Dinosaur Extinction Essays (Examples)

Dinosaurs: arm-Blooded?

There is presently much controversy regarding the issue of dinosaurs, as the fact that experts have access to a limited amount of resources concerning this matter makes it difficult for them to express certainties concerning this particular animal reign. Even with the fact that there are presently no living dinosaurs to be dissected, scientists have come up with a series of theories based on how dinosaurs behaved. In spite of their physiology, most dinosaurs put across behavior characteristic to mammals and birds. One of the oldest debates in the history of dinosaur studies is related to the blood temperatures of these creatures, as some experts insist that they were cold-blooded while others maintain that they were warm-blooded. The presence of dinosaur fossils at high altitudes makes it possible for one to consider that dinosaurs were warm-blooded, taking into account that cold-blooded creatures typically evolve in warm areas.

All…

Works cited:

Misiroglu, Gina, "The Handy Answer Book for Kids (and Parents)," (Visible Ink Press, 2009)

Norell, Mark; Gaffney, Eugene S.; and Dingus, Lowell, "Discovering dinosaurs: evolution, extinction, and the lessons of prehistory," (University of California Press, 2000)

Norman, David, "Dinosaurs: a very short introduction," (Oxford University Press, 2005).

Dinosaurs are a popular topic with young students of both genders and all ethnicities. Because they are extinct, dinosaurs generally take on a mythic character among children of this age; furthermore, because they are physically enormous and dominant, most students find them fascinating as almost fantasy creatures. Therefore, creating a thematic unit on dinosaurs for first and second graders was fun and rewarding. With the plethora of material available on the subject, tailoring a unit for my students also involved a thorough review of films, books, websites, and CD ROMs. I relied heavily on multimedia materials, as dinosaurs' main impact for students is visual and aural. I employed Internet and CD Rom sources in addition to picture books and a brief cartoon film. These visual tools proved engaging for most students, who would otherwise become bored with pure fact and data. I based the success of the lesson on the…

Deposition occurred over a very long time period. The study found that the sediments separating the two events were characteristic of normal sedimentation, with burrows formed by creatures colonizing the ocean floor, erosion and transportation of sediments, and no evidence of structural disturbance" which means that there is no reason to believe that the asteroid impacted normal life in measurable fashion very quickly, or that fossil evidence of the asteroid's impact had been disrupted (New blow against dinosaur-killing asteroid theory, geologists find, 2009, National Science Foundation).

Even defenders of the asteroid theory think it is unlikely that it was a one-time event that killed most of the life on planet earth, and believe that the asteroids created inhospitable conditions that developed over time. Recent research also indicates that the asteroid "landed in deeper water than previously assumed and therefore released about 6.5 times more water vapor into the atmosphere. The…

Works Cited

Geologist gets to the bottom of Chicxulub impact crater. (2007, January 22).

University of Alaska Fairbanks. ScienceDaily. Retrieved May 3, 2009, from  http://www.sciencedaily.com ? / releases/2007/01/070118094039.htm

Hypothesis: Asteroid impact. (2009). Evolution: What killed the dinosaurs? PBS.

Retrieved May 3, 2009 at  http://www.pbs.org/wgbh/evolution/extinction/dinosaurs/asteroid.html

..the giant salamander, 2010, Cryptozooscity).

There are fears that giant salamanders may meet the same fate as dinosaurs, given that modern life has exposed them to quick-moving, larger-brained humans who consider them a delicacy and will hunt them with greater determination than previous predators. The amphibian's size makes them "lucrative prey for hunters, who can sell the flesh for around U.S.$100 per kg (£30 per lb)," a considerable sum when one salamander can grow to over one hundred pounds (Black 2005). "They are protected species; but in China, illegal hunting is bringing them within sight of extinction" (Black 2005). Observed one conservationist: "They are easy to catch, hiding in rock crevasses during the day, and people know where to find them" (Black 2005).

