Human Evolution Research PaperEvolution has evolved all the way dating back to early primates, to hominids, into modern day human beings. The progression started 7-6 million years ago with the discovery of fossils of proto-hominids. These proto-hominins were the transitional ape/hominin. The earliest proto-hominin, Sahelanthropus, dated back to 7-6 million years. 6 million years ago, Orrorin lived and Ardipithecus lived around 5.8-4.4 million years ago. These first hominids, australopithecines, evolved around 4.2 million years ago. The first species was the Australopithecine species which included the Australopithecus anamensis, Australopithecus afarensis, Australopithecus africanus, and Australopithecus garhi. These dated back to around 4.2-2.5 million years ago. Next, there is the Paranthropoid species which include Paranthropus aethiopicus, Paranthropus robustus, and Paranthropus boisei. All of these dated to 2.5-1.4 million years ago. By 1.9 mya, one of the early transitional humans was the Homo Erectus. 0.5-100,000 years ago existed the Homo Neanderthals and 0.5 mya to to present exist the Homo Sapiens. Through different species, humans today have finally evolved after going through the earliest primates, to hominins, to today. Fossil evidence has been found to explain the existence of hominins and the progression through the australopithecus and homo genus. Fossils were found in Africa that showed that there were around 12 species that lived 6-1.5 million years ago, although they did not live around the same time. A child’s skull named the Australopithecus with a body that is bipedal, alike teeth, and much of the same foramen magnum as our species was found by Raymond Dart. This animal was a hominin, but not quite close enough to a human, showing a time of intermediates. Another example of an intermediate fossil is the Paranthropus robustus skull (by Robert Broom) which contained a sagittal crest, an elevated bone that is in the middle and peak of the head, not seen in human, but in apes. At one point in time, certain species no longer required this feature, therefore, it did not evolve with humans. This skull manifests the transitional bone structure between monkeys and modern day humans. A fossil that is close to specific human areas is the Australopithecus anamensis which obtained similar limbs that proved it walked on two legs, like humans. Animals such as apes or monkeys are primarily on all fours. Due to the reason that humans utilize two legs and these hominids did as well, it signifies the middle ground between monkeys and humans. Mary and Louis Leakey discovered several fossils in the Olduvai Gorge, in Tanzania like the Homo Erectus fossils showing that arms plus legs were relative to our size, also helping us run farther like today. This would be a little more than half-way due to seeing evolved features we have currently. Environmental stress, a key component causing evolution, including natural disaster, predators, competition, and extra elements. Climate change forced evolution to occur because the changes in temperature caused species to form into others. The Homo Erectus evolved and the first illustration is when the forecast turned colder. The Homo Erectus grew an immense body that preserved heat effectively and developed higher quality hunting skills and tools for food that was more dense since plants were no longer in high availability. Seeing that the weather got wintry, it caused the creatures to change. In order to survive, the species learned how to get food productively and not allow themselves to get too freezing. Another key component, the environment, may have been the cause of bipedal locomotion. The environment was said to be a mixed woodland plus grassland environment, and bipedalism was selected to make it easier to see long distance over tall grass areas. Furtherly, with the environment forcing adaptation, a designated ancestor is the Paranthropus boisei who obtained large teeth that were used for grinding and cracking nuts. However, most of what they consumed was mainly not hard foods, more like leaves.. If their environment did not acquire the hard foods originally designed for, and only allowing them to eat leaves, then the teeth will evolve to have the purpose of eating soft foods.After researching human evolution, it is evident that the progression from primates, to hominids, into modern humans has occurred, however, the pieces are somewhat fragmentary. An instance that is visible is how the link between the Australopithecines and Homo Genus do not acquire the appropriate level of evidence for evolution. Although there is this setback, the fossil evidence listed previously shows quite well the similarities to the human race today, such as how early humans, and modern day humans walk on two feet. Overall, there are multiple causes as to why evolution prevailed from early primates to humans.