Evolution of Human System
Human Hearing System
The human auditory ossicles have undergone numerous transitional adaptations. Earlier studies to the fact that human ear developed from the lateral line. However, recent investigations dispute this assertion. Mammalians use tow bones for hearing. These two bones are also responsible for creating balance and sound detection. Mammals evolved from amphibians, primarily primitive fish. The inner ear was formed during Devonian period. According to , the nerve cells in the human ear came from adaptation of the hair cells. Our ancestors are presumed to be using their ears for breathing. The gill-structures that enabled sea creatures to breathe using the back of the heads formed part of the tubes in the middle ear. Our hearing ability relies on these structures. All vertebrates and human use similar bones for hearing. However, human hearing developed complexity as humans established in the land. A close study of hominid reveals that human ear has undergone numerous evolutionary changes that mainly occurred in the bone structures. A study by Texas university also outlines that the hearing ability have evolved from what it was in the ancient times.
Human Vision System
Despite having simple anatomy, the human eye is an essential part of the central nervous system. According to Darwin theory, the human vision system is controlled by specialized proteins and protein system without which vision is obsolete. These proteins were present in eyespots. However, they were only limited to light and cannot tell the direction light or shape of objects.
The human ability to see with both eyes in a similar way helps in judging distance of objects. This ability is only common in humans. The various structures and forms of the eye have evolved from the underlying protein and molecules. These molecules are able to detect different light wavelengths. As a result, the photoreceptor cells developed multiple pigment and this gave rise to color vision (trichromatic). Trichromatic color vision emanated from the effects of three color receptors in the eye. It is argued that color vision developed as a chemical adaptation and not mechanical adaptation during the onset of eye evolution. Different vision ability also evolved as the receptor disintegrated to rods and cones.
The Modern Human brain
One of the remarkable findings concerning the modern human brain is the fact that it is shrinking with time. The early primates had slightly larger brains as compared to the modern man. This has been attributed to the evolutionary effects. One of the notable changes in the human brain is the erosion of grey matter. As the brain became smaller, the inner workings became complex and this has affected the reasoning capacities of humans. The neocortex forms the larger part of the brain and it is divided into further functional regions. Other adaptations that have occurred to the human brain include the expansion of insular cortex and prefrontal cortex. This is one of the distinctive morphological feature of human brain. The cerebral cortex has played a major role in the explanation of the evolution of the brain since it is responsible for diverse cognitive abilities. This primary cortex has grown from underlying structures that determined its size and the amount of information it can process and store.
The driving force behind brain evolution is the ability of the brain to adequate process the information in the environment. Because of diverse genetic evolution coupled with environment pressure, the modern human brain has been adapted to process vast information and thus respond effectively to environmental challenges and increase chances of survival. One of the iconic developments that have taken place in the human brain is the endocranial enlargement which has made the brain the most efficient system of the body. Neuroimaging studies have pointed to the fact that human brain size is double that of chimpanzee as early as 16 weeks into gestation. During infancy, the human brain experiences an increase in the volume of the white matter. However, numerous factors have been cited that limits the brain size of human in the course of development. These constraints can be energetic and neural processing in nature.
The Human Hand
The human hand is said to have evolved from fish fins. Unlike apes, human hands have longer thumbs than fingers. The modern humans have distinct hand variations which can be explained from the evolutionary changes. Drawing from a common ancestry, both hominids and chimpanzee have had similar anatomical expression in the limbs except for minor differences. This supports the notion that the chimpanzee-like walking ancestors preceded the current human bipedalism.
The changes that have occurred in human hand have been minimal since the hand had limited functionality that could alter its anatomical structure. The human hand evidently has had a short thumb to finger ratio.
The human Locomotor adaptation
Locomotor learning is one of the essential aspects of human behavior. The ability of human to practice split-bent walking relies on proper coordination of the legs. Efforts to gain a walking pattern increase the locomotor adaptations. Locomotion entails a functional network that involves the spinal cord. Some studies have insinuated that human were walking with four limbs before evolving into bipedalism. Even though bipedalism has ancient roots, the earlier hominids were characterized by short legs, curved fingers and toes, and long arms. This could be explained that they would not move around frequently as the modern human does. As the evolution progress, the legs of human evolved to accommodate the environment demands.
The earlier primates never used clothing. The skin was constantly exposed to environment strain such as sun effects and rain. Thus the skin pigmentation was determined by the environment. Being the largest organ of the body, the skin has undergone complex structural and evolutionary changes. The skin of earlier hominids was more hairy as this to protect them from harsh environmental conditions. The modern human is less hairy since the invention of clothing. The skin color varied depending on the amount of UV that the skin is exposed to. The original color skin for human was dark as they resided in equatorial climate. As they began to disperse, those that went to high latitudes underwent genetic changes that led to the loss of pigmentation.
Human spark also refers to the uniqueness of human when compared to other creations. It is believed that there were other human species in ancient times but they faded away living humans alone in the planet as the unique creations. The uniqueness that made humans to survive to date is attributed to human spark. Archeologist believes that human spark began in Europe. Some of the characteristics that defines human spark include ability to reconstruct weapons, walk and run long distance in search for food and water, and a unique form of social communication. There are areas in the brain of human that allows them to use complex tools and construct language.
What are the main difference between a living organism and a stone artifact?
Living organisms have growth prospects whereas stone artifacts are constant as they were made. Every human undergoes growth and development which is often accompanied by both physical and morphological changes. This does not happen to stone artifacts. Stone artifacts are often a creation of human mind to represent the real environment. As the names suggest, living organism have an active role in the environment. They are made of cells and they also exhibit life. they also require energy for sustenance. Living organisms in the environment include animals, plants micro-organisms and human beings. Living organisms are also able to excrete waste from their bodies and also adapt well to environmental changes. Stone artifacts (or non-living organism) have no major contribution to the environment. They are neither alive nor active. They do not exhibit characteristics of life such as growth, response to stimuli, reproduction, and homeostasis. Stone artifacts cannot move on their own and thus need no energy for sustenance.
Specific Ways Modern Human can adapt their mind and body to evolutionary changes
Currently, human has the responsibility to adapt to the dynamism in the world. Apart from the problem of environment disruption, the technological developments are also posing significant challenges to the overall development of the human system. The world has changed from depending solely on agricultural product to industrially manufactured foods. This has been seen to affects the operation of the human system. The earlier hominids got everything from the =ir environment including medication. This has changes since everything is manufactured. Therefore, there is need to adapt one’s diet and lifestyle to accommodate such changes or else risk hampering the operation of the body. A lot of chronic conditions that human develop in the modern society have been attributed to change in the lifestyle occasioned by rapid evolution in the human environment. Furthermore, the current influx in information ahs put heavy burden on human brain. The brain has a lot of information of store and process thus challenging its effective operation. Lastly, we must create time to exercise and also rest from active work. This would give the body time to rejuvenate and gain more energy for further tasks without suffering burnout.