The loss of these giant relics would not merely be a loss of a link to human evolutionary history of the past: the salamanders may also provide…

References

Black, Richard. (2005, September 19). Hunting threat to big amphibians. BBC News. Retrieved July 27, 2010 at  http://news.bbc.co.uk/2/hi/science/nature/4259596.stm 

Giant salamanders may help scientists fight extinction threat. (2010, July 21). CNN. Retrieved

July 27, 2010 at  http://www.latimes.com/sns-giant-salamander,0,3628440.story 

The living fossil...the giant salamander (2010, February). Cryptozooscity. Retrieved July 27, 2010 at  http://cryptozoo-oscity.blogspot.com/2010/02/living-fossilthe-giant-salamander.html

However, there simply does not seem to be sufficient evidence for the disease hypothesis. First, there has been no evidence of disease found. Next, even extremely virulent diseases, like the plague or West Nile Virus, do not have the kill rates necessary to cause the extinction of an entire species. In addition, one has to realize that the extinction of large mammals coincided with the extinction of other animals, like birds, marsupials, placentals, testudines, and crocodilians. It is unlikely that a disease would be lethal in such a wide-variety of animal populations, especially when it did not destroy all species of certain animal genus.

The final theory is that a meteor killed the large mammals. There is evidence that meteor impacts caused earlier extinctions like the Permian-Triassic extinction and the extinction of the dinosaurs. Meteor impacts can interfere with food sources, because the resulting dust in the air interferes with…

Without the mass extinction of the dinosaurs, is doubtful that human beings would ever have evolved in the first place. By comparison to the effects of the that meteorite, all of the human activity in the world that has ever occurred since the first human being who hunted for prey or started a fire is infinitesimally small and utterly insignificant.

More importantly, human concern for animal species extinctions seems to be largely predicated on our anthropomorphic impulses: that is, we have the greatest empathy for animals that remind us of ourselves or that seem appealing or "cute" to us. Consider the different way that we regard tuna and dolphin for just one example. We hunt the former so aggressively that we are on the verge of having to maintain wild tuna populations artificially if we hope to continue eating as much sushi and tuna fish sandwiches as we wish. Other…

He describes how wild grains and animals were domesticated, as well as the new technologies that made farming possible (sickles, baskets, pestles, gourds, irrigation, the wheel, the plow). He uses a chart to plot these movements. His evidence is mainly archeological, historical, and botanical with heavy doses of appeal to imaginary scenarios. Its power to convince is narrational. His ultimate point in cataloguing this change is to assert how, for first time in history, humans become a prime factor in altering earth's natural landscapes. Land was now exploited and degraded through deforestation for crops and soil erosion.

Summary: Ruddiman summarizes the history of how humans began to shape the earth through technology and landscape transformation. He relies on the credibility of his narrative.

Ch. 8, pp. 76-83: His main claim is that humans rather than nature have created a rise in atmospheric methane. He presents several lines of argument, beginning…

From the point-of-view of the variation and flexibility of the species such cultivated woody crops rank as no more than cornfields. While the tree farms are conveniently be stretched on the private lands, national forests those are considered priceless reservoirs of most of the biological diversity of the nation cannot expand so easily. The commercial logging is considered as the greatest danger for survival of the national forest system. The timber sales are growingly concealed beneath the post fire recovery and fire prevention missions, forest health initiatives and restoration programs. (Endangered Forests: Endangered Freedoms)

Wetlands disappearing

Declining wetlands and reservoir construction are having spectacular influences on a global scale. (the Importance of Wetlands and the Impacts of eservoir Development) the data of USF & WS reveals that the United States added 2.3 million acres in ponds and inland mudflats during the period of mid 1950s and mid1970s. The country added…

References

Acid Rain -- a Contemporary World Problem. Retrieved at http://www.geocities.com/narilily/acidrain.html. Accessed on 3 February, 2005

Acid Rain: Do you need to start wearing a rain hat? Retrieved at  http://ga.water.usgs.gov/edu/acidrain.html . Accessed on 3 February, 2005

Barney, Gerald O. The Whole World in Our Hands. SF Chronicle. 31 December, 2000. Retrieved at http://www.mindfully.org/Sustainability/in-Our-Hands.htm. Accessed on 3 February, 2005

Bryant, Peter J. Biodiversity and Conservation: A Hypertext Book. Retrieved at http://darwin.bio.uci.edu/~sustain/bio65/lec05/b65lec05.htm. Accessed on 3 February, 2005

Furthermore, he argues, a technological culture is not an inevitable feature of human evolution. If other cultures had achieved ascendancy, then science and technology would not have emerged as a reference point for measuring intelligence. SETI's requirement for an almost identical technology, although scientifically understandable, is based on an impoverished concept of intelligence.

