The evolution of human childbirth can be traced back approximately 2.6 million years ago to our early hominid ancestors, living in the Pleistocene epoch. The human ancestor species transitioned to bipedal locomotion as fundamental adaptations occurred in the pelvis, facilitating an evolutionary shift. The ability to walk upright induced a vital reconfiguration of the birth canal, decreasing and narrowing the shape and orientation of the bony pelvis. These skeletal changes in the pelvis supported body weight and maintained balance while in the upright position, enhancing movement and permitting efficient running and walking. Although the brain of the earliest hominids were not significantly larger than brains of modern chimpanzees, as evolution …show more content…
These difficulties are a result of the biological constraints implemented by the evolution of the narrowed bipedal pelvis and larger brained infants. The physical demands of these adaptations lead to an evolutionary dual over the width and dimensions of the female pelvis. Evolution’s solution for these contradictory pressures resulted in a compromise of design, accommodating an enlarged neonatal brain in the birth canal while maintaining a narrow pelvic structure. The adaptations of pelvic architecture sought to be most suitable and appropriate for childbirth and bipedal locomotion, while providing survival advantages and advancing intelligence. However, the increased cranial dimensions versus a narrow birth canal revealed difficulties as a fetus navigates through the stages of birth. This lead to a change in parturition in our lineage, requiring adaptations to ensure live …show more content…
The human neonatal cranial size matches closely with the dimensions of the maternal pelvis, making it very difficult for the infant to fit through and exit the birth canal. A mechanism called neonatal rotation evolved to accommodate the larger heads and broad shoulders. In the constricted birth canal, the infant rotates multiple times to align it’s head and shoulders transversely in order to exit. The human neonate exists the birth canal facing backwards, making it very difficult for the mother to guide the infant out, extract mucous, and avoid umbilical strangulation, practices seen in our early hominid ancestors. Pulling on the infant when its facing backwards can be very dangerous as well, risking serious neck injury. These dangers lead to a unique adaptation of social assistance in childbirth, a trait unique to humans as non-human primates have a more forward pelvic opening and seek seclusion during parturition. Human infants also depend on social assistance longer, taking time to develop self-sustaining habits before being left on their
In the book, Your Inner Fish, by Neil Shubin he presents the notion of evolution and how we can trace parts that make up the human body back to jellyfish, worms, and even fish. The book not only discusses how we arose to be what we are today, but also the implications our ancestors had on our current body plan. In this essay, I will demonstrate that I have digested the entirety of Shubin’s book by convincing you (dear reader) that everything in our bodies is based on simple changes to already existing systems. To make this case, I will use the evidence of limb development in a vast array of organisms, the four arches found in the embryological stage of development, the structures inside our noses, and how our ears have come about all due to modifications.
After millions of years that humans separated from their relative primate how is that humans became bipedal. So many changes have happened to the human body to decide to stay on the ground and abandoned their lives in the trees. Primates evolved different body structures according to their lifestyle and the ecosystem in which they lived. As Charles Darwin natural selection stays; it could be as a result of new environments, the need for food and shelter, which forced humans to adapt and survive. Although, most of primates’ anatomy reflects habits of movement, it could be easy to see the external differences but there are many differences that have been intensely studied and researched.
In doing this project the literature drawn from is largely non-scholarly for the reason that I am prevailing upon the reader to think outside the box about birth. Most of the “scholarly” research that is available was written by doctors or nurses/nurse midwives who were trained in the medical model of birth. Since part of my premise is that the high rate of Cesarean sections is caused in part by viewing birth as a medical and therefore pathological event, and in part for its emergence as a capitalistic industry, it was then necessary to find literature written by people who have expertise in birthing though not from the traditional obstetrical/medical school approach.
The focus of this paper is to discuss the different characteristics of the two most effective methods of child births: Natural births and Cesarean section (C-section). Child birth includes labor and delivery; the entire process of passage from the womb, to the birth canal, to the outside world. Natural birth is a method of child birth in which medical interventions are minimal and the mother usually practices relaxation and breathing techniques to minimize pain during delivery. Cesarean section (c-section) is a method of birth which involves delivery through incisions in the abdominal walls and uterus. Natural births and C-sections both pose documented medical risks to the mother’s health including infections and other medical mishaps (Rowe- Murray 2002).
