Human Origin

The robust australopithecines or paranthropines had a curved face with a arch for the cheek bones that are formed by connecting the zygomatic and the temporal bones together. The robust australopithecines had a bone ridge on top of their skull called a sagittal crest, which is also attached to the jaw muscles. They had a flexable base just above were their jaw bone connected to their cheek bone. With their really large back teeth (below the cheek bone) the robust australopithecines fossils were known to the researchers as the “nutcracker man”. They used these really large back teeth to eat tough foods and nuts. And their teeth in the front were smaller.

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

Primates have some features that support them for the arboreal life. First, primates have developed grasping extremities with the divergent hallux and nails instead of claws. These features help them grasping branches better. Second, primates have enhanced vision with the optic convergence, which helps them look straightforward. They also have postorbital bar to protect the eyes. Third, primates reduced the olfaction that is not useful for arboreal life. Fourth, comparing to the other mammals, primates have large brain consider to the body size. The large brain helps them to process the complicating reactions, and thinking. Haplorrhines primates have some unique derived traits: the loss of tapetum lucidum, which enhances the vision in the darkness; and haplorhini, which is dry external nose. The anthropoid primates have developed some derived traits. They have postorbital bar with closure, and this makes a complete bony ring surrounds the eyes. They also have fused mandibular symphysis. The Platyrrhines have the dental formula 2.1.3.3/2.1.3.3. The Catarrhines have dental formula 2.1.2.3/2.1.2.3. The Cercopithecoids have the bilophodont molars to enhance the chewing ability. The hominoids are the most developed primates, which have some derived unique traits. They have larger brain, loss of tail, longer arms than legs, broad thorax with more muscles, and highly mobile shoulder.

Chimps for example, have similar hands to humans, however, when using a hammer stone, they frequently use a power grip where all fingers are used to control nut-cracking (Wong, 2004). Here, their finger proportions inhibit easy coordination between the index finger and thumb (Wong, 2004). This is significantly different to that of hominids who have hands and thumbs which are very effective and allow for precise knapping and control over hammer stones. This illustrates that their differences in physical characteristics lead to distinctly different behaviors that cannot be considered the

The studies of primate evolution have been developing throughout the years and now scientists are able to compare and contrast between several types of primate groups. One notable primitive characteristic that non-human primates and human primates have retained is the development and evolution of their dentition. Due to primates having long growth periods, scientists are able to research how primates have different dental characteristics and specializations in modern time (Larsen, 2008). By analyzing teeth, scientists are able to determine several factors, such as similar dental formation, growth, development, and diet preferences (Larsen, 2008).

In the Article “Redrawing Humanity’s Family Tree” by John Noble Wilford, describes how two different skulls challenge the theories of human origins and migrations. The Central African skull, that dates back to nearly 7 million years ago, was assigned to a whole new genus and species because of its apelike and evolved hominid species. The 1.75-million-year-old Georgian skull shows evidence that the first hominids may have been intercontinental travelers who set motion the migrations that occupied the whole planet. Finally a third skull was found that is the same age and shares a resemblance but, the size of the skull suggests that the brain was smaller than expected for H. erectus.

NOVA scienceNOW : 41 - First Primates is a video that mainly talks about Primates who are ancient ancestors of human beings. Primates came out on the Earth 55million years ago when dinosaurs extinct due to collision between an immense comet and the Earth. Plesiadapiform, which is a possibly the first ancestor of primates and human beings, firstly evolved with a mouse-size organism during 10 million years. It existed during the 10 million year with diverse evidences that can show its validity of first ancester of primates. Nails of plesiadapiforms is a critical evidence that they are early ancestors of primates. Secondary proof is a tube-like structure which is found in the middle ear. It happens to be a tube for a huge vessel that goes to the

The eight primates whose sequences were used are: Homo sapiens sapiens (modern human), Homo sapiens neanderthalensis (Neanderthal), Pan troglodytes (chimpanzee), Pan paniscus (bonobo), Gorilla gorilla (gorilla), Pongo abelii (Sumatran orangutan), Pongo pygmaeus (Bornean orangutan), and Hylobates lar (gibbon). Based on morphological similarities, it is hypothesized that Neanderthal is the most closely related species to humans. For instance, both species walk up right, have large brains, were able to develop and create tools and had spoken language—although more research is still needed to say for certain that Neanderthals did have spoken language. Additionally, it is also hypothesized that modern human and Neanderthal are both more closely related to the sister group of bonobo and chimpanzee, then to gorilla, then to the sister taxa of Sumatran orangutan and Bornean orangutan, and lastly the gibbon (the outgroup of this data). Hence, by developing the order of these eight primates through genetic data and phylogenetic character analysis, we can gain a new insight into the evolution of