According to Munevar, the development of a scientific culture, with access to radio communication, is highly contingent, requiring a number of lucky breaks from the environment and human natural and social history. In this context Munevar cites the development of mammalian intelligence. It is widely believed that the dinosaurs were wiped out by the immediate effects of an asteroid or cometary impact or possibly volcanic eruption. But mammals who survived the years of darkness caused by the dust of the impact or eruption then evolved to occupy the niche held by the dinosaurs. If the dinosaurs had…

Works Cited

Lamb, D. Discovery, Creativity and Problem Solving, Aldershot: Ashgate. 1991

Lamb, D. Crop patterns and the greening of Ufology, Explorations in Knowledge, XI, 2: 12-46. 1994

Munevar, G. Radical Knowledge, Aldershot: Avebury. 1981

Munevar, G. Extraterrestrial and human science, Explorations in Knowledge, VI, 2: 1-8. 2005

components to the principle of uniformitarianism: the first is that the principles that can be applied to the Universe nowadays have always been applicable in the same manner. The second implies that these principles occur and are applicable everywhere in the Universe. With this in mind, if occasional catastrophic events such as the ones described have occurred in the past on Earth, they could occur again, in a similar manner, today or in the future. So, if the dinosaurs became extinct following a meteorite impact, another such impact could hit the Earth in a similar manner, leading to another large scale extinction.

Geologic processes include diverse ways in which the Earth's surface is modeled. These include soil erosion or desertification. If an area has been significantly eroded, this could lead to devastating floods. At the same time, other geologic processes can lead to tsunamis. As a consequence, it is obvious…

But the supply far outstrips demand, Europeans are finding. The climate of this marketplace itself is decidedly cloudy. Advance prices have plunged by half.

At this point, one shouldn't portray it as a liquid, vibrant market," said Atle C. Christiansen of PointCarbon, a Norway-based research firm (Climate, 2004).

More than six years after governments negotiated the historic climate accord in Kyoto, Japan, the world is taking only halting steps _ not always forward, never in unison _ to follow through (Climate, 2004).

In fact, the Kyoto treaty itself is not yet in force, since it hasn't been ratified, as required, by industrial countries emitting a total of 55% of "greenhouse gases," such as carbon dioxide, that trap heat in the atmosphere that Earth otherwise would give off.

ussia's expected accession later this year would clear the 55% hurdle. But even a functioning Kyoto agreement would have little impact: Its limited…

References

Amazon rainforest destruction at 10-year high

By Raymond Colitt in Sao Paulo (accessed 5-19-05)

Published: May 20, 2005 03:00 | Last updated: May 20, 2005 03:00

 http://news.ft.com/cms/s/4ea07b74-c8cd-11d9-87c9-00000e2511c8.html  rainforest (accessed 5-19-05)

TED Talks

Ideas worth Spreading

Nina Jablonski breaks the illusion of skin color (TED2009, 2009)

Nina Joblonski opens by commenting on Darwin's pigmentation and his upbringing. She further speaks of his voyage on the Beagle and his interest in the pigmentation of humans. Darwin did not believe that there was any correlation to skin pigmentation and climate. However, Joblonski points out that if Darwin had access to NASA satellites that he may have come to a different conclusion. One of NASA's satellites has capabilities to monitor the Earth's radiation close to the surface. As a result, researchers today have been able to study skin pigmentation and the exposure to solar radiation and find that there is a perfect gradient and strong correlation between the two.

Therefore, skin color is a product of evolutionary forces as human adapted to their environments and their skin adapt to the levels of radiation that…

Godzilla (1954) was the original science fiction class that inspired a large number of sequels over the next twenty years, and as usual with this genre reflected contemporary Cold War fears and anxieties about nuclear weapons. In this case, hydrogen bomb tests is the Pacific created a radioactive dinosaur that made its way bad to Japan and destroyed okyo. Japan's cities had been firebombed into destruction during World War II, and it was the only country in history to ever experience a nuclear attack -- just nine years before this film was made -- so the idea that some prehistoric monster might devastate the country had a special relevance there. In the 1950s, of course, there were many science fiction films about radioactive monsters, such as the giant ants in hem or the dinosaur that attacked London in Behemoth, so the symbolism of these mutations destroying the world was commonplace.…

This is what happens in the climax of Godzilla, when a reluctant scientist, Professor Serizawa, uses a new super weapon that destroys all the oxygen in water and kills Godzilla in Tokyo Bay. Serizawa is a wounded veteran of the Second World War, missing one eye, and does not want the world to possess another terrible weapon like this. He decides to destroy all the records of his research and then dies in Tokyo Bay with Godzilla after placing his oxygen destroyer near the monster. By the standards of 1954, the special effects in the film were quite advanced, and the actor wearing the Godzilla costume had the best role, although the monster looked quite impressive when it breathed out radioactive fire all over the models of Tokyo. A young Aaron Burr also had an early role in this film as an American reporter covering the Godzilla story as the creature goes on a rampage.

