Precambrian Era The Precambrian era laster 4600-541 million years ago. During this time, there were no plant life on the planet. Most of the things that were on the planet were rocks. The most common type of rock was Isua greenstone. Most rocks have been eroded away, subducted, or metamorphosed. During this time, the atmospheres and oceans were formed, plate tectonics began to build up continental masses. The air during this time was mostly made up of water vapor, carbon dioxide, and nitrogen. Later on, oxygen was formed from early animals taking in carbon dioxide and releasing oxygen. Scientists know this because oxygen was formed with iron, forming iron oxides (rust); after there were was no more iron to mix with oxygen, so it would accumulate in the atmosphere. After this, clouds formed in the atmosphere and caused huge rain storms causing the oceans to form. Afterwards, the plate techtonics started shifting, and volcanoes made different types of rocks, forming the rock cycle. The very first type of animals during this time were one-celled organisms called algae. Most of the animals during this period lived in the oceans. These animals were fossilised in layers of calcim deposited by cyonobacteria. There were two types of cells. The first one is Eukaryotes and has a nucleus, and the Prokaryotes do not have a nucleous. Geologists also found jellyfish like animals in the ocena in the late Precambrian era. Paleozoic Era Cambrian Period This period was called the Cambrian Explosion because of how it evolved in an extremly short amount of time. During this period, the supercontinent Rondinia formed many other continents. New environments formed in the shallow sea between these continents near the equator. The earth continued... ... middle of paper ... ...hanged, many of the great forests slowly gave way to grasslands to a habitat more suited to the cooler and drier weather. Plant-eating animals had to adapt to survive. Horses became stronger and flourished, so did animals like bison, camels, sheep, and giraffes. Many of these animals were quick and traveled in herds to help them survive. Their predators were also forced to adapt. In the oceans, a new type of algae called kelp made themselves a new habitat in cool, shallow waters which provided food for sea otters. Sharks grew and ruled the seas once again. The biggest shark was the Megalodon, and was almost 50 feet long. Meanwhile on land, Asian and African apes seperated and after several million years later, hominins seperated from their African ape ancestors. The hominins grew the ability to walking on two feet, and started to carry food and tools in their hands.
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.
Molecules were then washed ashore and exposed to heat and sunlight. Through a series of trial and error bases chemical reactions formed cells. The first ones were simple only with the new permeable membrane so it could absorb nutrients. After absorbing so many amino acids it was able to replicate itself. Bacteria now was growing off the undersea volcanoes vents living off of hydrogen sulfide. Some of these developed hard shells and others with soft membranes. Meanwhile tectonic plates during this time were shifting drastically and created mountain ranges which altered rain patterns and led to the falling of even more rain which created rivers. These rivers washed out new nutrients found in land out to the oceans. Minerals from land reacted with carbon dioxide which resulted in the production of oxygen. As temperatures cooled algae created glucose through photosynthesis and released gross amounts of oxygen into the ocean. The oxygen reacted with the metallic ions found in the ocean and cause oxidation which caused the sea to turn a rusty red.
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.
The Pleistocene epoch was a time period of almost 2 million years of repeating glaciation around the globe. This epoch was known for its megafauna that roamed the Earth during the last great ice age. Although this was a time of mass extinction for species that could not adapt to the climate changes, many mammals and vertebrates that can be identified today were found during this time (Zimmermann, 2013). The Pleistocene epoch is an important foundation for understanding life that exists today, including carnivores, herbivores as well as the evolution of humans.
...iod. The glacier formation led to the enormous decrease of the sea level which dried out the swamps. Swamps form because of the water level was high and flooded the forest so the low sea level really affected the huge swamps areas of the Carboniferous period. The climate changed from hot and humid to cool. The plants couldn’t adapt to this change so most of the ones that flourished during the time period died off but it led to new plants forming. Most of the amphibians that were prosperous during this time also couldn’t adapt to the environmental climate change so most died off. The insects also couldn’t live through the change. The reptiles however made it through the climate change. They were able to adapt unlike all the other species they lived with during the carboniferous period. These environment changes eventually led to a new time period, the Permian Period.
