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EVOLUTION AND THE GREATER FACTS OF LIFE
Biology Report
By Genesis Soldier
2015
Indooroopilly State High School

With the discovery of more fossils and ancient remains of past hominid life the theory of our ancestry would be clarified further rather than confusion into understanding our origins as a species. With more remains found and studied theories such as evolution can be strengthened and a timeline of our biological evolution can be further mapped. The theory of evolution by Charles Darwin states "�/Natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps� (M. Denton, 1986). We all know evolution as the slow change of species physical or genetic attributes and alleles over time due to mutation or environmental shifts, what Darwin considered into his ideals of evolution were the following: the theory of evolution, gradualism, species multiply, common decent and natural selection. Darwin contributed more so to the theory and added evidential findings to the side of natural selection in reference to the ideas of evolutionism. The biggest key to explaining and understanding evolution is fossils, fossil are �the remains of past life preserved in rock, soil or amber� (Fossils, 2009). These ancient remains were often the hard parts on the once living organisms; this was usually a part of bone, teeth or shell. Fossils are made by �the remains being buried completely before they decompose� the conditions of the burial must then be suitable for the remains to leave an impression or have their organic material replaced by minerals and survive millions of years of pressure�� (Fossils Formed, 2009) it is through this formation of minerals or impression that we are able to understand and reconstruct past organisms from millions of years ago. Fossils support the theory of evolution by providing a part of a species millions of years ago and can be tested and compared to other fossils of the same species to show changes in the species within time periods and how that species evolved. It is believed our human ancestors started to evolve in Africa around 6 million years ago, at this time there were 15-20 human species but many of these human species had had born no living/ current decedents in the past 5 million years give or take (what Does It Mean To Be Human, 2015).
Question 2
Trends in the Hominid Evolution can be seen and presented through a number of different ways in the field of fossils, whilst the complete skeleton or skull of a hominid is quite rare itself there are plenty of single bones or teeth fragments to study and learn from (Fossil Hominids, 2011).

This is the D2700 skull; it is estimated to be around 1.8 million years old and is currently the oldest and most primitive skull to be presently found outside of Africa (Fossil Hominids, 2011). This skull is used as the start of the Hominid evolution timeline as it is the earliest surviving skull of early Hominid as well as being the smallest and estimates to belong to a matured individual of that time period (Fossil Hominids, 2011). Discovered in Dmansi, Georgia (EX- USSR) and believed to closely resemble the Homo Ergaster the brain size of the D2700 is quite small, due to the estimated age of the skull it is possible that the species of Homo this skull belonged to didn�t use their hands for more complex tasks other than walking on hence the smaller brain size and complexity. With large canines at the front of the mouth and heavily embedded within the upper jaw the fractured teeth show that a large meat diet was present in the Homo Ergaster, this is most likely due to hunting animals but with the molar and wisdom teeth showing a flat enough surface vegetable matter was evidently consumed as part of the diet as well as meat.

This here is the �Mauer Jaw�, whilst not quite complete with a skull a lot can be found by the Jaw itself. Found in 1907 the jaw is estimated to be between 400,000- 700,000 years old with the large and robust jaw belonging to the Homo Erectus the teeth show to also belong to the Erectus species but are in fact smaller and flatter than that of older Hominid samples (Fossil Hominids, 2011). The Mauer Jaw has more edged front teeth and flat molars present within the jaw, whilst missing the canine on the left side of the jaw the more edged tooth structure on the front of the jaw or �chisel� tooth look shows that meat was still a focus of the dietary consumption through the generations and evolution of the homo genus, this species of homo was dubbed the �Homo Heidelbergenesis� (Discovery of Fossils, 2009).

