Introduction
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.
The Cambrian Explosion took place in the Paleozoic era where a diversity of life emerged, leading to the lineages of almost all animals living today. Included in this group are chordates, a group of vertebrates, which humans are a part of. Ever since this phenomenon, numerous species have evolved with great changes including Homo sapiens. What happened during the Cambrian Explosion and how did it impact human evolution?
Common Theories
There are several theories about how the Cambrian Explosion started. There were major changes in marine environments and chemistry from the late Precambrian into the Cambrian, and these also may have impacted the rise of mineralized skeletons among previously soft-bodied organisms. One theory as to what happened is that oxygen in the atmosphere, with the contribution of photosy...
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...o happen. But with the help of fossil evidence we are able to identify common ancestors and evolutionary pathways between species. We also identify oxygen as a major key contribution for life to evolve. Also, through scientific research it has been established that arthropods and chordates have shared genes, leading to the path of vertebrates and human life.
Works Cited
http://www.pbs.org/wgbh/evolution/library/03/4/l_034_02.html
http://biologos.org/questions/cambrian-explosion
http://www.darwinsdilemma.org/pdf/faq.pdf
http://science.nationalgeographic.com/science/prehistoric-world/cambrian/
http://books.google.com/books?id=nAh7AgAAQBAJ&pg=PA9&lpg=PA9&dq=cambrian+explosion+human+evolution&source=bl&ots=j--hqsl0WE&sig=q2yEIfk6KKJ-bO2tLKXl2k93z_8&hl=en&sa=X&ei=6px2U82iLY2YqAaf3oGICA&ved=0CJMBEOgBMA8#v=onepage&q=cambrian%20explosion%20human%20evolution&f=false
This way both of the bacteria organisms would be benefiting from a form of symbiosis. Other studies show that prior to the Cambrian Explosion of Eukaryote Organisms the oxygen levels began to soar immensely at about 2.5 billion years ago, followed by the first nucleated cell 1.5 billion years ago. Another important factor to this theory is one discovery made by a professor Kwang Jeon of the University of Tennessee. In 987 he noticed that his amoeba collection were developing large numbers of dots. These dots later turned out to be a bacterial invasion, they began killing of the professor's collection.
The primordial Soup theory was discovered in 1920. According to the Russian scientist A.I. Oparin and English Geneticist J.B.S. Haldane life started in a warm pond/ocean in a process that took place 3.8 billion years ago. A combination of chemicals made fatty acids which made protein. In this process a molecule was born in the atmosphere. The molecule was energized with lightning and rain making “organic soup”. The first organisms would have to be simple heterotrophs in order to survive.
In conclusion, we are successfully able to recreate the ecosystem of two unknown species from the few pieces of information provided to us. It is important to understand the importance of extinct fossils as they contribute to our understanding of life in the past and hold vital information to how the world was back then.
Mass Extinction in the Precambrian As the decades pass, technological advances have enabled researchers, entrepreneurs 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.
Geologic development contributed to the Cambrian explosion. There was a supercontinent called Rodina that broke up to make continents. There was an ice age but the Earth continued to warm creating new life forms. There things called invertebrates that had no backbone. Life forms also had a hard outer shell to protect them. The trilobite is an arthropod that had a hard outer shell. In only 15 million years many different types of organisms evolved. Cambrian reefs made up of sponges flourished.
In absence of calcium carbonate, coral and shellfish can’t survive. The ecosystem of ocean depends on these organisms because they offer a large source of food at the bottom of the food chain. They need to be abundant in order t...
The Jurassic period was the second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 millions years ago, following the Triassic Period and preceding the Cretaceous Period. During the Jurassic Period, the supercontinent Pangaea split apart. Laurentia, the northern half, made up what would eventually form North America and Eurasia. The creation of these opened basins for the central Atlantic and the Gulf of Mexico. The southern half, Gondwana, drifted into an eastern segment that now forms Antarctica, Madagascar, India, and Australia, and a western portion that forms the present Africa and South America. This rifting, along with generally warmer global temperatures, allowed for diversification and dominance of the reptiles known as dinosaurs. Along with dinosaurs, several different types of life and rock formations emerged during the Jurassic period.
In other words, the complex structure of life that we have today slowly occurred over a long period of time. This changed the belief that instead of the earth being only a few thousand years old, it is now several billion years old (5) for that is how long it would take for the earth to develop if the theory of Uniformitarianism is true. Evolution was built merely on a supposition, but it was offered as fact; all the while Evolutionists went hunting for proof.
happen? If not, then why should science teachers teach that life evolved over billions of
Charles Darwin’s theory of natural selection explains the general laws by which any given species transforms into other varieties and species. Darwin extends the application of his theory to the entire hierarchy of classification and states that all forms of life have descended from one incredibly remote ancestor. The process of natural selection entails the divergence of character of specific varieties and the subsequent classification of once-related living forms as distinct entities on one or many levels of classification. The process occurs as a species varies slightly over the course of numerous generations. Through inheritance, natural selection preserves each variation that proves advantageous to that species in its present circumstances of living, which include its interaction with closely related species in the “struggle for existence” (Darwin 62).
[1] This problem with the theory of evolution was addressed by Stephen Jay Gould and other evolutionists. They postulated the punctuated equilibrium theory of evolution, which does not predict the numerous fossils predicted by the orthodox theory of evolution.
That “prehistoric” whales had the jaw of a wolf (a fifty million year old wolf to be exact) and the ear of a whale. I think that all of our semiaquatic mammals play a big part in the evolution of land mammals to water mammals. Like at some point of say an otter’s life, nature told it to stop evolving so that it wouldn’t become completely marine, but semiaquatic as we named it. How did it know when to stop evolving? Was it changes in the environment? Or the need for survival? Which brings around another question, how did we go from a planet of just rock and magma, to a planet thriving with
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 Rise of Life on Earth. New York: New Directions, 1991. Print.
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...