Please note! This essay has been submitted by a student.
The ability to see true beauty formed from the earth is one of the few penniless pleasures the world has to offer. Sculpted from high speed winds or shaped from running water the earth has learned to evolve. Living on a planet whose timescale measures back billions of years can make a human feel much smaller than the piece of dust they will eventually become. Early civilizations believed the world they very well knew formed from a big boom in the sky or some other catastrophic event sent from God. This is known to scientist as catastrophism a belief that the earth formatted from some disastrous way.
Uniformitarianism is a more recent study about the earth forming from natural occurring processes during its billions of years. No matter the belief scientist have used innovative technology to discover things about the earth that people a hundred years ago couldn’t even imagine. Billions of years in process the earth was able to come up with the perfect balance of natural resources to sustain life. Living in space the Earth is the third planet from the sun. The ocean covers seventy-one percent of the earths surface. Once being hot enough to fill a magma ocean, the earths ability to change due to the circumstances its in, surpass any life form inhabited on the planet. Withstanding craters from other planets and moons, earths position in the solar system is supreme.
What makes earth the right planet for life goes down to its size, atmosphere, time for essential core to start, and place in the solar system. They often call it the goldilocks scenario because everything is just right for the little earth. If earth was ten percent closer to the Sun, it would be too hot to form life. Mirroring, if earth was ten percent further away it would be too cold to support life to the point all liquid would freeze. Earths perfect size and place prevents it from more hostile atmospheres like larger planets have where life couldn’t exist. If the earth was smaller it would be faced with a similar problem the gases produced would void any life. The lithosphere the earth has over the asthenosphere played a significant role in the earths early development. It made the land livable to life.
Without the lithosphere the plate tectonics wouldn’t work and the world as people know it would be void of mountains and ridges. The earth would be covered in at least a few kilometers of water. With a core that’s magma hot it’s hard to believe so much life exist above it. However, without the molten metallic core most life forms wouldn’t be able to live. With the flow of iron in the core earth cannot support a magnetic field. This keeps the cosmic rays from destroying earths surface atmosphere. Coming into existence 3.8 billion years ago earth it took about a billion years for the earths atmosphere to become inhabitable. Then a billion or so years later Earth gets hit with a giant asteroid causing species of all kinds to become extinct. With the widespread belief and T.V. show out there the Big bang theory is a concept many accepted for the answer to how the early earth formed. With all the questions we ask ourselves in the world the most common one probably is how the earth and life itself came to be. All starting with hydrogen and helium these two light gases collected debris and went through the nuclear fusion process and held high radiant energy.
Radiant energy at the core of these stars was compared to cosmic rays an extreme heat. Forming together with other elements the big bang theory was born. Growing more massive then the sun these Stars caused cataclysmic events to occur. These stars were known as supernovas and are what created the atoms that everything is made of. It all started from this big explosion billions of years ago. Not alone the earths existence formed in the solar nebula. With no greenhouse effect the earth would be drastically different then the way it is today. The atmosphere is what gives the earth that extra layer of protection without it the earth would be 60 degrees colder. Made from mostly nitrogen and oxygen the atmosphere also contains tiny amounts of other gases. The cycles that make earth the perfect place for life would be changed and life as it known would be nonexistent. Changing everyday the 4.6-billion-year-old atmosphere was much different back then than it is today. Generating from a process called outgassing where the inside gases of the planet are released. Still a valuable modern earth function active volcano continues the outgassing process today. The ocean forming was result in the earth cooling and the water vapor that was left condensed into clouds and abundant rains began to pour. The first photosynthesis began in those oceans giving birth to whole new life. Starting from the first bacteria cyanobacteria it helped produce oxygen as by product for photosynthesis. With ocean basins being the source of water 4 billion years ago it contained ninety percent of the current volume of seawater we have today. Such a large part of the earth the ocean also removes carbon dioxide from the atmosphere. It acts as a dispensary helping to cool the earth. The ocean traps the carbon dioxide and it compounds to other elements.
Mostly forming into calcium carbonate. Which is what makes up limestone and covers over shells to make them hard. Trillions of little of tiny marine organisms called foraminifera shells were deposited on the seafloor when they died. This plays an important role in protecting the atmosphere storing the greenhouse gases in their deposits. Measuring earths timespan, its broken down to two eons called Precambrian and the Phanerozoic eon. Within each eon its broken up into eras, periods, epoch, and the development of plants and animals. Precambrian being the larger timescale holds about 90 percent of geological time. Its era less and holds only three periods. Still making up most of time these periods are long starting with the origin of earth at the Hadean period 4000 million years ago.
Next is the Archean period where the first one-celled organism appeared, dating back 2500 million years. Last on the Precambrian sector is the Protectories period where the first multi-celled organisms appeared 542 million years before present time. The more present eon, Phanerozoic has three eras the oldest one is the Paleozoic era where most of the marine animals came about. Holding seven periods of time it is the next largest amount of time seen on the geological scale. Following up in size and time is the Mesozoic era starting with the birth of dinosaurs and ending with the first flowering plants. The smallest era which is most common in our present lives is the Cenozoic era. This era began with the extinction of dinosaurs and ends with mammals developing. The Precambrian time span holds earths first 4 billion years.