At the beginning of the film, a ship is destroyed in a mysterious explosion and a salvage team is sent to investigate, but their ship is also blown up. On Odo Island, three survivors from these ships report that a giant monster was responsible, while fishermen report that they are unable to catch anything. This is when an old man first mentions the name of Godzilla, an ancient Japanese legend about a dinosaur that lives in the ocean. That same night, during a typhoon, Godzilla actually comes ashore and destroys some houses, and a scientific team is sent from Tokyo to investigate. They discover that Godzilla is a radioactive monster that has been disturbed by the recent hydrogen bomb tests in the Pacific, and has already destroyed a number of ships in retaliation. Although the Japanese navy drops depth charges on the monster, conventional weapons do not seem to have much effect, which is when the scientists turn to Professor Serizawa.

At first the scientist denies that he has created a new weapon, but the truth is that he does not want the world to know about it since it could cause the extinction of all life on earth. He shows his fiance Emiko what it can do, by testing a small sample in a fish tank and turning every living thing into a skeleton. Emiko is horrified and agrees to say nothing about the weapon, although shortly afterward Godzilla comes ashore twice and destroys Tokyo. With the city in ruins and Godzilla still sitting at the bottom of Tokyo Bay, Serizawa agrees that the weapon must be used, but he makes sure that he will die with it. He goes to the bottom of Tokyo Bay in a diving suit and places the device near Godzilla, but then cuts his own air hose and remains in place when it detonates. Godzilla is reduced to a skeleton and sinks to the bottom of the bay, although he returned many times in the sequels.

Also the alternative voice over IP providers such as Vonage, at & T. is expected to enhance the market share during the period. The demand for wireless connectivity by the direct consumers will also increase having wide choices to choose from like 3G, Wi-Fi, WiMAX. The SSLs and VPNs will dominate in the field of single-user remote access while the IPSec based installations will be resorted to in respect of the network-to-network use. And finally the WiMAX-based services are expected to influence the overall market.

eferences

Carew, Sinead. "WiMax May Pose Fresh Challenge to Broadband" (3 February, 2005)

etrieved at http://www.reuters.com/newsArticle.jhtml?type=technologyNews&storyID=7749299. Accessed on 10 March, 2005

Gabriel, Caroline. (2005) "WiMAX Ambitions Depend on Success in Newly Available

Spectrum" etrieved at http://www.wimaxtrends.com/feature.htm. Accessed on 10 March, 2005

Home Entertainment Networks" (2002) etrieved at http://www.ruleweb.com/wdvl/homenetworking.pdf. Accessed on 10 March, 2005

ILECs Headed for Extinction, According to META Group" (January 30, 2005)

The…

References

Carew, Sinead. "WiMax May Pose Fresh Challenge to Broadband" (3 February, 2005)

Retrieved at  http://www.reuters.com/newsArticle.jhtml?type=technologyNews&storyID=7749299 . Accessed on 10 March, 2005

Gabriel, Caroline. (2005) "WiMAX Ambitions Depend on Success in Newly Available

Spectrum" Retrieved at  http://www.wimaxtrends.com/feature.htm . Accessed on 10 March, 2005

Keystone Species

In mid-1800's, telegraphy was invented. This invention was revolutionary because it decreased all the hurdles in communication of information. This type of invention or any innovations that connects two or more people and acts as a survival tool for a particular group i.e. ethnic or technological group is known as Keystone specie. Even though Specie is a term mostly used for living organisms, here in a larger context keystone specie is referred to as "a system of people, practices, values, and technologies" that is essential for the survival of anything. (Johnson, 2010)

The keystone species concept has been a mainstay of the ecological and conservation biology literature since its introduction by UW zoology professor Robert T. Paine in 1969. His seminal paper extended the conclusions of a field experiment published three years earlier. The research resulting in the keystone species concept was done on Makah Tribal lands on…

Bibliography

Johnson, S. (2010). Where Good Ideas Come From: The Natural History of Innovation. London: Penguins Books Ltd.

