gun in his hand. Aziza was crying her lungs out sitting by the side of her mother. I rushed to Laila jo and found blood oozing from her throat. Her eyes were wide open and for a fraction of a second I thought she was alive. I cursed myself for hatching that plan to her. I should not have confided to her. This was all due to me. A harami by birth, I deserve all the pain I suffer, But Laila jo? She was not a harami? At such a tender age she suffered so much! I should have killed Rasheed myself! o Allah! why is it that you take away everything that is dear to me! what have I done to be punished so hard! Rasheeds constant blows on my back felt nothing compared to the pain I was feeling in my heart. He was trying to separate me from my child but I will not let him have his will. I would not leave my child, she needed me. But a distant cry reminded me of the girl I had orphaned. Aziza I am your culprit! I am to be blamed for all that you would suffer in your life! My heart felt heavy and the throat sore. The sound of Laila jos voice was ringing continuously in my head. Aziza climbed down from the bed and sat by my side holding her