Precambrian Era:
The Precambrian Era is when the Earth formed. Earth was barley a spec of dust in outer space and as time went by it gathered ice, rock and more dust particles. It eventually formed into a big rock flying around in space. The Earth was extremely hot and so when it rained the rain would evaporate in mid air or immediately after it hit the ground. But even though it evaporated these great rains cooled the Earth eventually building up water in lower areas creating oceans. The Earths atmosphere was water vapor, carbon dioxide, nitrogen and gases. After awhile oxygen level grew in the atmosphere. The earliest life forms were single celled organisms that lived in the oceans. These organisms used light energy to produce food called photosynthesis. These were called Prokaryotes and Eukaryotes. The evolution of multi celled organisms were Dramatic in change.
Paleozoic Era:
The formation and breakup of continents, mountains, volcanic activity, changes in climate and sea level affected the course of evolution.. Paleozoic Era was restricted to the oceans. Organisms evolved a lot crating the “Cambrian Explosion”.
Cambrian:
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.
Ordovician:
During this period land plants evolved. This was a huge deal. More evolved organisms developed...
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Tertiary:
Mountain building and climate changes happened often in this period, as well as the breakup of Pangaea. Mammals were very popular and they were very different and everywhere. The climate was much colder now. The animals adapted to their environment and diets; meat eaters had sharp teeth for cutting and ripping, rodents had self-sharpening front teeth for gnawing and plant eaters had molars for grazing plants.
Quaternary:
In this period the Earth was very cold and there were multiple glaciers. It was a huge ice age. Scientists say that the reason for the ice age was because of a 100,000-year cycle related to the Earths orbit and shape. Mammals got very big and lived in cold grasslands. These animals were relatives of the elephants. They are mammoths and mastodons. The extinction of these animals was at the same time of the extinction of the ice age.
... and the collection of wild plant foods. This variety may be the result of adaptations to changed ecological conditions associated with the retreat of glaciers, the growth of forests in Europe and deserts in N Africa, and the disappearance of the large game of the Ice Age. Characteristic of the period were hunting and fishing settlements along rivers and on lake shores, where fish and mollusks were abundant.
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.
Wong first discusses the possibility that harsh climate killed the last Neandertals. Analysis of isotopes in ocean sediments, ice, and in pollen from the time of the Neandertals reveals that during a period known as oxygen isotope stage 3 (OIS-3), which occurred about 65,000 to 25,000 years ago, there was a climate shift, from moderate to glacial. However, this was probably not what killed the Neandertals, due to the fact that Neandertal anatomy was even better suited for colder climates, with their shorter limbs, barrel chest, and short stature better at conserving body heat (lecture). It is more likely that the severe and rapid environmental shift resulted in the demise of the Neandertals, which could have resulted in a change from forests to grasslands and a change in plants and animals in a short period of time, even over the lifetime of one individual, and just as quickly it could have changed back. The Neandertals, therefore, would have had to adjust to the new environment quickly in order to survive.
The Pleistocene epoch is a well-known time period thanks to the glorification of now extinct megafauna as well as the proximity to our current epoch. Through the rapid climate changes and glaciation that occurred many times during this epoch, the fauna
The global climate during this time was extremely humid and tropical. Again this helped the swamps during the Carboniferous period prosper. This humid and hot climate led to the outbreak of terrestrial plant life. Large trees grew everywhere which gave off so much oxygen. When the plants and tress died during this time, they sank in the water which didn’t have any bacteria. This made them not get decomposed and it formed peat beds. After many years of peat beds over peat beds, it made coal which is why there were a lot of coals coming from this time. The oxygen level during this time was very high. The oxygen level was a lot higher during this time than it is right now in present day Earth. The oxygen level was so high that insects were as big as today’s raccoons. Because of this scientist figured out why so much animal species back then were much bigger than they are now.
This breaking up of the mega continent of Pangaea allowed for more diversification of plant species and as the continents continued to break apart, plant life became even more diversified. As the continents shifted and moved from one area of the ocean to another the climates began to change drastically which allowed for plant and dinosaur species both to begin adapting to suit their new ecosystems. All the water that was produced by the split of Pangaea gave the previously hot and dry climate a more humid and drippy subtropical weather. Dry deserts took on a greener look. Before the Mesozoic Era, livings things were confined to only surviving in the oceans. It was not until the Jurassic Period that livings things evolved the capability of living on the land rather than just the ocean. Towards the beginning of the Jurassic, plant life evolved from Bryophytes, the low-growin...
...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.
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.
The woolly mammoth was commonly found during the last ice age [2]. These animals were similar in size to today’s elephants but were adapted for living in the extremely cold conditions typical of an ice age [2]. Mammoths had narrower skulls, shorter tails, and smaller ears than elephants do, and they were protected by a full coat of coarse hair that secreted oils and insulated them from the cold [2]. The mammoths also had tusks that they used to clear away snow in their search for food [2].
A whole lot of hypotheses have been used to explain the quick expansion of animal species in the early Cambrian period about from about 541.0 million to about 485.4 million years ago. The most modern explanations for the Cambrian explosion takes pieces of a lot of these hypotheses and melds them together; incorporating genetic, ecologic, abiotic conditions that set the evolutionary wheel in motion. The current state of understanding the Cambrian explosion still remains a topic of open and exciting debate. The processes in the hypotheses can be stand-alone or very tightly interconnected and mutually supporting of another. One can say the complexity of modern Animalia can be attributed to the complexity of the processes that happened during the rapid diversification attributed from an interaction of biotic and abiotic processes in the Cambrian period.
However, it would not be until the dinosaurs went extinct that the mammals would flourish. The evolution of the first mammals had occurred towards the end of the triassic period. Their ancestor who can link this evolution to is the therapsids. The first mammals were small, which was an advantage during the time of the dinosaurs. Since nearly all of the carnivorous dinosaurs were large, the smaller the mammal the more likely it will survive. The extinction of the dinosaurs was most likely caused by a huge meteor colliding with the Earth which is known as the Cretaceous-Tertiary extinction extinction. This
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.
Back in the ice age there were no trees to go climbing in there were not two by fours to go make a deer stand with heck there was barely any wood to start and fire to get warm so there was none of our hunting. Back then they were nomads they would follow the herds of animals and would kill them and follow they never settled down they never learned about animals being in season like we do they didn’t know that during the winter birds would be gone and that deer would be around and that turkey were hibernating. So they would be following the birds as they left and would be making sure that they followed them enough that they could get food they would follow mammoths and get fur and food off of them. Then they wouldn’t have to move for a while so you see that everything that they wanted they had to go get, but they did have some weapons that we have today like back then they had the spear and other weapons that or tools that they mad...
Scientist stigall found that species like to spread out all over the continent so there is a reduce in competition. Then there's a break in the continents and that's what causes speciation. It is leading to speciation because of the limited sources of food in the areas. As time passes the environment changes and so do the species which also leads to speciation.
4. The Paleozoic era began with the Cambrian period, around 540 million years ago. At this time, marine life became very abundant, and the first fish started to appear. Animal families became more diverse 480 million years ago, starting the Ordovician period, which ended