The Permian-Triassic extinction event is undoubtedly the largest extinction event the Earth has ever seen. While evidence shows that it occurred over a great amount of time, it was effective in causing the extinction of an incredibly large portion of life on Earth. To such an extent that it took millions of years before any large amounts of biodiversity occurred again. This is why it is also referred to as the ‘Great Dying’.
Rock layers are like a portal through time, they show how animals looked in past and evolved through time. In these layers we see fossils, “petrified” and “preserved” forms of old organisms (Google). Scientists have seen and uncovered many different fossils and some have looked similar but from different depths in the layers. Scientists have found fossils of fish, reptiles, amphibians, mammals, birds, today’s mammals, and dinosaurs. They have grouped these fossils into three periods based on how deep in the earth they were found. These periods are the Paleozoic, Mesozoic, and Cenozoic periods. The Paleozoic period has the fossils that are the farthest down in the layer. These fossils include fish, amphibians, and reptiles. The Mesozoic period is contains all things dinosaur and is in between the Paleozoic and Cenozoic periods. Finally, the Cenozoic period contains the fossils of Mammals, birds, and today’s mammals, such as humans.
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.
...he demise of Neanderthals, their influx put immense demand on already constrained resources, there was little available food during the ice age because only those species best adapted to the harsh environment could survive. Homo Sapiens however, had a different way of thinking and created different tools making them better equipped for hunting, this meant that Homo Sapiens obtained food more easily, which was necessary for survival, this led to Neanderthals being outcompeted and their numbers began to diminish.
Paleolithic age presents the era when key human adaptations evolved in response to a variety of environmental changes experienced at the time. This period of human evolution coincided with change within the surrounding of man. Such included cooling, drying and unpredictable climatic patterns over the time. This increased amount of variability in environmental conditions raised the level of uncertainty and instability in their respective terms of survival, necessitated the man to adopt new habits to increase adaptability to the new and changing surroundings. The evolved structures and behaviors led to specialization to enable coping with changing and unpredictable conditions.
The Cambrian explosion refers to the speedy diversification of new forms of animals arising within the fossil record in the span of about 20 million years. This may not seem to be the shortest time frame, but in an evolutionary sense it was lightning fast. Some of the early fossils are unusually intact and very well preserved. Two of the more famous locations of Cambrian fossil discoveries are the Burgess Shale discovered by Charles Walcott on August 30, 1909 in Canada and the Maotianshan Shales in Chengijang, china.
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.
As glacial ice receded and the climate warmed up, the fauna changed as some animals began to become more scarce, such as fewer mammoth herds for example. The warmer climate brought new sources of meat that had become more readily available over time. Reindeer became a main source of hide, bone, antler, and of course meat.
Earth system refers to the earths interacting physical, biological, and chemical processes. The system consists of land, oceans, atmosphere and poles. The earth system has four spheres, including the geosphere, the hydrosphere, the atmosphere, and the biosphere. The geosphere refers to the solid parts of the earth system, including earth’s rocky crust, mantle, and the metallic core. Within the geosphere is the lithosphere, which only refers to the uppermost layers of solid earth. The uppermost layers of solid earth are the oceanic and continental crust rocks. Just below the crust is the mantle, which is composed mostly of magnesium and iron silicate minerals. The mantle accounts for about 2/3 of the
Planet Earth is home to millions of species of life, including ourselves. It is unique in the Solar System because it is the only planet which is able to support a great variety of life: from basic living micro-organisms to highly sophisticated and intelligent human beings. The planet provides the necessary resources and products to support the biosphere that can support the global living organism’s population. Yet, what factors allow Earth to sustain life? Life as we recognize it requires specific conditions to exist. The most basic of these conditions include components needed by living creatures such as water, nutrients, an energy source, and the right atmosphere and climate. Humans need to breathe oxygen and can survive in moderate temperatures- not too cold and not too hot. The atmosphere is like the Earth’s blanket, keeping it warm and protected. Other planets that we know of do not have the same conditions as Earth, so if life were to be present on other planets they would be adapted to that planet’s unique environment. Living things on Earth have adapted to this planet’s atmosphere, therefore we need the specific composition of Earth’s atmosphere to survive.