Wertz, R., and Wertz D. Lying-In: A History of Childbirth in America. New York: Free Press. 1997
…The infant had been born with anencephaly, or lack of cranial development. The infant’s skull was an open sore that the nurses packed and layered with gauze to give his face a round appearance. Because of lack of cerebral hemispheres, the infant was incapable of any conscious activity. After his birth, the infant was admitted to the neonatal intensive care unit and placed in a bassinet. He was reported to be kicking and breathing, and his ...
Another part of the compromise was behavioral. The loss of a grasping foot is also a serious problem for child-rearing. In chimpanzees and other primates, the young can use their hands and feet to grasp and cling to their mother's fur. For hominid infants, such clinging would have been much more difficult, if not entirely impossible. One of the adaptations to bipedalism must, then, have been a behavioral change toward carrying dependent offspring until they were old enough to walk. (Larsen,
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 magnum, the opening at the base of skull for the spinal column, moved from the back of the skull to the center. The spinal column also evolved from a continuous curve to a spine with four concave and convex curves. (Haviland et al. 2011, pgs. 79, 80). Another change was the widening of the pelvis which gives a wider plateau for more balance when walking on two legs.
Prenatal brain development is not usually the first topic on a pregnant woman’s mind, if it crosses her mind at all! Many women do not know what adverse effects certain circumstances can have on a child’s development. The most obvious deterrent of brain development would be a physical injury to the child. If any portion of the child’s brain is damaged during pregnancy, the effects will almost certainly be long term. Most pregnant women successfully take the necessary steps to avoid physically damaging the child’s brain. Perhaps even scarier is the thought that continuous exposure to stress can also permanently damage the brain development of a child that has yet to be born. The US National Library of Medicine states that in humans and animals, prolonged exposure to stress that can be controlled by the mother may result in abnormal behavioral, cognitive, and psychosocial outcomes. It is important for mothers to remember that they are no longer taking care of only themselves. Though unborn, there is a lot of damage that can be ...
The human infant is called a neonate who is less than 28 days old. (Potter, Perry, Ross-Kerr, & Wood, 2009, p. 333) The newborn goes through mostly reflex changes during this critical time which leads to bonding and deep attachments between the parents and the neonate during the first 28 days. The neonate I worked with was 18 days old, male, Muslim, goes by the initials MK and lived in a townhouse with his parents. During birth, the family requested as many female staff as possible due to religious reasons.
However, many of our questions still remain. The purpose of this paper is to discuss the physical aspect of gender differences in humans, otherwise known as sexual dimorphism, it’s evolutionary history in our species, and some behavioral and societal trends that are associated with it. To accomplish this, I will begin by outlining the anatomical structures that are commonly used in measuring sexual dimorphism in our species. After establishing these criteria, I will expand upon the evolutionary history of sexual dimorphism in humans beginning with the anthropoids in the Oligocene and ending with present day trends.
The version of childbirth that we’re used to is propagated by television and movies. A woman, huge with child, is rushed to the hospital when her water breaks. She is ushered into a delivery room and her husband hovers helplessly as nurses hook her up to IVs and monitors. The woman writhes in pain and demands relief from the painful contractions. Narcotic drugs are administered through her IV to dull the pain, or an epidural is inserted into the woman’s spine so that she cannot feel anything below her waist. When the baby is ready to be born, the doctor arrives dressed in surgical garb. The husband, nurses and doctor become a cheerleading squad, urging the woman to, “Push!” Moments later, a pink, screaming newborn is lifted up for the world to see. Variations on this theme include the cesarean section, where the woman is wheeled to the operating room where her doctors remove the baby through an incision in her abdomen.
One of the most important and pivotal physical and biological adaptations that separate humans from other mammals is habitual bipedalism. According to Darwin, as restated by Daniel Lieberman, “It was bipedalism rather than big brains, language, or tool use that first set th...
The process of human development is very complex. It is a continual process, providing gradual development for the fetus. Some of the most important factors to fetal development such as blood flow, heart beats, muscle development, and brain activity can all be determined within the first seven weeks of pregnancy (Baby Developme...
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 hominids and modern humans really show off how the features and behaviors have really changed in time.