Put into ancient range because knowledge these ages are hard to obtain due to all of earths natural processes. Rocks and fossils that old are detreated and eroded. With earth’s crust beginning to form during this eon the hot turbulent mantle recycles this dark material back into the mantle. An ongoing process, the formation of the continental crust is a continuation of the gravitational separation of earths materials. Forming a new material its then taken into another transition in this multi-stepped process where the melting of ultramafic mantle rocks generate in basaltic rocks. Spreading of large continental masses were made by the collision and deportation of different terrains. Within the deepest regions of these collisions zones the sediment from the partial melting and shortening is what thickened the devolving crust. Cartons were the result of these formations of large crustal provinces that with others acted as large crustal blocks.
Pangea being the most popular and known supercontinent out there, contained all the existing continents today. Not being the only supercontinent, that ever-existed its shows in the transformation of landmasses over time. The super continent cycle is the dispersal of one supercontinent and is followed by extended periods in which the fragments are slowly turned into a new supercontinent with a different shape. The movement of continents is no easy task for the earth to endure. What comes with the continental move it has dramatic effect on climate change. The patterns of ocean currents and wind change play a drastic role in this process. It changes the global distribution of temperature and perception. The next eon on the geological time scale is the more recent eon the Phanerozoic time.
Where the birth of the supercontinent Pangea was formed. Pangea is what began the ultimate collisions that continents are what they are today from. These series of collisions brought together North America, Europe, Serbia, and other crustal masses. Trying to date back to earliest forms of life can be difficult but scientist have been able to find fossils dating back 3.5 million years ago. The popular question still unanswered scientist come up with theories to their unknown answers. Resulting in the scientific community bringing it down to life’s essentials DNA, RNA, and proteins. All requiring amino acids, which could have been formed from methane and ammonia. The questions is how did these acids come into existence? Some researchers believe it was delivered from the sky when asteroids or comments hit the earth. It’s been known for them to hold amino acid like compounds. Beginning bacteria was known to be single celled it was called prokaryotes which meant that its DNA isn’t separated from the rest of the cell by its central function nucleus. In contrast to the prokaryotes is the eukaryotes bacteria that is more evolved and contains nuclei.
A new era, Paleozoic gave life to a period called Cambrian where most life forms came about. Mostly animals lacking back bones it gave birth to a large nuber of species. This expansion became known as the Cambrian explosion. What flourished the most was trilobites where more than 600 of these new mud-borrowing scavengers flourished world-wide. Plants weren’t the only self-evolving life forms to adapt their lifeforms to move to land. Some fish had developed strong moving legs and lungs were able to travel to land. These first evolving animals were known as amphibians. Their species can never be known as land animals since they need both water and land to survive. The next considerable time on the geological scale was the Mesozoic Era where reptiles and dinosaurs lived.
Being the first true terrestrial animals with waterproof skin that helped retain their bodily fluids, reptiles had evolved more than just their lungs. This gave them the ability to live a more active lifestyle and lay eggs on land. Dinosaurs lived for 160 million years before becoming extinct. Certain reptiles from this era do exist today and are mostly seen in Florida’s very own backyard. Turtles, snakes, and crocodiles are our modern dinosaurs. Here long before humans these reptiles hold the true means to adapt and survive. The great Permian extinction is what supposedly killed seventy percent of all land species and ninety percent of all marine organisms. With all of earths mass extinction this one by far was the largest. Scientist have come up with many hypotheses as to why an event like this would happen. With guesses ranging from greenhouses gases to volcanoes there still is no proof what happened. The last era and more current to our lives is the Cenozoic time where changes were being made all around. Mammals became the dominate species that inhabited the land now, and angiosperms flowering plants covered with seeds replaced gymnosperms.
This age of flowering plants flourished life not only for itself but other life, Birds and mammals that feed on the plants, seeds, and fruits flourished too. With one demise comes another opportunity the mammals that once inhabited the dinosaurs period are now able to have free range of food. Scurrying around these large and dangerous reptiles, mammals never had a chance to grow. With the mass extinction happening it gave way to the mammals we know today. They had the time to grow brain capacity, and body capability. With all this prosperity some mammals did perish in due time. This was called the Pleistocene extinctions, taking away many species that were once very large in numbers. With all the earths prosperity from the ideal environment the biggest growth has been seen within humans reign the last couple thousand years. Accelerating the planets change hundreds fold then its natural process would humans have made a forever footprint on the world. Even though the answer to big question about how the earth and life started is a big one it’s still constantly changing like time is. It can only leave a person with more questions. Scientist are using modern technology and theories to come up with these answers. Discoveries are made every day.