The Petralona skull, found in 1960 and estimated to be of the age 250,000- 500,000 this skull shares more modern skull shapes and size of the Homo Saipen, with a wide jaw and large brain size this skull is further evidence of the evolution of Hominids. Sharing some slight Neanderthal traits the skull has been well preserved and linked to modern day man (Fossil Hominids, 2011). (talk about brow ridges and forehead traits) the forehead of modern day man is smoother and flatter when compared to the older fossil skulls suck as the D2700 and the Petralona skull, this is because of the brain size. As the homo genus began to walk bipedal and use tools their brains increased due to the knowledge and information present that began to function in the path of their evolution. With an increased brain size the cranium began to increase and move forward more to give space for the increasing brain size present in the homo genus of that time, the older skulls like the D2700 have a smaller skull due to the less complex brain sixe whereas the Petralona skull is bigger and more prominent in volume to hold its more complex and larger brain which was developed by using fine tools, walking up right and the use of fire. [REFERENCE]

This diagram is a simple enough timeline showing the evolution and changes within the homo Genus with some of the genetic branches that the early homo family has split into and progressed or died out in. this timeline also shows some of the physical changes within the homo sapiens line over the millions of years, the phenotypes of larger skulls, smoother foreheads, more defined nasal passages and canines are all shown within diagram. It is easier to view the physical changes over the 4 million years this way.
Question 3

With close genetic relation to our more primal ancestor�s apes we can compare and study the physical attributes of the skull and brain size to further understand our Hominid heritage and partial diversity. The Chimpanzee is 98.5% similar to us Homo sapiens (J.Pickrell, 2002) and similar attributes can be found as well as key distinguishing features,
One of the distinguishable features present in that of the hominid lineage when compared to that of the chimpanzee is the forehead. As we [humans] have evolved our brains had become more sophisticated and denser when in comparison to a chimpanzee�s, the human brain averages 3-4 pounds whilst the chimps weight 2-3 (J.P. Bacon, 2000). Reasons for this may include the use of tools, hunting techniques, weapons making and building crude infrastructure. The Chimpanzee brain size is around 400 -500 cc where as the Human brain size is on average 1350 cc, the term cc refers to Cranium Capacity which is the internal volume of the interior of the cranium/ skull.
Our Jaw is also a distinguishable feature that less powerful then the chimp� as we hominids can tenderise our foods more efficiently and have been cooking for ages now which doesn�t require a powerful jaw structure, we have refined jaws due to our different languages and there complexities (what Does It Mean to Be Human, 2015).

This diagram has been scaled to be equal in size, human brain is bigger in reality.
Question 4

The A.boisei, H. habilis, Lucy, A. africanus, A. robustus: when looking at these names it is not that difficult to see the odd one �Lucy�, the research and development on the theory and study of evolutionary science has been furthered through the understanding of past ancestry genus�s and Lucy has not been dubbed with a genus that is abbreviated with a Letter such as A or H.
The A.boisei is a member of the Australopithecus (which is represented by A.) Genus family with the A. africanus and the A. robustus, Lucy herself was before the ancestral split between the Australopithecus and the Homo Genus making her only different from the 5 genus� mentioned above only in name and ancestory as she was before that ape/ human split which has resulted in the Australopithecus and the Homo groups. The H. Habilis is the earliest member of the Homo Genus tree and the only outstanding difference in the above mentioned names as it is the only Homo genus member mentioned in the group of names (J. Naiper, 2012).
Question 5
�Fossils classified in the genus Australopithecus and other early hominid fossils have been found in Africa only and nowhere else in the world�.
Darwin�s theory extends on believing that all human life has been extended from Africa in origins, this belief has so far been supported with the skeletons and remains of both Homo and Australopithecus species (M. Denton, 1986). Geographically there were not as confined to the area of Africa alone but may have stayed with in the vicinity due to Food and well known game trails, shelter and safety or even means such as travelling was impended by lack of water or resources during parts of seasons and or drought. Many if not all early hominid remains have been found within Africa and even tools have been found with the bodies, these tools are found more so with the Homo erectus species and not the australopithecine(Y. Benyene, 2014)...