The Emergence Of Pipedalism Analysis

b. Humerus: If the medial epicondyle points to the right it is a right side bone

*John Guido and Sherry Werner make a point that “The stride leg functions to dynamically stabilize the hip and knee joints in a single leg stance to maintain standing posture for

Research speculates that the modern humans and Neanderthals coexisted in Europe for around 5,000 years. To put that into perspective, 5,000 years is around 250 generations in “human-time.” Sharing about 99.5% DNA with the Neanderthals, the largest bone in the foot may be one of the biggest differences that set the modern humans apart to out-live the Neanderthals. Both Neanderthals and modern humans have arched feet, but the height of heal differs. Dr David Raichlen found that because the heal of the Neanderthal was taller, it proved less spring during running and also stabilized the ankle. This made the Neanderthals known for walking, and to which why the lower heal increased the ability for modern humans to out run its closest cousin.

accommodate this strange position, we have developed a specialized pelvis, hip and leg muscles, and an S-shaped vertebral column. Because these changes can be documented in fossil bone, bipedalism is seen as the defining trait of the sub family Homininae.

Materials for this laboratory included Microsoft excel to compile data, a pen and paper to record data, a 15cm ruler, string, a caliper, and a two meter ruler. Since bones often times vary in width in certain portions of the same bone due to the presence of joints and processes the bone was measured at the midpoint along its length for its true width. Measurements

Primates first evolved from the trees of tropical forests, later to the ground. Through the times of prosimians to human, many characteristics has been represented due to the adaptations to new environments and resulted in evolutionary changes. The Earth has encountered several geological and climatic changes over time. For the primates existed at that time had to adjust itself especially in body configurations and locomotion in order to better survive. It is important to be aware of this information since we are the part of occurring changes as well. Throughout the evolution owing to the transforming environments interacting with natural selection, primates developed their own ways to move better (meaning changes in locomotion) with different types of bodies (meaning changes in body configuration).

From the days of Still we are reminded that structure and function are a primary focus reciprocally interrelated-so much so that the basic structure of the skeleton and the parts that make it up are designed to operate a certain mechanical way. The physiological and deeper functional

Bipedalism is a form of locomotion that is on two feet and is the one factor that separates humans from other forms of hominoids. The first bipeds are believed to have lived in Africa between 5 and 8 million years ago. (Haviland et al. 2011, pg. 78). The evolution to bipedalism resulted in various anatomical changes. To be able to balance on two legs, the skull must be centered over the spinal column. As bipeds evolved, the foramen

The most fascinating facet of obligate bipedalism in certain species as paralleled to species that only participate in bipedalism for small amounts of time, is the bone structure that allows for bipedalism, or either allows for walking on four limbs. Such as with our own pets, as stated in textbook Biological Anthropology, written by Craig Standford, the common dog will often stand on its own two legs, exhibiting bipedalism, but this bipedalism is only facultative, as the dog will abruptly drop back onto four legs after loosing equilibrium. This is due to the variances in the vertebral column of obligate and facultative bipeds. Obligate bipeds, being humans, have exclusively different molded vertebrae that permit for the center gravity

Bipedalism was the first evolutionary change to define the hominid lineage. It was a major evolutionary change that changed the way we move. Bipedalism is the condition of using two feet for standing and walking. Before bipedalism emerged we were walking on all fours just as many animals do presently. Bipedal locomotion dates back to 7 million years ago with one of the candidates which is Sahelanthropus tchadensis. The other two candidates for the earliest bipedal hominid are Orrorin tugenesis, and Genus Ardipithecus. This evolutionary change brings about several benefits such as being better adapted to live on savannas, having freed hands, more efficient for travel, and better regulation of body temperature. However, similar to many evolutionary changes, Bipedalism comes with “costs” or disadvantages. These disadvantages include our loss of speed, and more stress on lower body joints including the spine.

Based on Chapter ten from the textbook, there are seven distinct differences of a bipedal hominin like us humans, and a quadrupedal pongid, such as a gorilla (Larsen, 2014). One of the seven steps include the length of the leg, shown in humans to be long which gives us proficiency when striding or running unlike apes that have long arms for climbing on trees. A second step is the opposable big toe found only in apes that give them the capability to take hold of objects and walk. A third step of the seven is the position of the foramen magnum, which in humans is on the bottom of the skull while in apes it is in a posterior position. Overall, the difference is found in that the human head rests on top of the body while the ape head sits in the front. Lastly, a fourth step is the shape of the spine. Humans have an S-shape and apes have an almost C-shaped. Humans have numerous curves to assist in maintaining balance when standing up.

Walking upright with two legs is a common daily phenomenon, however, the ability of moving with only two legs is the result of millions of years of evolution and adaptation. During the process of human evolution, the appearance of bipedalism, which describes the terrestrial locomotion where animals move with their rear limbs in the form of walking, hopping or running, is considered as one of the major steps that sets Hominin group apart from other primates. Even though the transition from quadrupedalism to bipedalism has major drawbacks that sacrifice the flexibility and prevent bipeds to effectively practice arboreal locomotion, it provides a new form of locomotion and frees both hands to be capable of completing other projects while

But why was bipedalism so critical to human evolution? It is the earliest human feature to have evolved in hominins. Darwin felt that it was to free up the hands for making of tools and weapons. However, the first stone tools don’t appear until approximately 2.5mya, many years after the first evidence of bipedalism in hominids. A more logical explanation may be that bipedalism was selected simply because it is superior to walking quadrupedally. The Efficient Walker theory argues that bipedalism enabled hominids to travel further to locate food and fertile territory which coincided with the disappearance of Miocene forests and emergence of savannas in Africa.

The knee is a hinge joint which gives the legs mobility. The muscles and ligaments of this joint allows flexion and extension of the leg. “Because the knee supports the majority of the body weight, it is at risk of overuse and traumatic injuries” (France). The knee is composed of 3 major bones; the femur, tibia, and the fibula. The femur is the biggest bone in the human body, the inferior end flares out into two rounded landmarks called femoral condyles. Their name comes from the side of the body they are on, which is where we get Lateral Femoral Condyle and Media Femoral Condyle. Superiorly to these condlyes are the medial and lateral femoral epicondyles. The bones inferior to the femur are the Tibia and Fibula. The superior end of the Tibia flares out into slightly concave structures called the Tibial Plateaus. A crescent wedge shape of cartilage sits in each plateau. These are the Medial Meniscus and the Lateral Meniscus. This cartilage acts as a shock absorber and distributes forces. “The menisci are bathed by the synovial fluid of the knee” (France). The meniscus is what separates the each side of the Tibia and Femur and the transverse ligament connects each menisci. There is a circular bone on the

The human foot is an example of micro-evolutionary and macro-evolutionary changes. It has had to adapt to bipedal walking and the stress that is caused by being upright. To identify changes in the human foot; comparative, molecular, and biocultural approaches and their paradigms are used. Therefore, different, and cumulative approaches are needed to make informed hypotheses in biological anthropology. The foot will be shown as an example of approaches commonly used and the resulting perspectives in biological anthropology.