Keystone Species Hypothesis. (1996). Retrieved September 24, 2011, from washington.edu:  http://www.washington.edu/research/pathbreakers/1969g.html 

McNely, B. (2010) Exploring a Sustainable and Public Information Ecology, S.Carlos, SP, Brazil.

Nardi, B.A. And V.L. O'Day (2004) Information Ecologies. Chapter 4 in Information Ecologies: Using Technology with Heart. Cambridge, MA: MIT Press

However, their theories, like the catastrophic predictions, lack real, hard, personal evidence. They may be right - but what if they are wrong and civilization does nothing to combat global warming and the other issues facing the Earth?

In conclusion, it seems that many of the people who are so convinced the Earth will survive on its own are ignoring many of the facts. The Earth's survival has depended on regeneration and re-growth in the past, and many species have been eliminated in global events of the past (think of the dinosaurs). During these historic events, man was a blip on the global landscape, or did not exist at all. Today, billions of humans populate the planet and pollute it in a wide variety of ways. The Earth has been able to survive natural events in the past because it was naturally able to regenerate. Today, man has altered the…

References

Bailey, R. Two sides to global warming: Is it proven fact, or just conventional wisdom? 20 Nov. 2004.

BBCNews. Pollution hot spots. 2004

Blackmore, S. Our civilisation will survive the coming climate catastrophe.

Borenstein, S. UN report says climate change man-made. Associated Press; 2 Feb. 2007

Climate change, or global warming, is threating the ecosystems of millions of different species. There are at least 8 million unique species of life on the planet and many of the animals are under a threat that is not due to direct human involvement (alsh). The habitat destruction that is being caused is not something that animal protection acts can address. The problem is with the changing conditions of the environment, these species are losing their habitats altogether or being forced to either migrate or adapt. There have been five extinction waves in the planet's history -- including the Permian extinction 250 million years ago, when an estimated 70% of all terrestrial animals and 96% of all marine creatures vanished, and, most recently, the Cretaceous event 65 million years ago, which ended the reign of the dinosaurs (alsh). Therefore, it could be said that the environmental protection acts or not…

Works Cited

Benzie, R. "Tim Hudak warns endangered species regulations hurting business." 26 February 2013. The Star. Online. 12 April 2004.

Castelnuovo, R. "Case Studies in History and Society." Which Home Do We Protect? The Challenge of Protecting Endangered Species and Property. A Review Essay on Private Property and the Endangered Species Act. Ed. Jason F. Shogren. Austin: Texas Press, 1999. 153.

Debate.org. Should we protect endangered species? N.d. .

Platt, J. "How Much Did the U.S. Spend on the Endangered Species Act in 2012?" 1 November 2013. Scientific American. Online. 13 April 2014.

This occurred in 330 BC, and Zoroaster's date would then be 588 BC, and this date we may take to refer to the initial success of his prophetic mission which consisted in the conversion of King Visht-spa when Zoroaster was forty years old. Since he is traditionally said to have lived seventy-seven years, we will not be far wrong in dating him at 628-551 BC. It seems also to be generally agreed that the Prophet's sphere of operation in which his message was proclaimed was ancient Chorasmia -- an area comprising, perhaps, what is now Persian Khorasan, estern Afghanistan, and the Turkmen Republic of the U.S.S.R. (Zaehner, R.C., 1961, 33)."

Ayala's science takes the mitochondrial Eve back even before what we know about Zoroastrianism, but we really have no accurate date of the monotheistic tradition as it arises out of Zoroastrianism, because there are no written artifacts that support its…

Works Cited

 http://www.questiaschool.com/PM.qst?a=o&d=29306390 

Blackwell, Richard J. 1999. Science, Religion and Authority: Lessons from the Galileo Affair. Milwaukee: Marquette University Press. Book online. Available from Questia,  http://www.questia.com/PM.qst?a=o&d=29306390.Internet . Accessed 3 November 2008.

Dembski, William and Charles Colson. 2004. The Design Revolution: Answering the Toughest Questions about Intelligent Design. Intervarsity Press, Downers Grove, Il.

