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.
The Smilodon, the most recent type of saber tooth cats, went extinct about 10,000 years ago, around the time when Pangea began separating and breaking up. Sabertooth Cats did not go extinct due to lack of prey. However, around 12,000 years ago (end of the late Pleistocene) sabertooth cats, american lions, wooly mammoths and other gigantic creatures considered the “megafauna” went extinct. A die-off called the Quaternary extinction. A popular theory for the extinction is that the changing in climate during the end of the last ice age, human activity, or a combination of both killed off most large
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
... 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.
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.
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.
Millions of years ago, the earth had a different geographical look and the seas covered vast quantities of land that can now be seen. Many present day coastlines were completely submerged and the waters invaded deep into continents making vast portions of the landmasses an aquatic environment. These aquatic environments supported many different types of living creatures, from large mammals all the way down to plankton, algae, and microscopic organisms like bacteria and such. As time went on and these bodies of water subsided, they left an organic layer that covered the geographic area where it was. This organic matter, overtime, would eventually get covered up and it would form different layers of the earth. Many
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...
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].
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.
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
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