Mass Extinction in the Precambrian
As the decades pass, technological advances have enabled researchers, entrepenures and pondering minds the ability to discover more and more about every aspect of our very existence. Over the past three decades the evolutionary tree of life has been expanded at least seven times over. Major advances have been made in the area of evolution to open the eyes of many to the extensive history of the earth. For the very first time, we have tangible knowledge that life evolved and grew to become a flourishing success during the young ages of the Earth. By 3.5 million years ago life was already well advanced. Before this breakthrough no one could have thought that life occurred so amazingly early, that Earth was inhabited by a huge array of tiny life forms through t the first four-fifths of it’s existence, and no one deduced that evolution itself evolved over geologic time.
All of geological time, the total history of the earth, is divided into major eras and eons. The Precambrian eon marks the approximate age of the earth and spans a time of 4.6 billion years ago to 523 million years ago. This era is known to include approximately 90% of geologic time and covers 4 billion years of Earth history. The time period is not extremely well known or completely understood because rocks from this era are poorly exposed, many rocks have been eroded or metamorphosed, most are buried deep beneath younger rocks and fossils from this time period and are seldom found. There are three eras included in the Precambrian eon, which include the Hadean, Archean and Proterozoic.
The Hadean era ranges from 4.6 billion years ago to 3.8 billion years ago. Included in this period was a time of major changes in the Earth’s formation. It involves the origin of the atmosphere, volcanic outgassing, and H2O, H2, HCL, CO, CO2, N2, and sulfur gases. Little or no free oxygen was present in this period. The evidence that supports the oxygen theory include: Urbanite and pyrite are readily oxidized today, in modern times, but are found unoxidized in sediments from here, chemical “building blocks” could not have formed in the presence of oxygen and the simplest living organisms have an anaerobic metabolism and would have been killed by oxygen. It also included the origin of the continental crust. Most of the early crust was mafic and the continental developed secondary to that.
The Permian-Triassic Extinction is a mass extinction that occurred between the Permian and Triassic geologic time periods approximately 250 million years ago; it is the deadliest of all extinctions that have occurred on Earth. In addition, during the Permian-Triassic extinction the continents of today existed as one supercontinent known as Pangaea. This was the first time in history where continental or land mass exceeded that of the ocean. This was also before dinosaurs of the Triassic period roamed Earth, during this time animals such as the therapsids, and Synapsids such as the Pelycosaurs, insects and amphibians also occupied Earth. Fauna that existed during the Permian period includes Gymnosperms, or seed producing plants such as the Conifers. Other animals that existed during this time include marine life such as brachiopods (clams), bryozoans (coral-like skeletons), bony fish and sharks, as well as crinoids (sea urchin like creatures). According to National Geographic, about 90 percent of all the animals and fauna of this period perished, the marine life was hit the hardest wi...
Biosphere The Realm Of Life. Authors: Robert A. Wallace, Jack L.King , Gerald P.Sanders – 1998
During the late 18th century, several geologists began to propose an age for earth based on their various studies, and it greatly exceeded the time frame of the Bible. These new studies started th...
Mother earth has gone through a lot of changes throughout its four and a half billion-year existence. Earth has seen many different climates and many different species. Because of these changes geologists have broken earths history into different time periods. One such time period was the Pennsylvanian time period. The Pennsylvanian time period is a subdivision of the Carboniferous period. The Pennsylvanian period saw the introduction of many different species that are still present today along with a very different climate and different geographical features than are present today.
Weisner, Merry E., William Bruce Wheeler, Franklin M. Doeringer, Kenneth R. Curtis. Discovering the Global Past: A Look at the Evidence. Vol.1: To 1600. Ed. 3. New York: Houghton Mifflin Company, 2007. 20-43.
In 1952 W. F. Libby discovered a new method for calculating the age of organic material. Many people have been led to believe that carbon dating (and other radioactive dating methods) prove the Earth to be much older that 6000 years old (Biblical age).
According to the theory of evolution, approximately 3.8 billion years ago some chemicals accidentally structured themselves into a self-replicating molecule. This beginning spark of life was the ancestor of every living thing we see today. Through the processes of mutation and natural selection, that simplest life form, has been shaped into every living species.
There have been significant shifts in scientific discovery since the late 1700s and Paley’s intelligently designed machine argument. Fossils have been uncovered displaying that life on earth has a history. Geology and paleontology have developed a relatively specific age of the earth, and plate tectonics have created separate developmental histories. Darwin showed that organisms evolve and adapt to different environmental conditions. Using the evolution of the flower Marsh Epipactus, it has been shown that nature is not perfect. The flowers were originally self-pollinated which created weak genes and a small population; however, they have evolved to be more successful in their reproduction by preventing self-pollination and encouraging cross-pollination (Gould, pp. 24-26). Many philosophers, including Paley, once believed that what people saw in nature at the time is what people would have seen in the past, and what people would see in the future; however, life on earth has a history that continuously
Throughout Earth’s history there have been many changes. These changes have consisted of temperature fluctuations, atmospheric differentiations, extinctions of various plant and animal life, etc. Over time everything seems to have evolved in some way form or fashion. However, the Permian Era extinction was different from all the rest. This extinction affected every form of life, but especially the marine life. Researchers have stated that 93-97% of all Earths species went extinct during this period of time. This essay will explain how a once blossoming progressive era turned into Earths most catastrophic event.
Herndon J. M, 2005, Current Science, Scientific Basis of Knowledge of Earth’s Composition, 88, 1034-1036)
Audesirk, T. (2003). Life on Earth. In (Ed.), (3rd ed., pp. 581-620). New York: Pearson Custom Publishing - Prentice Hall, Inc..
Additionally, data from a stalagmite taken from Macal Chasm shows evidence of serious drought which make up the most prolonged dry interval of the 3,000-year record, it lasted from A.D 700 to 1135 thereby
“The greatest mystery of existence is existence itself” (Chopra). Chopra, a world-renowned author, perceives the existence of life as a truly mystifying cerebration. The pending question that many scientist, and even theists, attempt to answer is how life ultimately began. Currently, the mystery is left with two propositions, evolution and creation. While both approaches attempt to answer the origins of life, evolution and creation are two contrasting concepts. Evolution views life to be a process by which organisms diversified from earlier forms whereas creation illustrates that life was created by a supernatural being. Creation and evolution both agree on the existence of microevolution and the resemblance of apes and humans but vary in terms of interpreting the origins of the life through a historical standpoint. A concept known as Faith Vs Fact comprehensively summarizes the tone of this debate, which leads the question of how life began.
One argument that supports the panspermia theory is the emergence of life soon after the heavy bombardment period of earth, between 4 and 3.8 billion years ago. During this period, researchers believe the Earth endured an extended and very powerful series of meteor showers. However, the earliest evidence for life on Earth suggests it was present some 3.83 billi...
Francis Crick, co-discoverer of DNA, has said that “the origin of life appears to be almost a miracle, so many are the conditions which would have to be satisfied to get it going” (Horgan 27).2 Noted evolutionary astronomer Frederick Hoyle has described the chances of life having evolved from nonlife to be about as likely as the chances that “a tornado sweeping through a junkyard might assemble a Boeing 747 from the materials therein” (Johnson 106). Why do respected scientists doubt what textbooks teach as fact? It would appear that these scientists know something that current theories describing the origin of life fail to explain. While current theories describe scenarios in which genetic material such as RNA becomes entrapped in a protective cell membrane as a likely recipe for the formation of life, they generally do not focus on the difficulties of forming and concentrating all of these components in the first place.3 To clarify, current theories suffer from what I call the “cookbook mentality.