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 question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have struggled to answer for decades, but why should it matter? Discovering with certainty the cause of megafaunal extinction would simultaneously prove or disprove any of the proposed implications of each existing theory regarding this massive extinction.
paper will analyze the quaternary period, specifically the “Holocene epoch from 8000 B.C. to Present; the last 10,000
In 1977, a recent research by geochemists Eoghan Reeves, Jeff Seewald, and Jill McDermott at Woods Hole Oceanographic Institution (WHOI) is the first to test a fundamental assumption of this ‘metabolism first’ hypothesis. This popular view says simple reaction emerged near ancient seafloor hot springs. These reactions presumably turned a nonliving world to a living one.
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
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).
In 1859, a biologist named Charles Darwin postulated a scientific theory, which stated that all living organisms evolved through a process of natural selection. According to Stephen Hawking, Charles Darwin claimed that the offspring of a particular species gradually evolved themselves genetically to resist the changes in the environment (573). The theory contended that the organisms could adapt to the changes in the environment through the survival of the fittest. Though this theory is regarded as a breakthrough in the field of biological evolution, it is interesting to explore how this seemingly scientific theory has been suitably modified, and intellectually applied to both negative and positive aspects of life.
Paleolithic is often referred to as the Old Stone Age. "Paleo" means old and "lithic" means stone. The Neolithic time period is often referred to as the New Stone Age. "Neo" means new and "lithic" also means stone. The Paleolithic culture or way of life began about 2.5 to 2 million years ago. The Paleolithic Period ended at different times in different parts of the world, generally around 12,000 years ago in Europe and the Middle East. When the Paleolithic period ended, the Neolithic period took over and began 12,000 years ago somewhere in the Middle East, and later in other parts of the world. It is characterized by the beginning of farming, the domestication of animals, the development of crafts such as pottery and weaving, and the making of polished stone tools. Life changed dramatically between Paleolithic and Neolithic times.
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.
The geological time scale stretches from the Precambrian to Cenozoic eras with notable events during each period. The Precambrian consists of soft-bodied life with rare fossils. Fossils in our area come from the Ordovician period. Mass extinctions ended both the Permian and Cretaceous
Therefore, it’s difficult to start a conversation between geologists, archaeologists and historians. It’s vital to narrow the research prospects in these fields but also I think there needs to be more scientific discourse between different fields that affect each other in one way or another. The human historical paradigm is grounded in the research of archaeology. However, Hancock debates that the field of geology has more to teach humans about our history than we think. He debates that around 15,000 to 8,000 BC, during the last ice age, an unprecedented world-wide cataclysm was overlooked that led to the extinction of countless species, including the megafauna (Hancock
According to scientists, one of the most extraordinary bursts of evolution ever known was the Cambrian Explosion. For most of the nearly 4 billion years that life has existed on Earth, evolution produced little beyond bacteria, plankton, and multi-celled algae. Then, about between 570 and 530 million years ago, another burst of diversification occurred. This stunning period is termed the "Cambrian explosion," taking the name of the geological age in which the earlier part occurred. A recent study revealed that life evolved during the Cambrian Period at a rate about five times faster than today. But it was certainly not as rapid as an explosion; the changes seems to have taken around 30 million years, and some stages took 5 to 10 million years. The Cambrian explosion was a period of time where life evolved into numerous multifaceted organisms that developed into the vertebrates and human life as we know today.
Over the past century, the Burgess Shale has revealed important information about the development of earth’s history. The excavation of the Burgess Shale formation provided evidence for what was once just a theory in evolution. The taphonomic findings of the Burgess Shale have played a significant role in understanding the large diversity that resulted from the Cambrian explosion, advancing the study of evolutionary assemblages for Paleontologists worldwide.
“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...