Australopithecus Characteristics

What evidence shows the changing from the early hominids to the modern humans? Throughout the human evolution body parts like legs and harms have changed for the better. By the early hominids being biped, meaning they are able to stand and even walk on two feet, it helped them to be able to do more things like getting around more and help with their tool making and hunting. A lot of the fossils discovered were found in the Great Rift Valley in East Africa, which contained many different lakes and small rivers. For many years researchers have been finding new species. These species have been named Australopithicus, robust australopithecines , Orrorin tugenensis, Homo habilis, Homo erectus, neanderthal, and Homo sapiens. These early

The Australopithecine are some of the earliest known hominids and they embody many characteristics that are associated with bipedalism. Bipedalism is a highly specialized and unusual form of primate locomotion that sets modern humans apart from all other living primates as we are the only extant obligate bipeds. Many evolutionary biologists and paleoanthropologists have devoted innumerable research hours to attempting to understand this unique form of locomotion and how it evolved. A number of interdependent morphological adaptations occurred over a long period of time to solve challenges posed by habitual bipedalism. As a result, there are obvious differences that exist between early and late hominin species.

They found that Au. ramidus had very similar characteristics to Sahelanthropus Tchadensis an ancestor that dates to 6-7 million years ago. Ardi had a foot that was primitive and had an opposable big toe which was most likely used to grab on branches. She also had a long and curvy spine just like humans. Its pelvis was large like those of apes and had short and broad shoulders suggesting it had a lower center of mass and could possibly walk on one leg at a time. But it is also thought that it was still spending a lot of time in the trees as well. Thus, why it is thought to be intermediate form of bipedalism it lived in both worlds, walking upright, and climbing trees, equal success in both biospheres. Although Ardi is not the connection to apes it still served to prove that the ancestor of apes was a lot more primitive than we believed. There are still several questions to be answered in this puzzle called our ancestry. It may seem that more questions arise as more clues are found, but that is science, there would be no intrigue left if all questions were

Extinction: Most species become extinct because they can’t cope with the environmental change, and also because of introduced species that turned into competitors for

Afropithecus is a fairly large extinct ape- 50kg, characterized by a lack of a prehensile tail, long snout with procumbent incisors, generalized limb proportions and thick molar enamel. The braincase of Afropithecus is fairly small in size compared to other Miocene apes and Old World Monkeys from the same area. The primitive characteristics of Afropithecus suggest a relation to early catarrhines- such as Aegyptopithecus. And the post-cranial fossil record suggest that it was both arboreal and quadrupedal, similar to the proconsul that Afropithecus is categorized

However the minority of species that branch off from the human evolutionary tree and are either claimed by extinction or evolved down a second evolutionary branch, and what differences existed in them that differed from our ancestors. The species such as Australopithecus Boisei lived in the same time period to that of Australopithecus Africanus and Aferensis. However based off the information (See research booklet) it I notice that the A. Boisei has a significantly decreased brain to body weight

In terms of lower limb proportions comparing Australopithecines and Paranthropus, only a few post cranial remains have been discovered. Comparing the post cranial remains of these genera to those of modern day non-human and human apes can give great insight to the locomotion and stature of Paranthropus and Australopithecines.

Another major phenotype to be discussed is the drastically divergent brain size when compared to other Homo species. The LB1 remains contain a cranium with a volume of 380cm3 (Brown, et al.). When this brain size is compared to a modern Homo sapiens volume of approximately 1300cm3 (Cosgrove, et al), the difference is almost laughable. Instead, the LB1 cranial capacity is more analogous with that of genus Australopithecus, at 450cm3 (Roth and Dicke), which would seem to indicate that the brain size of the specimen is primitively determined.

The Australopithecine are some of the earliest known hominids and they embody many characteristics that are associated with bipedalism. Bipedalism is a highly specialized and unusual form of primate locomotion that sets modern humans apart from all other living primates as we are the only extant obligate bipeds. Many evolutionary biologists and paleoanthropologists have devoted innumerable research hours to attempting to understand this unique form of locomotion and how it evolved. A number of interdependent morphological adaptations occurred over a long period of time to solve challenges posed by habitual bipedalism. As a result, there are differences that exist between early and late hominin species.

