This paper will discuss and outline behavioral and developmental changes in human existence and the reasoning behind the formation of these new distinctions. Several changes in the human past that will be discussed are the change from walking on all four limbs to bipedalism, the greatly increased brain size in humans as compared to earlier humans and the creation of language and communication among earlier species. These distinctions will be investigated and specific reasoning behind their formation will be analyzed.
Explore human lineage through time: April 27, Homo habilis Homo habilis, which dates to between 2. While this species is distinct from the australopiths in many aspects of its cranial morphology size and shapeit also exhibits many primitive traits shared with its ancestor, in this case species in the genus Australopithecusespecially in its postcranial skeleton, which suggest it was more similar to its australopith ancestors than was originally thought.
Compared to australopiths, H. Additionally, the face and jaws of H. Postcranial remains of H.
While only a few postcranial remains associated with H. The phalanges finger bones resemble those of living apes insofar as they are robust thick and curved, but have broad tips similar to humans and attach to the palms in a way similar to humans.
Additionally, some bones of the wrist and attachment sites for flexor tendons tendons that pull the palm of the hand closer to the forearm are more ape-like and have been suggested to be useful while climbing.
Because of the range of variation present in early Homo fossils, there has been controversy over whether H. However, critical examination of the fossil anatomy of these specimens reveals that the patterns of variation expected in a sexually dimorphic species are not present among H.
Furthermore, dental analysis suggests that each species had very different ecological niches. At present, it is generally accepted that H. These tools are very simple, and comprise a core, the scarred center of rock that results from the detachment of one or more flakes the portion of rock removed from original source material by percussion or pressure from a lump of source material.
These cores, while simple, had sharp, cutting edges, and could be used for many purposes. For example, Paranthropus boisei fossils have also been found near stone tools, making definitive determination of which species was a tool-maker impossible. There were several different species, Australopithecus, Parantropus and Homo, extant between 2.
However, this assertion may need to be re-evaluated in light of more recent finds of a species of australopith, Australopithecus garhi, with a smaller brain and larger teeth than H. Speculations as to whether Australopithecus or Homo was the first user of stone tools may have been made moot by the discovery in of markings on animal bones which could have been made only by stone being used to deflesh the bones.
The bones bearing stone cut marks were found at Dikika, Ethiopia and dated to 3. By approximately 2 mya, however, the climate was returning to slightly more warm and humid conditions.
Environmental reconstructions of H. Nevertheless, evidence suggests that in some ways, it was quite similar to species in the genus Australopithecus, especially in aspects of the postcranial skeleton and the small size of its brain. Taking into account body size and shape, locomotion, the masticatory system, and brain size, some scientists suggest that H.
Whether or not this is a valid suggestion depends upon how a genus is defined. Scientists disagree as to whether phylogeny evolutionary relationships should be given priority over adaptive strategies when defining a genus, or vice versa, a distinction that is not easy to make, especially when dealing with fossil specimens.
The variation present at the beginning of our clade a group consisting of an ancestor and all of its descendents suggests that human evolutionary history is more complicated than has traditionally been assumed.Dear Twitpic Community - thank you for all the wonderful photos you have taken over the years.
We have now placed Twitpic in an archived state. acquired trait: A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation (for example, the large.
Essay on Human Characteristics in the Fossil Record. Homo sapiens, the group of tailless, ground-dwelling primates, which are spread internationally and are exemplified by bipedalism and the ability for speech, with a vertical body carriage, which frees hands for manipulating objects.
The fossil record doesn’t demonstrate erectus. Homo heidelbergensis is an extinct species or subspecies of archaic humans in the genus Homo of the Middle Pleistocene (between about , and , years ago), known from fossils found in Southern Africa, East Africa and timberdesignmag.comn H.
heidelbergensis has a several subspecies. The subspecies are Homo heidelbergensis heidelbergensis, Homo heidelbergensis daliensis, Homo heidelbergensis.
The table below presents an abbreviated geologic time scale, with times and events germane to this essay. Please refer to a complete geologic time scale when this one seems inadequate.
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The Biological Sciences.