The “wrist morphology” is more similar to that of African ape/humans than that of Neanderthals or Homo Sapiens (iv.). The reason that this is contradictory to the theory that Lb1 is simply a mutated member of Homo Erectus is that the wrist structure actually forms during the early stages of prenatal development greatly decreasing the possibility that the wrist structure could have been a modified version of modern Homo’s. This evidence would indicate that Lb1 belongs to a species of Homo that branched off before the evolution of the modern wrist structure that was prevalent in more recent

The significance of finding these traits primitive in nature compared to the apes is that it shows how these are specialisations for apes to better access their terrestrial and tree dwelling environments. It also indicates that hominids did not develop these traits and therefore developed a less specialised grasping hand (Lovejoy et al., 2009a). Further evidence to support the hypothesis that Ardipithecus ramidus were both bipedal for tree dwelling life and land living is in the wrist bones. The bones were less fixed with the joints providing mobility to the hand. The most significant feature is the midcarpal joint, which shows increased flexibility that would allow Ardipithecus ramidus the ability to bear its body weight solely on it’s hands whilst moving throughout trees (Lovejoy et al., 2009a). The length of the upper limbs overall would have been difficult to support vertical climbs and aid in reaching longer distances between trees commonly found in arboreal settings (Sarmiento et al., 2011)

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 this unique form of locomotion. While much of the extinct taxa within Hominidae were bipedal, but the degree to which they were bipedal remains the subject of considerable debate. The significant discoveries of fossil hominin remains in the last 40 years have resulted in this debate becoming increasingly focused on how bipedal certain fossil taxa were rather than on the overall process. Although the early hominin fossil record remains poor, evidence points to at least

According to physical evidence, and theories, scholars have concluded upon a whole hypothesis. Based on their knowledge and belief, modern humans diverged from Homo sapiens between 200,000 and 150,000 years ago specifically in Africa, that between 125,000 and 60,000 years ago members of Homo sapiens left Africa, and that these

Human evolution is the gradual process in which people, or Homo sapiens, originated from apelike ancestors. Scientific evidence, particularly in the form of fossils and secondary remains, show that the physical and behavioral traits shared by all people evolved over a period of approximately six million years. Humans are primates. Both genetic and physical similarities show that humans and the great apes (large apes) of Africa, chimpanzees (including bonobos, or so-called “pygmy chimpanzees”) and gorillas share a common ancestor that lived between 8 and 6 million years ago. The volume of fossils found in Africa suggests that most evolution occurred there and is likely the place of origin for early humans. This brings to fruition the “out of Africa” theory, also called the “single-origin hypothesis.”

There has been a great deal of heated debate for the last few decades about where modern Homo sapiens originated. From the battle grounds, two main theories emerged. One theory, labeled “Out-of-Africa” or “population replacement” explains that all modern Homo sapiens evolved from a common Homo erectus ancestor in Africa 100,000 years ago. The species began to spread and replace all other archaic human-like populations around 35,000 to 89,000 years ago. The rivaling opinion, entitled the “regional continuity” theory or “multiregional evolution” model refutes this theory and states modern humans evolved from various species of Homo erectus who interbred with others that lived in

Human evolution according to research started over 6 million years ago. The outcome of the evolution process is the current human beings. Scientific studies have revealed over the years a remarkable affinity between the chimpanzees/Apes and human beings. Even though this reality is not a definitive prove that human beings evolved from apes, it does show that the human beings are in one way or another related to other primates. Scientists suppose that the humans and the primates shared a common ancestor. The subject of what makes humans what they are and their origin has been the exclusive purpose leading to many scientific studies globally (Coolidge & Wynn, 2011). Studies believe that Africa was the origin of evolution millions of years ago. Fossil remains have been discovered in different parts of Africa as well as other regions of the world. Different hominins have been discovered around the world in the last 1 million years. Thus, the different discoveries have led to comparisons between the various species of hominins to clarify on their similarities as well as differences. This essay seeks to explain whether they were distinctively different species or regional versions of the same species.