To begin this essay, Lovejoy appeals the notion of human uniqueness while focusing on human’s ability to be bipedal. By doing this, he introduces the possibilities of the first bipedal ancestor of humans while focusing the relation to other ape’s morphology. Lovejoy first discusses early Australopithecine as one the possibilities for a last common ancestor with chimpanzee, but quickly moves to Ardipithecus ramidus with their thesis of through examining the morphology and social behavioral structure of a CLCA , A. ramidcus can prove the African ape based models are not necessary. African apes models that are used to illustrate human and hominid behavior have become unreliable. To replace these models, Lovejoy proposes adaptive suites and explains

garhi fossils give evidence that it could have possibly been an ancestor to the Homo genus. One of those characteristics lies within the dentition. The ratio between A. garhi’s canines and premolars is similar to that of the Homo genus, but it is also important to note that other australopithecines, A. afarensis and A. africanus, have similar ratios. However, where A. garhi differs from these australopithecines is in the size and robustness of their molars. Less robust molars could mean that A. garhi was eating less fibrous foods and shifting to a more omnivorous diet. This hypothesis is somewhat supported by the finding of fossilized stone tools near the discovery sites. It is theorized that A. garhi might have used these stone tools to eat meat and marrow from bones, as animal bones found near the discovery site show distinctive cut marks (“Australopithecus Garhi” 2016). Another characteristic that supports its connection to the Homo genus is the shortening of the long bones of the lower arm and the elongation of the femur in the upper leg. Through a comparison of these long bones to other hominin species, this has been a proposed model of long bone evolution from chimpanzees to modern humans. In this model, A. garhi is thought to be the intermediary to this evolution, with the long bones of the arm more comparable to Homo sapiens while the femur had yet to undergo elongation. However, the femur is longer than other

The origin of the genus Homo is widely debated, with several candidate ancestors being proposed in the genus Australopithecu. I believe that Au. garhi gave rise to the genus homo. I believe this to be true because even though it is believed that the Au. afarensis was most likely ancestor of the genus homo, the ancesteral-descendent linkage between the two taxa was difficult to identify, owing the virtual lack of a hominid fossil record in the East African dating to 3-2 mya, the timing during which earliest Homo likely evolved. The Au. garhi was found in Bouri, in Ethiopia's Middle Awash region, and it is dated to about 2.5 mya. The Au. garhi is represented by bones, teeth, a partial skeleton, and a skull. For the first time in hominin evolution,

When australopithecus afarensis was first discovered it was thought to be the ancestor of genus homo, even though "there was a virtual lack of a hominin fossil record in East Africa dating to 3-2 mya, the time which earliest Homo likely evolved" (Our Origins). This, however, changed when australopithecus garhi was discovered later in 1999 in the Hata beds of Ethiopa's Middle Awash (Asfaw, White Lovejoy, et. al,). Au. garhi could possibly be the ancestor of the genus homo. Au. garhi like Au. afarensis had a primitive face projection beneath the nose and a small brain. (Our Origins). However the ratio of the arm to leg length that was found was in Au. garhi much humanlike than apelike. (Our Origins). Due to its physical features including its

The Australopithecines were the first to walk upright, or became bipedal, although rather clumsily. Their walk was unsteady, judging by their bone structure (Figure 1.), and they most likely were quadrupedal the majority of the time. The Australopithecines had a brain about the size of an orange, high up cheekbones, and big molars. They were about three feet tall, and had small thumbs. Australopithecines, while definitely possessing some human characteristics, humans are still much closer to the chimps. Australopithecines were vegetarians; even if they knew that animals were edible, they still had no reliable means of killing animals for food. About 2 million years ago, highly evolved Australopithecines made the

Hominids with a brain absolutely and relatively larger than that of the australopithecines appeared about 2.3 million years ago. These hominids are classified in our own genus: Homo. The earliest species to appear was the Homo Habilis. It was the first of our ancestors to show a significant increase in brain size and also the first to be found associated with stone tools. These characteristics resulted in this species’ placement into the human genus, Homo.