Dembski, William and McDowell, Sean. 2008. Understanding Intelligent Design: Everything You Need to Know in Plain Langauge. Harvest House Publishers. Eugene, Oregon.  http://www.questiaschool.com/PM.qst?a=o&d=103534752

Intelligent Design

Man has always asked questions about how the world began. All cultures in the ancient world had origin myths. People looked to higher powers, or deities, or life forces, to explain what they could not understand. esearchers do not know where humankind's need for spirituality comes from, but it is clear, looking at history, that faith and the need to believe in something greater than ourselves are part of what makes us human.

The late Stephen Jay Gould, professor of zoology and geology at Harvard University, believed that science and religion were not in conflict. Because they are entirely different, he argued, they could not be synthesized into any common theme (Mitchell & Blackard 2009, p. 146). His is a view that is shared by many scientists who draw a distinction between science and scripture. Science and scripture offer us two different things. One does not have to…

References

Carter, K.L. And Welsh, J. 2010, 'The pedagogy of the debate over evolution and intelligent design', Liberal Education, vol. 96, no. 3, pp. 46-53.

Hlodan, O. 2011, 'Molecular insights into classic examples of evolution', BioScience, vol. 61,

no. 4, pp. 264-267.

Miller, K. Darwin and Christian Faith. . [Distinguished Lecture Series, Pepperdine

Supercontinent Theory

The physical geology of the earth consists of a Core (inner and outer), the mantle, the asthenosphere and the lithosphere. The lithosphere is the crust and upper mantle of the earth that is the hard and rigid layer in which humans live. This portion of the earth reacts to the atmosphere, hydrosphere and biosphere through erosion and weathering, resulting in the soil forming process (Johnson, 2006). These layers of the earth are constantly in motion, giving us the Plate Tectonics, or Continental Drift, theory. Briefly, the theory states that the continents move across the molten plate of the earth -- drifting over time based on the rotation of the earth. The early evidence for this, of course, was that the eastern part of South America and Western Part of Africa fit together quite well. However, studies after 1958 show that there are three major reasons why the "drift"…

REFERENCES

Frankel, H. (2012). The Continental Drift Controversy. Cambridge: Cambridge University Press.

Johnson, R. (2006). Plate Tectonics -- Great Ideas in Science. Minneapolis, MN: Lerner Publishing Company.

United States Geological Society. (2009). Plate Tectonics. Retrieved from:

 http://pubs.usgs.gov/gip/dynamic/historical.html

evolution of eukaryotic cells linked to the increase of atmospheric oxygen concentration during the Precambrian?

Increase of atmospheric oxygen during the Precambrian period led to creatures which were more dependent on oxygen in the atmosphere. Oxygen levels in the atmosphere increased from 1% to 15% of the modern level of oxygen. The increase in oxygen in the air led to the evolution of more expansive lungs which were capable of taking in more air and converting it into energy. As eukaryotic cells evolved, they became more capable of respiration which added to the complexity of the evolutions of creatures.

Scientists believe that if there are no controls on the emission of CO2 from burning fossil fuels, the concentration of this gas could double by the end of the current century, leading to a significant rise in the average temperature of the Earth. What would be some of the likely evolutionary…

Search for Extraterrestrial Life: The Existence of Non-Human Intelligent Beings in Our Galaxy

The possibility of extraterrestrial life has always intrigued philosophers, scientists, theologians and even lay people for centuries. The fascinating question of whether there are other intelligent creatures in space, however, remains unsolved despite technological advancements in science particularly because thus far, there still lacks conclusive evidence. Motivations for the search for non-human life range from scientific and philosophical levels, technical and practical levels, to even the need to eliminate the loneliness of the human race in time and space. Scientists and astronomers remain committed to the search because the answer to this question has profound consequences: it will explain the nature and destiny of intelligent life on the universe, the culmination of evolution in different galaxies and provide more insight on the role of human beings on the universe, as well as what they are capable of…

References

Aczel, A. D (1998). Probability 1. Florida: Harcount, Inc.

Drake, F. (1988). The Search for Extraterrestrial Life. Los Alamos Science Fellows Colloquium. Retrieved 3 June 2015 from  http://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-88-1000-04 

Hawkin, S. (n.d). Life in the Universe. Retrieved 3 June from  http://www.hawking.org.uk/life-in-the-universe.html 

Kelly, M. (2012). Expectation of Extraterrestrial Life Built More on Optimism than Evidence, Study Finds. Princeton University Library. Retrieved 3 June 2015 from  http://www.princeton.edu/main/news/archive/S33/52/89I01/